現在の建築物における振動に対する評価としては，「建築物の振動に関する居住性能評価規準・同解説」が用いられることが多い。一方で，その評価尺度に関しては，実験室実験により得られた知見を基に作成されており，居住者の生活空間における振動感覚とは異なることが考えられる。また，実際の生活環境で道路交通振動など振動が発生する際に，振動源の通過時に騒音も同時に発生し，人が環境振動に対し騒音を含め複合的に評価している可能性が考えられる。本報では，実住宅において窓の開放時と閉鎖時で振動評価実験を行い，振動感覚評価への影響について検討を行った。その結果，窓開放時は窓閉鎖時に比べて，振動評価と物理量との対応にばらつきが生じる結果であった。

Currently, the " Standard for the Evaluation of Habitability to Building Vibration is often used to evaluate vibration in buildings. On the other hand, the evaluation scale is based on the knowledge obtained from laboratory experiments, which may differ from the vibration sensation in the occupants' living space. In addition, when road traffic vibration occurs in the actual living environment, road traffic noise is also generated at the same time when the vibration source passes by, and it is possible that people evaluate environmental vibration including noise in multiple ways. In this report, vibration evaluation experiments were conducted in a real house with windows open or closed, and the effects on vibration sensory evaluation were examined. As a result, it was found that there was more variation in correspondence between the evaluation and the physical quantities when the window was open than when the window was closed.

近年，ワークスタイルが多様化し，執務空間としての屋外が注目されている．屋外には，屋内よりも執務妨害に繋がる刺激が多く，特に都心では，交通騒音や工事騒音などが頻繁に発生し，それらは統制や制御が困難である．しかし，屋外空間での執務活動において，環境騒音がどのような心理的影響を与えるかについて言及した研究は少ない．本研究では，執務活動時においても，ヒトは屋内よりも屋外にいるときの方が環境騒音に対して寛容であるという仮説に基づき実験をおこなった．

In recent years, as work styles have become more diverse, outdoor spaces have been attracting attention as office spaces. There are more stimuli outdoors than indoors that can interfere with work, especially in urban centers. Traffic and construction noise occur frequently and are difficult to control and regulate. However, few studies have examined the psychological effects of environmental noise during office activities in outdoor spaces. In this study, we conducted an experiment based on the hypothesis that humans are more tolerant of environmental noise when they are outdoors than when they are indoors, even during office activities.

我が国の道路交通騒音の予測モデルASJ RTN-Model 20¹8 では，回折点の計算は3 次元空間における幾何学的最短経路を用いることを想定している。一方で，2 次元平面座標を基にして回折点を近似する手法が，海外においてノイズマップを作成する目的等で用いられている。ここでは，3 次元空間での最短経路と2 次元平面座標での近似による経路を用いた場合の回折計算値の相違について検討した。両者の方法で計算したユニットパターンのLEA の差を比較した結果，通常の道路条件ではおおむね0～2 dB の範囲であることを確認した。

In the ASJ RTN-Model 20¹8, a prediction model for road traffic noise in Japan, the diffraction points are assumed to be calculated using geometric shortest paths in 3-D coordinates. On the other hand, diffraction points are often approximated based on 2-D planar coordinates in other countries for the purpose of creating noise maps. Here, the differences in diffraction calculation values between using the shortest path in 3-D coordinates and using the approximated path in 2-D planar coordinates are examined. Comparison of LEA obtained from the unit patterns using both methods confirms that the differences are generally in the range of 0 to 2 dB under normal road conditions.

歯科では口の中で施術を行うため感染リスクが高くなる。本報では、COVID-¹9 等のエアロゾル感染対策として用いる歯科用口腔外吸引装置の騒音の影響に焦点を当て報告する。我々は、歯科用吸引装置に関して、エアロゾル対策の効果、医療従事者へのアンケート調査、吸引開口部および診療中の術者の耳元での騒音レベル測定などを実施した。その結果、口腔外吸引装置はエアロゾル対策に有用である一方、広い周波数帯域に高い音圧成分を含む騒音を発生しており、アンケート回答の医療従事者の7 割が苦痛と感じているレベルであることを明らかとした。患者と歯科医療従事者のために、短時間暴露であっても騒音を考慮した吸引装置の改良が急務であると考える。

Dental treatments, conducted within the oral cavity, inherently involve the risk of infection. This study focuses on the impact of dental extraoral suction devices, used as aerosol infection control measures for COVID-¹9, on the acoustic environment in dental clinics. We conducted a questionnaire survey among healthcare professionals regarding extraoral suction devices, measured A-weighted sound pressure levels of noise emitted by suction devices, and examined the aerosol suction efficacy. The results revealed that extraoral suction devices were beneficial for aerosol control; however, approximately 70% of survey respondents reported discomfort and painful due to high noise levels. A-weighted sound pressure levels ranged from 86.0 dB to 96.7 dB at suction device openings, highlighting elevated sound pressure levels and a wide frequency range, especially in the vicinity of both the dentist and the patient’s facial area during dental aerosol procedures. It is evident that improvements to suction devices, considering noise reduction, are urgently needed for the well-being of both patients and dental healthcare professionals.

2023 年，阪神地区に本拠地を持つプロ野球の2 チームがリーグ優勝と日本一を勝ち取った地元の兵庫県及び大阪府では，球場周辺や繁華街，主要道路にファンらが集い，雑踏が形成され，激しい混雑により正常な通行が困難な状況となった。路上で警備にあたる警察官や民間警備員らも小型の電気メガホンを用いた広報を行ったが，十分な音圧が確保できず，全体へ情報伝達ができていない懸念がある。本稿では，拡声器メーカの観点から適切な拡声の実現のため，雑踏中心部で発生する音の分析や警備の状況の調査を行い，結果を報告する。群集の災害時の避難誘導という視点で考察する。

In 2023, two professional baseball teams based in the Hanshin area, Hyogo and Osaka Prefectures, won their league championships respectively, and one obtained the championship of the 2023 Japan Series. Many enthusiastic fans gathered around the stadium, in downtown areas and on major roads, creating crowds. Due to severe congestion, normal traffic became difficult. Police officers and private security guards guarding the area also used hand-held electric megaphones to make public announcements, but they were unable to secure sufficient sound pressure and could not say they were able to convey information to everyone. In this paper, in order to achieve appropriate sound amplification from the perspective of a loudspeaker manufacturer, we analyze the sounds generated in crowded areas and investigate the security situation, and report the results. This will be considered from the perspective of guiding crowds to evacuate in the event of a disaster.

防災用屋外拡声システムによる拡声音の減衰量は，常に量が一定となる距離減衰だけでなく，空気吸収や風の影響による減衰を受けるため季節によって変動すると考えられる。この季節変動について調査するために，無人観測ステーションを構築して長期観測を行った。その結果，以下が確認された。(¹) 拡声音の減衰量を距離減衰と空気吸収による減衰で基準化した値（ΔL"）は，受音点によってどの周波数帯域が大きくなるかに違いが見られた。(2). 3 つの測定対象地域のうち2つの地域において，ΔL"の月毎の平均値が向かい風方向の風速が強くなるほど大きくなる傾向が確認され，ΔL"の季節変動の一部が風向・風速で説明できることを確認できた。

The sound attenuation of sound emitted by outdoor acoustic mass-notification systems for disaster prevention varies with the season because it is affected not only by distance attenuation, which is always constant, but also by air absorption and wind effects. To investigate this seasonal variation, we set up unmanned observation stations and conducted long-term observations. The results confirmed that: (¹) The attenuation normalized by the distance attenuation and the attenuation due to air absorption (ΔL") differed depending on the measurement site, (2) At two of the three sites, the monthly mean value of V tended to increase with increasing wind speed in the headwind direction increased, confirming that part of the seasonal variation in ΔL" can be explained by wind direction and wind speed.

航空用ジェットエンジンの騒音低減用の共鳴型音響ライナは、同じ共鳴周波数を持つ小さなライナ要素が複数並んでおり、相互に音響的に干渉し複雑な挙動を示す。これに対し伝達マトリクス法に類似した一次元的な管路音響解析を試みたところ、実験結果を良く模擬する結果を得ることができた。このことより、単一の共鳴器の特性が得られれば、それらが複数並んだ音響ライナ全体の特性を簡易な計算で推定できることが分かった。管路音響解析では各要素の効果を詳細に調べることができるため、音響ライナ内で何が起きているかを理解し、音響ライナの性能を向上させるための手掛かりを得ることができると考えられる。

A resonant acoustic liner for noise reduction in aircraft jet engines consists of multiple small liner elements with the same resonant frequency, which interfere with each other acoustically and exhibit complex behavior. One-dimensional duct acoustic analysis, similar to the transfer matrix method, was attempted, and results that well simulated the experimental results were obtained. This indicates that once the characteristics of a single resonator are obtained, it is possible to estimate the characteristics of the entire acoustic liner with multiple resonators in a row by a simple calculation. Since the effects of each element can be studied in detail in the duct acoustic analysis, we can understand what is happening in the acoustic liner and obtain clues to improve the performance of the acoustic liner.

タービン、圧縮機などの流体機械の翼は非定常な流れ場で作動するため振動が原因でトラブルを起こす場合がある。そのうち可能性が大きいのは非定常流体力の振動数と翼の固有振動数が一致して生ずる共振による高サイクル疲労で破損する場合である。著者はこれまでに、動翼が流体励振力を受けて共振する現象を扱い、非定常翼理論の適用性を研究してきた。最近ではCFD を翼列内部流れに適用し動・静翼の干渉による非定常空気力を求める試みもなされるようになったが、古典的理論の有用性についての議論は少ない。そこで、単独翼理論を紹介し、翼の共振解析に適用した結果および翼列の曲げフラッタ理論を紹介し、フラッタ解析に適用した結果を述べる。

Blades of fluid machinery such as turbines and compressors can experience issues due to vibrations because they operate in unsteady flow fields. One significant potential problem is high-cycle fatigue resulting from resonance, where the vibration frequency of unsteady fluid forces matches the natural vibration frequency of the blades, leading to damage. The author has previously investigated the phenomenon of rotor blades resonating under the influence of fluid excitation forces and studied the applicability of unsteady blade theories. Recently, attempts have been made to apply Computational Fluid Dynamics (CFD) to analyze unsteady aerodynamic forces caused by the interaction between moving and stationary blades within blade rows. However, there is limited discussion about the usefulness of classical theories. Therefore, this paper introduces the single-blade theory, discusses its application to resonance analysis of blades, presents the results, and introduces the bending-flutter theory of blade rows, along with the application of flutter analysis and its results.

パーソナル音響システムとは、周囲への音漏れを抑え、ユーザにだけ音を届けるための技術の総称である。イヤホンやヘッドホンを使わずに、この目的を達成するには、スピーカアレイを構築し、音波同士を上手く干渉させ、音の届く方向や距離を絞らなければならない。従来研究の主流は、音圧の空間分布の理想と現実の誤差を最小化するような、数理的な方法論である。音源、聴取領域、非聴取領域の配置によって、満足のいく結果が得られたり、得られなかったりするのだが、何故そのような結果が得られたのかを物理的に解釈しにくい。著者らは、物理的な方法論として、放射モードと接線法に基づくスピーカアレイを提案しており、本講演では、それらの研究（既報）について紹介・解説する。

Personal audi system is a hot topic in acoustic engineering. Many earliers works are based on mathematical optimizations such as acoustic contrast control and pressure matching. Though these works are interesting and useful, the obtained results are not necessarily easy to understand from physical perspective. Recently, the authors proposed physics-based loudspeaker arrays: radiation mode-based loudspeaker array; and tangent line method-based loudspeaker array. In this presentation, our earlier works are reviewed.

生活家電に代表される製品を居室で使用する際の音環境を評価するためには，居室の標準的な平均吸音率が必要となる。この平均吸音率を取得するためには多数の居室で測定が必要となるが，居住者のプライバシーの観点から測定は容易ではない。そこで本論では，居住者自身による平均吸音率の測定を目的に，手を叩く音を音源に用いた測定方法を検討した。リビング・ダイニングルームを用途とする居室を対象に測定した結果，本方法による平均吸音率は，Log-Swept-Sine 信号を音源に用いて測定した平均吸音率と比べて13%高く，これは人の吸音が要因であることがわかった。この影響を補正することで，同じ用途の居室6 室を対象に測定した平均吸音率の算術平均値0.17 を得た。

When products such as home appliances are used in a living room, the standard average sound absorption coefficient of the room is necessary to evaluate the sound environment. To obtain the average sound absorption coefficient, measuring the sound absorption coefficient in many rooms is essential. However, this measurement is not easy for the privacy of the occupants. Therefore, this paper studied a measurement method using hand-clap sounds as a sound source for measuring the average sound absorption coefficient by the occupants. Living and dining rooms were the target rooms. As a result, this method’s average sound absorption coefficient was 13% higher than that measured using the Log-Swept-Sine signal as a sound source. This effect is due to the human’s sound absorption. By correcting for this effect, the standard average sound absorption coefficient for six rooms was 0.17.

近年、労働人口の減少により、個人の知的生産性が重要視されている。また、多様な働き方の一つとしてリモートワークで勤務する人々も増加している。本研究は、リモートワークの知的生産性を、音環境の改善によって向上させることを目的としている。書類作成などのタスクを対象とし、カフェやコワーキングスペース等の社外での環境を対象とした。空調音と人の声をベースとして背景音楽、自然音とクラシック音楽を付加音として用いた被験者実験を実施した。背景音楽によるストレスを付加音によって軽減する狙いがある。人によって好まれる音楽が異なることから、リモートワーク施設には、利用者自身が付加音を選択できるサービスの可能性が考えられる。

In recent years, the intellectual productivity of individuals has become more important due to the decline in the working population in Japan. In addition, an increasing number of people are working remotely as one of the various ways of working. This study aims to improve the intellectual productivity of remote workers by improving the sound environment. Tasks such as document preparation were targeted, and the environment was outside of the office, such as a cafe or coworking space. Subject experiments were conducted using background music based on air conditioning and human voices, and nature sounds and classical music as additional sounds. The aim was to reduce stress caused by background noise by using additional sounds. The experiment revealed that different people prefer different types of sound. This suggests that remote work facilities should provide a service that allows users to select their own background sound.

本研究は，余混合火炎である浮き上がり火炎に対して超音波周波数を印加する事で浮き上がり火炎に与える影響の比較を行う．これまでの研究結果では超音波周波数領域内においても周波数の増加によって浮き上がり火炎の燃焼持続時間の増加が確認できた．しかしながら，超音波音源は1 台のみであった．そこで本研究では，超音波音源の数を2 台，3 台に増加して浮き上がり火炎に与える影響の比較を行った．また，角度間隔が燃焼持続時間に与える影響についても検討した．その結果，超音波音源を増加する事によって浮き上がり火炎の燃焼持続時間の増加を確認できた．また，超音波音源の角度の間隔が狭いほど燃焼持続時間の増加を確認できた．

In this study, we compared the effects of applying ultrasonic sound sources to a floating flame by an premixed burner, in which ultrasonic sources were multiplied by 2 and 3. The previous studies, in which the source is only one, have shown that an increase of ultrasonic frequency has accomplished the increase of combustive duration time, and the same tendency was ascertained in this multiplied case. In the angular variation between the ultrasonic sources, reducing angle prolonged the duration time in the most cases.

音源の移動により放射音の周波数や振幅に変調を生じさせる．しかし，音源の移動が放射音の振幅に及ぼす影響について実験的に明らかにした研究例は少ない．本研究では，模型発射実験により空力音のうち音源表面の圧力変動に起因する二重極成分の指向性を計測した．計測した指向性から音源移動に伴う振幅変調を求めた結果，音源移動に伴って音源からの放射音の音響インテンシティは放射音の周波数が音源静止時と比較して変化する割合の約8 乗に比例することが示唆された．風洞実験によって同じ音源の指向性を計測した結果，放射音の音響インテンシティは移流によって流れの中の見かけの波長が元の波長に対して伸び縮みする割合の約4 乗に比例することが示唆された．

Frequency modulation and amplitude modulation occur in the radiated sound due to sound source movement. However, few studies investigated the effect of sound source movement on the amplitude of radiated sound. We measured the directivity of the dipole component of aerodynamic sound caused by pressure fluctuations attached to a moving scaled train model. By calculating the amplitude modulation due to source movement using the measured directivity, we found that the acoustic intensity of radiated sound increases roughly in proportion to the eighth power of the rate at which the frequency of the radiated sound changes compared to when the source is stationary. We also measured the directivity of the same sound source in a wind tunnel with a microphone array outside air flow. The results reveal that the acoustic intensity of radiated sound increases roughly in proportion to the fourth power of the rate at which the apparent wavelength in the flow expands or contracts with respect to the original wavelength due to convection.

新幹線騒音のさらなる低減に向けて，音源別の寄与率を算出することが重要である。本研究では，マイクロホンアレイを用いて実測した車両まわりの音源分布と音響模型実験から推定した音源と観測点間の伝達関数を組み合わせることで，近接側軌道中心から25m 離れた観測点における音源別寄与率を推定する手法を提案した。また，全体騒音に最も大きな影響を与える台車部から発生する空力音について，風洞試験において発生メカニズムの解明を進め，低減に向けた対策の基本的な考え方と具体的な対策例の実証を行った。

To further reduce Shinkansen noise, it is important to evaluate the contribution ratio of each source to the total noise. This study proposes a hybrid method that combines the sound source distribution around a vehicle and the acoustic transfer function between the source and the observation point, 25m apart from the nearest track. The sound source distribution for passing trains was identified using a microphone array in a field test, while the acoustic transfer function was determined through an acoustic model experiment. Additionally, the wind tunnel test investigated the aerodynamic noise generated by the bogie, which has the greatest impact on the total wayside noise. The mean velocity distribution was measured using PIV to clarify the generation mechanism of aerodynamic sound. This provided the basic concept for developing countermeasures. The study also presented several examples of countermeasures, which proved effective in reducing the aerodynamic noise.

道路交通騒音の予測モデルASJ RTN-Model 2018 の定常走行区間の音響パワーレベルLWA の計算式は，自動車専用道路や一般道路で測定した実測データを用いて変更した。一方，本年4 月に発表予定のASJ RTN-Model 2023 では，加速走行のLWA と定常走行のそれとが一致するように，加速走行のLWA 式の定数a と係数b, c を見直すことにした。なお，このLWA の変更に伴う予測結果の違いを試算した結果，1 dB 未満の差異で僅かである。その他，2018～2022 年度にかけて新たに測定したデータを基に，定常走行のLWA 式で設定されている定数などの有効性も確認した。

In the road traffic noise prediction model “ASJ RTN-Model 2018” published in 2019, the calculation equations for the A-weighted sound power level, LWA, of road vehicles under steady running conditions were updated using the measurement data on various expressways and general roads. On the other hand, the equations in ASJ RTNModel 2023, which would be published next month, for noise emission under acceleration running conditions were modified to coincide the sound power levels under steady and acceleration running conditions. The level differences in the prediction results owing to the modifications of the calculation equations for noise emission are less than 1 dB. In addition, the effectiveness of the equations for LWA under steady running conditions were confirmed from the new emission data accumulated in fiscal years from 2018 to 2022.

道路交通騒音の予測モデルASJ RTN-Model 2018 の定常走行区間のパワーレベル式は、単独走行騒音の測定が可能な日交通量がおよそ15,000 台以下の自動車専用道路での測定結果に基づいて設定されている。一方，日交通量が数万台の重交通区間では、路面の劣化が進行し発生騒音が増加することが危惧される。本稿では、重交通区間とパワーレベル調査箇所（対照箇所）の発生騒音の違いを検討するために，重交通区間と対照箇所のLAeq の測定値と計算値のレベル差に着目し，レベル差と各種の累積交通量との関係を検討した。その結果，レベル差は累積交通量に依存せず、重交通によるパワーレベルの補正は必要ないことが分かった。

The A-weighted sound power levels of running road vehicles in steady traffic flow section on the road traffic noise prediction model ASJ RTN-Model 2018 are based on measurement results conducted on automobile highway roads with a daily traffic volume of approximately 15,000 vehicles or less, where measurements of single-vehicle running noise are possible. On the other hand, in heavy traffic highway sections with daily traffic volumes in the tens of thousands, the sound power levels of running vehicles may increase due to the deterioration of road surfaces. In this paper, we investigated the differences of noise emission between heavy traffic sections and control ones where sound power levels were determined. We focused on the difference between the measured and calculated values of LAeq, and investigated the relationship between the difference and various cumulative traffic volumes in heavy traffic sections and control ones. As a result, it was found that the level differences were not dependent on cumulative traffic volumes, and it was determined that no correction for sound power levels due to heavy traffic was necessary.

ETC 料金所前後における自動車の加減速時の加速度およびスマートインターチェンジにおける一時停止時間について実測調査を行い，既往研究で得られているデータと合わせ，ASJ RTN-Model 2018 に則った道路交通騒音予測における料金所周辺の計算条件の設定方法について提案した。料金所周辺におけるユニットパターンとLEA の試算を行い，加減速時に設定する加速度について，実測で得られたばらつきの範囲内の値であれば，平均値を用いて計算を行った場合とLEA の差は小さいことが確認され，車種毎に実測調査で得られた加速度の平均値を用いて予測計算を行うことの適用性を確認した。

Measurements on acceleration while accelerating and decelerating at an interchange and duration of stop time at a Smart IC were carried out. Based on the measurement results, together with the data of previous studies, a calculation procedure at an interchange, including the tollgate with the Electronic Toll Collection system, is proposed in accordance with ASJ RTN-Model 2018. Through case-study calculations, we have observed that the unit pattern at the prediction point around an interchange varies due to the acceleration value set in the calculation. On the other hand, it has been found that the variation of LEA due to the difference in acceleration is small when the values of acceleration are within the range of the variation obtained by the measurements. From these results, the applicability of the calculation procedure using the average value of acceleration obtained by measurements for each vehicle category has been confirmed.

本研究では，等価騒音レベルの予測が可能なエネルギーベースの予測計算方法を提案することを目的としている。そのために，福岡県内に設けられた2 カ所のラウンドアバウトの実測調査を行い，環道および周辺部における騒音レベルの実態を明らかにし，そして，日本のラウンドアバウト周辺部における騒音レベルの予測計算方法を提案した。小規模なラウンドアバウトでは，ASJRTN-Model 2018 に示されている音響パワーレベルを適用して，定常走行の計算式を用いることが可能であることを示した。また，25 点における実測値との対応を検討し，提案した計算方法でラウンドアバウト周辺部の等価騒音レベルを精度よく予測可能であることを明らかにした。

This study was conducted to elucidate the actual situation of noise levels around roundabouts in Japan and to develop an energy-based prediction method to calculate equivalent noise levels around roundabouts. Two roundabouts in Fukuoka Prefecture in Japan were surveyed to clarify the noise levels around them. In small roundabouts typically introduced in Japan, vehicles pass slowly at an almost constant speed. Therefore, setting the sound power level while assuming the steady running of vehicles at low speeds is appropriate. We propose a method of predicting equivalent noise levels by calculating single-event noise exposure levels from unit patterns according to the ASJRTN-Model 2018 prediction procedure. The calculation and measurement results at 25 points around two roundabouts show good agreement. The findings confirmed that this proposed calculation method can accurately predict equivalent noise levels around roundabouts.

建物群による挿入損失に関して，藤本らによる方法の考え方を踏襲し，異なる周波数特性をもち，高い位置にある音源の場合にも適用できる計算方法を構築する基礎データの収集のために模型実験（縮尺1/40）を行った。建物配置は先行研究に倣って設定し，音源高さは0 m（地面上）と10 m とした。高さ0 m の結果をASJ RTN-Model 2018 に示された建物群背後の計算方法による結果と比較したところ良好な対応を示し，音源として新幹線鉄道騒音を模擬した場合も高い対応であった。音源位置が高い場合には既存の計算モデルでは対応が低かったため，音源，受音点，建物の三者の3 次元的な位置関係を考慮する計算法を試行したところ，比較的良好な対応が得られた。

In order to investigate the insertion loss of buildings for various noise prediction, a 1/40 scale model experiment was performed. In the experiment, the building layout was set according to previous research by Prof. Fujimoto, and the sound source heights were made 0 m and 10 m. Comparing the results for a 0 m source with a calculation results by the calculation method included in ASJ RTN-Model 2018 showed good agreement, and almost the same agreement was also seen for a sound source modelled with Shinkansen super-express train noise. When the sound source is high, the conventionalcalculation model had poor agreement with the experimental ones, so we tried a revised calculation method that takes into account the three-dimensional geometrical relationship between the source, the receiver, and the buildings, and found fair agreement.

前報では、円筒座標系をベースとした音場解析に用いるスカラ型のFDTD法を概要を整理するとともに、インパルス応答を得るための初期音圧の配置や境界条件の設定について初期的な検討を行った。本報では、さらに検討を進め、吸収境界での不要な反射波を抑えるために、直交座標系の波動方程式に基づく2 次のインピーダンス境界条件と、これに修正を加えた境界条件を実装した。そして、これらの境界条件の特性の違いを複数のシミュレーションで比較検討した。その結果、修正を加えたMur の2 次吸収境界条件が有効に機能することが確かめられた。

Our previous report outlined the scalar-type FDTD method for sound field analysis based on a cylindrical coordinate system. We discussed setting of the initial sound pressure and setting boundary condition to obtain the impulse response. This report further investigates two boundary conditions to suppress unwanted reflected waves at absorption boundaries. One is a second-order boundary condition that universalizes Mur’s second-order absorption boundary based on the Cartesian coordinate system. The other is its modified version. We implemented both boundary conditions in FDTD simulations and investigated the differences in their characteristics. Simulation results indicated that the modified Mur’s second-order absorption boundary condition is effective.

本研究では排泄時の心理的安全性に繋がる要因としてBGMに着目し, 安心感に繋がるBGM の音量設定について検討を行なった. 流水音, 音楽, それらをMIXしたものの3 種類を音源とし, 調整法を用いた実験を行なった. 結果として, 61dB 程度の音量で被験者の75 %が安心して排泄が出来る可能性が示された. また流水音を含むものはやや小さな音量でも安心できることが示された. また男性は, 排泄音を隠したい意思の回答に依らず, BGM に対して好意的な意見が多くみられ, BGM の活用が安心感に繋がる可能性が示された.

This study focuses on the psychological safety of excretion, specifically examining the volume settings of background music (BGM) that contribute to a sense of comfort. Three types of sound sources were used in the experiment: flowing water, music, and a mix of both, employing an adjustment method. The results indicated that a volume level of about 61 dB allowed 75 % of the participants to feel comfortable enough to excrete. It was also shown that sounds including flowing water could induce comfort at slightly lower volumes. Furthermore, males displayed a favorable opinion towards BGM, regardless of their desire to mask the sound of excretion, suggesting that the use of BGM has the potential to contribute to a feeling of comfort.

道路交通振動の発生要因の検討を本研究の目的としている。前報に引続き供用中の道路において、車両への積載の影響と車速依存性の把握に関わる検討結果について報告する。道路交通振動は、車両重量が増えれば大きくなることが知られている。本報では、車両への積載の有無の影響と車速依存性についての検討の結果を報告している。また、車速依存性の分析を行い、これまでの段差実験の結果の妥当性についても検討している。

The purpose of this study is to examine the causes of road traffic vibration. In this paper, following on from the previous report, the effects of load on vehicles and vehicle speed dependence on roads in service are reported. Road traffic vibration is known to increase with vehicle weight. In this report, the results of a study on the effects of whether or not a vehicle is loaded and vehicle speed dependence are reported. In addition, an analysis of the vehicle speed dependence is being conducted, and the validity of the results of the bump tests so far is also being tested.

本報では，Li,Fmax,r,H(1)-60 程度の実建物に住んでいる居住者を対象に，生活実感を主としたアンケート調査を実施した。建築物の遮音性能基準と設計指針[第二版]のL-60 は「よく聞こえる」という表現であり，本研究では累積相対度数の百分率で74.2%を示した。相対度数が最も多い表現が，「よく聞こえる」であったことからも，建築物の遮音性能基準と設計指針[第二版]の表現は，Li,Fmax,r,H(1)-60 に対して適当であると考えられる。これまで検証されていなかったゴムボールとタッピングマシンの床衝撃音遮断性能と生活実感の表現についても，1 つの性能であるが検討することができた。

In this paper, a questionnaire survey was carried out on residents living in a real building with Li, Fmax, r, H(1)-60 by the car-tire, mainly on their living experience. At the same time, the rubber ball and the tapping machine were evaluated and the results of the questionnaire survey were analyzed. The results showed that the degree of problems with sound insulation performance, when 'problematic' and 'fairly problematic' were combined, the sound from the upper floor was more significant than the sound from outside and from the neighboring floor. L-60 of the Sound Insulation Performance Standards and Design Guidelines for Buildings [Second Edition] is the expression 'well audible', which in this study showed 74.2% as a percentage of the cumulative relative frequencies. The fact that the expression with the highest relative frequency was 'well audible' suggests that the expressions in the Sound Insulation Performance Standards and Design Guidelines for Buildings [Second Edition] are appropriate for Li, Fmax, r, H(1)-60. The floor impact sound insulation performance of the rubber ball and the tapping machine, which had not been verified before, and the expression of the living experience could also be studied, although this is only one performance.

日本建築学会において集合住宅の音環境性能AIJES の策定に向けての検討が進められ、DS 作成のための概要をとりまとめた資料が公表された。その中の床衝撃音遮断性能に関する性能規準、測定方法、評価方法の骨子について、RC 系集合住宅を対象とした床衝撃音遮断性能の測定結果を用いて検討を行った。それによって、ボール衝撃源によるA 特性床衝撃音レベルのオクターブバンド合成による算出方法や、ボール衝撃源によるオクターブバンド床衝撃音レベルからタイヤ衝撃源によるL 数を推定する方法、クラスによる評価量等、床衝撃音遮断性能に関するAIJES 策定時に考慮すべき事項についての各種知見を得た。

The Architectural Institute of Japan has been working on the formulation of AIJES sound environment performance for apartment houses, and has published a document summarizing the outline for creating DS. Among them, we investigated the performance standards and outline of measurement and evaluation methods regarding floor impact sound insulation performance using the measurement results of floor impact sound insulation performance for RC apartment houses. As a result, a method for calculating the A-weighted floor impact sound level due to the ball impact source by octave band synthesis, a method for estimating the L number due to the tire impact source from the octave band floor impact sound level due to the ball impact source, an evaluation amount by class, etc. Various findings were obtained regarding matters that should be considered when formulating AIJES regarding floor impact sound isolation performance.

日本では航空機騒音の評価指標としてLdenが採用されているが，航空機騒音の測定及び評価に際して，いくつかの実務的な課題を感じている。これらの課題を解決する手段として，総合騒音に占める航空機騒音の寄与が大きい場合には，航空機騒音の評価に総合騒音を利用することが有効なのではないかと考える。本研究では．総合騒音に占める航空機騒音の寄与が大きいと考えられる成田国際空港周辺における航空機騒音の測定結果を用いて，航空機騒音の評価量と総合騒音とを比較し，総合騒音を用いた航空機騒音の評価について考察した。

In Japan, Lden has been adopted as an evaluation index for aircraft noise, but Ifeel that there are some practical issues when measuring and evaluating aircraft noise. Asa means of solving these problems, we believe that it may be effective to use total noise to evaluate aircraft noise when the contribution of aircraft noise to total noise is large. In thisstudy, using the measurement results of aircraft noise around Narita International Airport,where aircraft noise is thought to make a large contribution to the total noise, we comparedthe evaluation amount of aircraft noise with the total noise, and considered the evaluation of aircraft noise using the total noise.

EPNL，loudness，sharpness，Tonal Audibility などの評価指標を用いて，航空機騒音の音質評価を試みた．また，機種によっては着陸時に発生することがある，純音性の特異音の特徴量についての検討を行なった．以上の物理的検討を行った上で，音響心理実験により航空機騒音の音質と主観的印象の関係を検討した．最初に，2000 年代以前の航空機を含む様々な機種の実音を刺激としたSD法による実験を実施した．その結果，A 特性音圧レベルが等しい場合でも，近年の航空機の音はより肯定的に評価され，その原因としてsharpness の低下が示唆された．次に，特異音についての評価実験を行った結果，特異音が航空機騒音の聴感的な印象を悪化させているといえる結果は得られなかった．

This paper describes the results of trial calculation to examine the possibility of evaluating aircraft noise considering its sound quality, based on several indices such as EPNL, loudness, sharpness, and Tonal Audibility, and its comparative verification, including differences in aircraft generations. Furthermore, we investigate the relationship between aircraft noise's sound quality and subjective impressions. Laboratory experiments were conducted to examine how the impression of aircraft noise differs depending on sound quality. First, an experiment using the semantic differential method was performed using sounds of various aircraft models, including those from the 2000s and earlier, as stimuli. The results showed that even when the A-weighted sound pressure levels were equal, the sounds of recent aircraft were perceived more positively, suggesting that a decrease in sharpness was the cause. In addition, another experiment using the method of adjustment was conducted to examine the effect of extraordinary tonal sounds included in aircraft noises. As a result, it could not be said that the extraordinary tonal sounds negatively affected the evaluation of aircraft noise.

航空機から発生する騒音のうち，離陸時はエンジン騒音が支配的であるが，着陸時は高揚力装置や着陸装置などから発生する空力騒音の寄与が大きい。従って，着陸経路周辺地域の騒音低減対策を実施するためには，騒音発生部位別に飛行状態を考慮した詳細な予測計算が可能となる騒音予測モデルが必要である。そこで筆者らは，直径30 m におよぶ大型マイクロホンアレイを用いて計測する音源分布図から部位別に作成する音源モデルを基盤とする騒音予測フレームワークJ-FRAIN（Japan-FRAmework for AIrcraft Noise simulation）を開発した。本報では，J-FRAIN の概要について紹介する。

Among noises generated by aircraft components, noise generated by enginesdominates when aircraft take off. In contrast, aerodynamic noise generated by high-lift devices,landing gears, and so on dominates when aircraft approach airports. In order to make noise countermeasures in the vicinity of the landing approach path, a noise prediction model that enables detailed and accurate predictions for each noise-generating component considering flight conditions is needed. In such a situation, the authors newly developed a noisesimulation framework named ‘J-FRAIN’, an acronym for Japan-FRAmerowk for AIrcraftNoise simulation, which has the component-wise sound source model derived from acoustic maps measured with a large aperture microphone array of 30 m in diameter as a core feature.An overview of J-FRAIN is summarized in this paper.

着陸後に強力なスラストリバーサーを使用すると、空港周辺に騒音の影響を及ぼすことが多い。スラストリバーサーの使用は、必ずしも着陸操作の必須条件ではないが、安全性をより確実にするための手段でもある。そのため、リバース推力の大きさや、リバーサーが使用される滑走路の区間は様々である。我々は、滑走路側のいくつかの地点で測定した騒音から、リバース・スラストの利用率と強さを推定する方法を検討し、前報で報告した。本報告書では、この比較的簡便な調査方法を用いて調べた日本の多くの空港におけるリバース・スラストの運用状況を分析した結果について述べる。

The use of powerful thrust reversers after landing often results in a noise impact on the area of surrounding the airport. The use of thrust reversers, while not necessarily a prerequisite for landing maneuvers, is sometimes a significant means of ensuring more safety for the pilot. For this reason, the magnitude of the thrust reversers, and the segment of the runway in which the reversers are used, vary widely. We have established a method to determination of the utilization and the strength of reverse thrust from noise measurements taken at several stations along the runway side. This report also describes an analysis of the results of the operational conditions of thrust reversers at a multitude of Japanese airports that were examined using the methodology.

航空機騒音に対する空港周辺の環境対策は、国際民間航空機関（ICAO）で定めるバランスドアプローチという基本理念のもとに、各国・各空港でそれぞれに最も適切な方策を用いることになっているが、評価指標や基準が異なるだけでなく、対応策も異なっている。本報告では、日本及び海外主要空港の航空機騒音評価と航空機騒音対策をレビューし、評価や対策の考え方やその温度差を考察することにした。

The environmental countermeasures against aircraft noise in the vicinity of the airport is based on the principle of a balanced approach, as defined by the International Civil Aviation Organization (ICAO), and each country and airport is supposed to use the most appropriate measures, but not only are the evaluation indices and the criteria used differently, but also the countermeasures are also different. In this report, aircraft noise evaluation and airport noise countermeasures at major airports in Japan and other countries are reviewed, and differences in evaluations and countermeasures between these airports are also discussed.

航空機騒音の予測においては，航空機の騒音レベルと距離の関係を示したNPD（Noise-Power-Distance）を用いた計算が広く行われている．この予測方法は，簡便であるという点で有用であるが，NPD に基づき有限長の線音源を求める際に，音源の指向性等に関する仮定を要する．そこで，本研究では，この仮定に基づき導出される有限長線音源の音響特性について考察し，NPD を用いず航空機騒音を点音源として扱い，レベル変動に関しても予測可能なモデルであるsonAIR を用いた場合について，航空機騒音の予測を試みた．

Noise-Power-Distance (NPD), which gives the relationship between aircraft noise level and distance, is widely used in aircraft noise prediction. This method is useful in that it is simple, but it implicitly assumes the directivity of the sound source, and a finite-length line source based on NPD would have directivity. In this study, the acoustic characteristics of finite-length line sources derived on the basis of these assumptions are investigated and aircraft noise is predicted using sonAIR, a model that treats aircraft noise as a point source without using NPD and can also predict fluctuations in sound levels.

鉄道からの騒音・振動は，沿線の居住者の日常生活に影響を及ぼしており，多くの既往研究において，騒音，振動それぞれの曝露量と住民反応との関係が報告されている。筆者らは，鉄道沿線で実施された騒音・振動を対象とした社会調査から得られた個票データ（在来線鉄道：5 データセット・新幹線鉄道：7 データセット）の二次分析を行い，鉄道騒音・振動の複合曝露によるアノイアンスへの影響を検証した。具体的には，構造方程式モデリングの一手法である多母集団同時分析を鉄道種別（在来線鉄道と新幹線鉄道の2 種別）に適用し，鉄道からの騒音，振動それぞれの曝露量と両者の交互作用項によるアノイアンスへの影響を比較した。さらに，鉄道種別を区別しないで一つにまとめ，騒音と振動それぞれの曝露量からアノイアンスへの影響を定量的に把握した。

Railway-induced noise and vibrations affect the daily lives of people living along railway lines. Lots of previous studies have focued on the relationship between exposure to noise or vibration and community reponse to corresponding exposure. Using individual data (Conventional railway: 5 data sets, Shinkansen railway: 7 data sets) derived from social surveys on communty response to noise and vibration along railway lines, we examined the effects of combined exposure to railway noise and vibration on annoyance. Specifically, applying multi-group mean and covariance structure analysis, a method of structural equation modelling, to the individual data, we quantitatively compared the effects of respective exposure to noise and vibration from railway and interaction terms between the two exposures on annoyance between railway categories (conventinal and Shinkansen railways). Furthermore, combining the railway categories into one, we quantified the effects of the respective exposure to noise and vibration on the annoyance.

製品音の大きさは，一般に規格などで定められた測定点における応答(A 特性音圧レベル) で評価される。しかし，このA 特性音圧レベルと，人の両耳聴取における応答(両耳ラウドネス) は相違する場合がある。本報では，両耳ラウドネスに基づく音響指標を用いた製品音の評価方法とその評価結果について述べる。対象製品はスティック掃除機とし，掃除機の使用者頭部中心および側方に設けた測定点で得た掃除機運転音の応答に対して，前述の音響指標による評価を実施した。その結果，従来評価と比べて運転音が大きな周波数や主たる音源が変化する場合があることを確認した。この結果から，本評価方法により従来評価では困難であった主観的な音の大きさを考慮した音響設計を実現できる可能性が示唆された。

The loudness of a product noise is generally evaluated by theresponse (A-weighted sound pressure level, A-SPL) at a measurement point defined by a standard. However, the A-SPL and the human binaural response(binaural loudness) may differ. In this paper, we describe the results of a study on the evaluation method of product noise using an acoustic index based onbinaural loudness. The target product was a stick vacuum cleaner, and we evaluated the response of the cleaner’s operating noise at the center of theuser’s head and at a point on the side of the cleaner using the acoustic index. As a result, there were cases in which the operating noise level changed at a higher frequency, or the primary sound source changed compared to the conventional evaluation. These results suggest that this evaluation method may realize an acoustic design that considers subjective loudness, which has been difficult with conventional evaluation.

現在，建物の高さ情報に関して，国内で広範囲に利用可能なデータは見受けられない. そのため，騒音予測においては建物高さを一定と仮定して計算されることが多い．しかし，正確性に影響が及ぶ可能性がある．そこで，本研究では3 次元点群データを用いて，騒音予測に用いる建物高さの推定を試みた．3 次元点群データが公表されている静岡県内を研究対象とした．点群高さの中央値を用いることにより，効率的な建物高さの推定が可能であった．ただし，2D 建形と3 次元点群データの不整合により，建物高さの推定値が低くなることがあった．今後，3 次元点群データの活用をさらに進め，より精度の高い建物高さの推定が望まれる.

Currently, there is no widely available data on building heights in Japan. As a result, noise predictions are often calculated assuming a constant building height, which may affect the accuracy of the prediction. In this study, 3D point cloud data is used to estimate building heights for noise prediction. These data have been published and are available for estimating building geometries in noise prediction. The study area was in Shizuoka Prefecture, where 3D point cloud data is publicly available. Efficient estimation of building heights was achieved by using the median of the point cloud heights. However, inconsistencies

騒音予測においては，地形や障害物等の地理空間情報を正確に把握する必要がある。とりわけ，沿道に設置される遮音壁を騒音予測に反映することが重要である。本研究では，遮音壁の情報を広域にわたって取得して騒音予測に反映する手法として，近年整備が進む3 次元点群データを用いた手法を提案する。道路中心線の情報をもとに，3 次元点群を道路の垂直断面上に投影し，回帰，ピーク抽出，補間，等によって遮音壁およびそれが設置される道路の鉛直構造に関する3 次元モデル化を試みた。静岡県内の国道のある区間を対象として適用したところ，盛土・切土・高架等がモデル化され，設計図面とよく一致する遮音壁高さが得られた。今後，騒音予測への活用が期待される。

Accurate information on geospatial information, such as topography and obstructions, is required for noise prediction. In particular, it is important to reflect the information of noise barriers installed along the roadside. In this study, the author proposes a method to estimate geospatial information on noise barriers using 3D point cloud data, which has been widely used in recent years. Based on the information of the road centerline, the 3D point cloud was projected onto the vertical section of the road. Noise barriers and the vertical structure of the road were then modeled using regression analysis, peak extraction and interpolation. Inthe study area, a section of a national road in Shizuoka Prefecture, the elevation, embankment and cut were modeled, and the height of the noise barriers was estimated in good agreement with the design drawings. This model is promising to be used for noise prediction in the future.

系パラメータを提案することを目的に，クリーンルームで発話実験を実施した．発話時の音環境（A 特性音圧レベル）と発話レベルの関係式を得るために，非線形回帰分析を行った．また，飛沫量の発生頻度はGamma-Poisson 分布に従うことを示し，一般化線形混合モデルにより飛沫放出量の予測手法を検討した．さらに，発話レベルと飛沫量の関係を把握するためにポアソン回帰分析を行い，発話レベルとエアロゾル及び飛沫放出量の関係式を得た．得られたそれぞれの関係式を用いて，発話レベルを媒介変数としたA 特性音圧レベルによる飛沫放出量の予測計算法を導いた．

The speech experiment was conducted in a clean room with the aim of proposing droplet generation system parameters that consider human speech characteristics in the infection probability prediction model. Non-linear regression analysis was used to obtain an equation relating the sound environment during speech (A-weighted sound pressure level) to speech level. As the frequency of the droplet volume follows a Gamma-Poisson probability, a generalized linear mixed model was used to investigate a prediction model for droplet emission. Furthermore, Poisson regression analysis was done to obtain an equation relating speech level to aerosol and droplet emissions. Those were used to derive a method for calculating the number of droplets by A-weighted sound pressure level making use of speech level as a mediating variable.

「学会発表にふさわしいタイマー音」をデザインし，Inter-Noise 2023 て?実用すること，さらにはそのデザイン実践を通じて得た知見を関係学会て?共有することを目的として，有志によるデザインプロジェクトを実施した。まず，既存ベル音の評価や分析によってデザインアプローチを確定させ，試作音の聴取実験による評価を経て最終サウンドを確定させた。実会場て?使用の上て?，参加者へのアンケート調査を行い，概ね好評を得た。

A design project was conducted by the authors with the aim of designing “timer sound suitable for conference presentations.” Specifically, the design approach was determined through the evaluation and analysis of existing bell sounds, and the final sound was determined through subjective evaluation experiments of prototype sounds. A questionnaire survey was also conducted with the participants at the venue of Inter-Noise 2023. The sound was generally well received.

2024年3 月1 日に開催したADC 設立4 周年記念の実験的イベントについて紹介する。響き過ぎて言葉の明瞭度が低いレンタルスペースを，４社による吸音対策で１日だけ適度な響きの空間に変身させた上で，講演・トークショー・ミニコンサートを実施した。さらに最後は取り付けた吸音材を全て取り外し，音の聞こえ方がどう変化するかを参加者全員で体験した。

We will introduce an experimental event held on March 1, 2024 to commemorate the 4th anniversary of ADC's founding. A rental space that reverberated too much and reduced speech intelligibility was transformed into a space with moderate reverberation for one day using sound-absorbing measures by four companies, and lectures, talk shows, and mini-concerts were held there. At the end of the event, all the installed sound-absorbing materials were removed, and all participants experienced how the way sound was heard changed.

共同住宅では，設計時にスラブ素面の重量床衝撃音レベルの予測計算を行い，適切なスラブ厚や仕様を設定する。本報では，設計時と竣工時の床衝撃音遮断性能にについて検討した。軽量床衝撃音遮断性能は，床仕上げが乾式二重床の場合に比べ直貼り防音フローリングではL 数の平均値は小さかったが，ばらつきが大きかった。タイヤの重量床衝撃音遮断性能は，設計目標値をL 数50とする場合が多く，性能の低下が小さい直貼りフローリング・スラブ素面の値が小さくなる傾向を示していた。ボールの重量床衝撃音遮断性能はタイヤの場合とは異なり，直貼り防音フローリングの値のほうが大きくなる傾向を示していた。

In multi-family housings, the predictive value of the heavy-weight floor impact sound level on the slab surface is performed at the time of design, and the appropriate slab thickness and specifications are set. In this paper, the floor impact sound insulation at the time of design and at the time of completion of construction is examined. The light-weight floor impact sound insulation of directly-attached soundproof flooring showed a smaller average value of L-number than that of dry double-layered flooring, but there was a large variation in L-number. The heavy-weight floor impact sound insulation of tires tended to have smaller values for direct-attached flooring and bare slab surfaces, where the decrease in performance was smaller, because the design target value of L-number 50 was often set. In contrast to the case of the tires, the sound insulation of the ball tended to be larger than that of the direct-attached soundproof flooring.

本研究では，防振材による設置共振の誤差低減に関する研究を継続してきた。本研究の提案は，床仕上げ材上に防振材を設置し，その上に振動ピックアップを載せて測定を行い，その結果から，既知の防振材単体の振動伝達率を除することで，床仕上げ材下部の床構造の振動加速度を推定する方法である。これまでの振動源は，加振器による正弦波，又は，一定の衝撃力特性を有するゴムボール落下であった。本稿では，鉄道振動を対象として実住宅において実験的検討を行った。その結果，本研究で提案している防振材の振動伝達率を利用した推定値と実測値がほぼ同様な結果を示した。本稿の範囲では，各周波数帯域での設置共振による誤差が2 dB 以内であった。

This study has continued research on the reduction of contact resonance errors by vibration control rubber. Studies have been conducted on carpets and tatami mat floors. Vertical and horizontal studies have also been conducted. The proposed method is to install a vibration control rubber on top of the floor finish material, place a vibration pickup on top of the vibration control rubber, make measurements, and then estimate the vibration acceleration of the floor structure below the floor finish material by dividing the results by the known vibration transmission coefficient of the vibration control rubber alone. The vibration source has so far been a sine wave from a shaker or a rubber ball drop with a certain impact force characteristic. In this paper, an experimental study of railroad vibration was conducted in a real house. In this paper, only the vertical direction is considered. As a result, the estimated value using the vibration transmission coefficient of the vibration control rubber proposed in this study and the measured value showed almost similar results. In the range of this paper, the error due to contact resonance in each frequency band was within 2 dB."

カーボンニュートラル社会に向けて，電動車が主流となる将来の道路騒音を考察した。まず，道路交通騒音の状況について，過去から現在までの推移を整理した。沿道騒音改善のため，自動車単体騒音の規制強化が行われてきたが，それが十分機能しなかったことを示した。そこで電動車も対象となる自動車単体騒音の規制として，国連による国際基準が導入されたことを示した。この国際基準の規制値とASJ RTN-Model 2023 の関係を示し，将来の沿道騒音の改善について考察を行った。次に，地方公共団体による電動車導入推進の取り組みと，電動車の走行騒音にボトルネックとなるタイヤ/路面騒音対策の技術動向とを紹介した。最後に，現実的な自動車騒音問題に対処するため，国内外で行われているさまざまな対応策を紹介した。

How will road traffic noise change in a carbon-neutral society where electric vehicles become mainstream? To know this, we first summarized the trends of road traffic noise from the past to the present. We found that stricter regulations on vehicle noise have been implemented, but it has been shown that these measures have not been effective enough. This led to the introduction of international standards by the United Nations to regulate the noise limit of individual vehicles, which also applies to electric vehicles. We showed the relationship between the regulatory values of this international standard and ASJ RTN-Model 2023 and considered future roadside noise improvements. Furthermore, efforts by local governments to promote the introduction of electric vehicles, and technological trends in measures against tire/road noise, which is a bottleneck in the running noise of electric vehicles are presented. Finally, various countermeasures that are being taken both domestically and internationally to deal with realistic automobile noise problems are introduced.

路交通騒音予測モデルであるASJ RTN-Model では，平行に設置された二重遮音壁の二回回折による伝搬計算方法が示されているが，遮音壁間の地表面の影響は考慮されていない．本報では，3 次元波動数値解析によりその影響を把握すると共に，ASJ RTN-Model に基づき地表面の影響を簡便に考慮する実用計算モデルを提案・検証した．今回の検討対象で，かつ道路交通騒音を前提とした場合，地表面の影響は小さく2 dB 以下に止まった．提案した実用計算モデルの適用により，従来のASJ RTN-Model と比べて波動数値解析結果との差が小さくなることを確認した．

The ASJ RTN-Model, a road traffic noise prediction model, presents a method for calculating noise propagation through double diffraction between parallel noise barriers, but it does not account for the ground surface reflections between the barriers. This study uses three-dimensional wave-based numerical analysis to assess this influence and proposes a simplified calculation model to include the ground surface influence in the ASJ RTNModel. Numerical analysis results show that, when considering road traffic noise, the ground surface influence between walls is remaining below 2 dB. The proposed calculation model also reduces the discrepancy between the ASJ RTN-Model and wave-based numerical analysis results compared to direct application of the ASJ RTN-Model.

騒音の空間性に着目し、生活環境に身近である交通騒音を想定したうるささに関する心理評価実験を行った。次に、より現実的な騒音の入射状況を考慮して、方向条件を8 条件に増やして実験を行った。その結果、今回の条件では、特定の方向から騒音にさらされる場合よりも実験参加者の前後左右から音が聞こえてくる4ch 平面条件の方がうるさく感じられる傾向が見られた。その後頭部の物理的影響を確認するため、ダミーヘッドマイクロホンを用いた計測を行った。その結果耳に入力されるA 特性音圧レベルが等しい場合でも、方向条件によってうるささ感が異なる傾向が示唆された。

A psychological evaluation experiment on the noisiness of traffic noise focusing on the directionality of noise is conducted. Next, the experiment was conducted by increasing the number of directional cases to eight to consider more realistic noise incident conditions. The results showed that, under these conditions, when exposed to noise from a specific direction, the 4ch condition in which sound is heard from the front, back, left, and right of the participants tended to be perceived as noisier than the 1ch condition. After that, to confirm the physical influence of the occipital area, we took measurements using a dummy head microphone. The results suggest that even when the A-weighted sound pressure level input to the ear is the same, the tendency for the noisiness to differ depending on the directional condition.

音線法及びWE-FDTD 法を用いた聴取性指標の算出が提案されている。しかしながら，模擬都市街区における境界面の音響特性が聴取性に与える影響の系統的な検討や両手法の比較は行われていない。そこで本研究では，WEFDFD法を用いて，都市街区において境界面の音響特性が聴取性に与える影響を検討する。また，音線法と同様の条件で聴取性を算出する。結果は，建物壁面の音響特性の方が地表面の音響特性より，聴取性に与える影響が大きい。これは，伝搬音が建物壁面間で反射する回数が多いためである。音線法との比較では，音源高さが低い場合，聴取性が小さくなる。音源高さが高い場合，音源から遠い場所で聴取性が大きくなる。これらは，回折と反射の組合せによる。

The calculation of speech intelligibility index using the sound ray-tracing and WE-FDTD methods had been proposed before. However, there has been no systematic study of the effect of boundary surface acoustic properties on speech intelligibility in an idealized urban area or comparison of the two methods. In this study, the WE-FDFD method is used to investigate the effect of application of boundary surface acoustic properties on speech intelligibility in an urban area. The speech intelligibility is calculated under the same conditions as for the sound ray-tracing method. The results show that the acoustic properties of the building walls have a greater influence on speech intelligibility than those of the ground surface. In comparison with the sound ray-tracing method, speech intelligibility becomes smaller when the sound source height is low. Speech intelligibility is greater at locations far from the sound source when the sound source height is high. These are due to a combination of diffraction and reflection.

交通機関からの騒音や振動は沿線の居住者の生活に影響を及ぼしており，その活動の妨害感が騒音や振動のアノイアンスへ影響することが既往研究において報告されている。筆者らは，騒音と振動が複合的に妨害感や不快感へ影響する程度を定量的に捉えようと実験的に検討してきた。本稿では，鉛直方向と水平方向（横）の2 方向の振動に加えて音刺激が組み合わさった場合の計算作業時の妨害感や不快感など心理的な影響を検討した実験結果を報告する。総合的な不快感と妨害感は，条件範囲が限られるが，共通の水平振動でも鉛直振動が大きくなると反応が高くなり，さらに音刺激が大きくなるとさらに反応が高くなる傾向がみられた。音刺激が70dB（LA,Smax）の条件では振動刺激の組み合わせによる反応の規則性は見られなかった。水平振動と鉛直振動の曝露量を合成して心理反応との対応を検討したが，今後のさらなる分析が必要である。

Noise and vibration from transportation systems affect daily activities, and prior researchs have reported that the disturbance of these activities influences the annoyance caused by noise and vibration. The authors have conducted experimental studies to quantitatively understand the extent to which noise and vibration have a combined effect on disturbance and discomfort. This paper reports the experimental results examining the psychological effects, such as disturbance and discomfort, when both vertical and lateral vibrations are combined with sound stimuli during calculation tasks. Although the overall discomfort and disturbance were measured in limited conditions, it was observed that even with the same lateral vibration, an increase in vertical vibration led to higher responses, and further increases in sound stimuli also resulted in heightened responses. In the condition with a sound stimulus of 70 dB (LA,Smax), no clear pattern was observed in the responses due to the combination of vibration stimuli. While the relationship between combined exposure levels of lateral and vertical vibrations and psychological responses were examined, further analysis is needed to build better models.

欧州連合指令2002/49/EC (環境騒音指令) の発令に至る経緯の一つとして，欧州委員会による政策提案書のFuture noise policy が知られる。また，発令後の当該指令の履行状況への改善の努力が知られる。一方，当該提案書以外の経緯及び具体的な履行状況の知見は乏しい。そこで，欧州連合及び関連諸機関の文書，並びにデータベースを調査した。その結果，当該提案書は経済協力開発機構の騒音に関する現状認識及び見通しを継承していること，補完性原則によって騒音マップ及び行動計画の作成が加盟国に任されていること，国内法化義務不履行に関する違反手続事例が多いこと，訴訟事例は全てEND の不良適用によることが判った。

Future noise policy, a policy proposal by the European Commission, is known as one of the key documents that led to the legislation of European Union Directive 2002/49/EC, called the Environmental Noise Directive. Also, the efforts to improve the implementation of the Directive after its legislation are known. However, there is little information on the history of the legislative process other than the proposal and specific implementation status. Therefore, documents and databases of the European Union and related organizations were investigated. The results found that the proposal inherits the current situation and outlook of the Organization for Economic Co-operation and Development regarding noise, that the principle of subsidiarity leaves the preparation of noise maps and action plans to the Member States, that most of the cases of infringement procedure are due to non-fulfillment of transposition to national laws, and that all court cases are due to bad application.

本研究では，風景を景観と音環境から構成されるものと捉え，思考発話法を用いて，風景の評価語を抽出することを試みた。同手法により，景観と音環境それぞれについて評価語を抽出した。その評価語を基にSD 尺度を作成し，風景の印象評価実験を実施した結果，風景は，田舎的風景と都会的風景の2 グループに分類された。続いて，因子分析を実施したところ，3 つの因子が抽出された。特に，第1 因子においては，音環境の評価語9 項目の内8 項目がこの因子と最も高い因子負荷量をもっており，音響学的観点から，風景評価における音環境の重要性が示唆された。また，因子得点を基に都会的風景と田舎的風景の特徴について検討を行ったところ，発展している都会とそうでない田舎との間で，田舎の方が都会よりも魅力的な印象を受けるという傾向が見られた。

In this study, the scenery was defined as the combination of landscape and acoustic environment. Think-aloud protocols (TAPs) were used to extract evaluative words of landscape and acoustic environment, individually. The experiment was conducted to evaluate the sceneries with semantic differential (SD) scales of evaluative words. It was shown that the sceneries were classified as the rustic scenery or the urban scenery. Furthermore, as the results of factor analysis, three factors were extracted and eight of nine observed variables in acoustic environment had the highest correlation with the first factor. It means that acoustic environment could have an important effect on scenery evaluation. The scatter plot of factor scores showed that the rustic scenery was more attractive than the urban scenery.

共同住宅等の隣接住戸間の遮音設計を行う場合，界壁の遮音性能に加え，窓などの開口部からの廻り込みや外壁などを伝搬する固体音（以下，側路固体音と称す）などの側路伝搬音の影響を考慮する必要がある。そこで，木造軸組工法を対象として，隣戸間遮音性能に関する実験的検討を行った。まず，木造軸組界壁を対象に音響透過損失を測定した。続いて，界壁および外壁を組み合わせた実験室を製作し，外壁などによる側路固体音の影響の把握を試みた。更に，外壁を経由する側路固体音の低減対策について検討した。

When designing sound insulation between adjacent units in apartment buildings, etc., it is necessary to consider the effects of flanking sound, such as sound coming around from openings such as windows and structure-borne sound propagating through external walls (hereinafter called the flanking structure-borne sound), in addition to the sound insulation performance of parting walls. Therefore, we conducted an experimental study on the sound insulation performance between rooms separated by the wooden frame construction. First, we measured the sound reduction index of a wooden frame parting wall. Next, a laboratory was constructed combining parting walls and external walls, and an attempt was made to grasp the effects of flanking structure-borne sound by external walls. Furthermore, we investigated measures to reduce the flanking structure-borne sound that passes through the external walls.

建設工事作業に伴い発生する地盤振動と，それの幅と深さの異なる種々の空溝による低減効果を確認する実験を行った。その結果，以下が確認された。すなわち，１）バックホウによる打撃および走行の振動特性は，鉛直方向の振動レベルが大きく，31.5Hz 帯域付近の振動加速度レベルが大きい。２）地盤の距離減衰傾向は，周波数が高くなるにつれて減衰量が大きい。３）実験した形状の空溝により振動レベルは2～8dB 低減され，空溝の幅よりも深さの方が振動の低減効果が高い。４）空溝幅による低減効果は，バックホウ打撃時において31.5～63Hz 付近の帯域で約5dB の低減効果が見られた。

Experiment studies were conducted to investigate the ground vibrations that mobilizes during construction work and the reduction effect of various trenches with different widths and depths. As a result, the following was confirmed: 1) The vibration characteristics of the impact and move of the backhoe are high in the vertical vibration level and high in the vibration acceleration level around the 31.5 Hz band. 2) The tendency of ground vibration to attenuation over distance is such that the higher the frequency, the greater the attenuation. 3) The trench shape investigated reduced vibration levels by 2-8 dB, with trench depth having a greater effect on reducing vibration than trench width. 4) The trench width reduced vibration around 5 dB in the 31.5-63 Hz band during backhoe strikes.

本稿では、地盤改良を用いた振動対策方法WIB 工法を紹介する。先ずWIB 工法を用いてこれまで行った振動対策の内、TMD も用いて総合的に建物振動対策を行った高速道路高架橋横事務所ビル建替えの実例を紹介する。次にWIB 工法の振動低減原理に触れ、その効果をコンピューターシミュレーションも交えて検証する。

WIB (Wave Impeding Barrier), a vibration mitigation method using ground improvement techniques is presented in this paper. First, a real case that WIB was implemented for a new office building adjacent a highway viaduct is shown. Next, theoretical background of WIB is discussed with some results from computational analyses.

某施設にて，振動試験機による振動問題が試験室上階で発生するとのことから，問題解決のために振動計測を行った．当初，振動伝搬経路は躯体伝搬によるものと推定し計測を実施した．しかし、振動伝搬を測定し，各部材の固有振動数，距離減衰等の項目を考慮した場合においても，躯体を伝搬し試験室上階で問題が発生している可能性は低いと考えた．そこで他の振動伝搬経路として空気伝搬を介すること推定し，算出により可能性を推察した．結果，試験機を設置した部屋の固有振動モードの周波数と試験室上階の床振動の周波数が近いことが分かり，振動伝搬経路に空気伝搬を介する可能性を示唆した。

A factory received reports of vibration problems on upper floors, allegedly causedby vibration testing machines. To address these concerns, a vibration measurement survey was conducted. Initially, it was hypothesized that vibrations transfer paths in the building structure. To verify this, based on the measurement results, the natural frequency and amplitude ratio of each building material were analyzed. It was determined that transfer paths in the air structural from the machine to upper floors was unlikely. As an alternative, transfer paths in the air were considered as a potential vibration transfer path. Therefore, transfer paths in the air propagation were presumed as another propagation path, and its possibility was inferred through calculations. As a result, it was found that the natural vibration mode frequency of the room in which the test machine was installed was close to the vibration frequency of the floor above the test machine, indicating the possibility that transfer paths in the air propagation could be a vibration transfer path.

Modelling traffic noise propagation behind buildings has been a challenging issue for environmental noise assessment. As a solution, the ASJ RTN-Model proposes a straightforward while powerful method to quantify the effect of road traffic noise reduction by buildings, which is characterized as the insertion loss. Despite its effectiveness, current prediction model has several limitations: first, the noise source can only be positioned at the height of ground surface; and second, only one type of noise source is considered with a fixed frequency characteristic. To further extend its range of application, in this work, we investigate methods to adjust current prediction model by maintaining the main structure of prediction equations while re-determining the parameters (variants and constants) at higher positions of noise source and different frequency bands. We examine the effectiveness of our method by comparing the calculation results with experimental ones obtained from scale model experiments, and further explore the possibilities of establishing prediction equations based on a certain frequency characteristic of noise source.

著者らは，低周波数成分を含む自動車交通騒音を対象として，同騒音に含まれる低周波数成分の有無を基本パラメータとした主観評価実験を行った．次に，この実験から得られたデータに構造方程式モデリングを適用し，自動車交通騒音に対する不快感の評価構造モデルを構築した．本稿では，被検者の個人属性として騒音感受性の違いを考慮し，騒音感受性を低感受性群と高感受性群の2 群に分け，構造方程式モデリングを適用し，多母集団同時分析を行なった．さらに，分析の結果から，等価騒音レベルや低周波数成分の有無の不快感評価への影響を検討するとともに，騒音感受性による評価構造の違いを考察した．

The authors conducted a subjective evaluation experiment on road traffic noise containing low-frequency components, using the presence or absence of low-frequency components in the noise as a basic parameter. Next, we applied structural equation modeling to the data obtained from this experiment to construct a structural model for evaluating discomfort from road traffic noise. In this paper, we considered the difference of noise sensitivity as the personal attributes of the examinees, and divided the noise sensitivity into two groups, low-sensitivity group and high-sensitivity group, and applied structural equation modeling to perform simultaneous multi-population analysis. Furthermore, from the results of our analysis, we examined the influence of the equivalent noise level and the presence or absence of low-frequency components on the evaluation of discomfort, and we considered the differences in the evaluation structure depending on noise sensitivity.

ポーラスアスファルト舗装の騒音低減効果の持続年数は5～10 年であるが，名古屋市内には施工後10?20 年経過しているポーラスアスファルト舗装が点在する。本研究では，ポーラスアスファルト舗装の打ち替え前後の状態で騒音測定を行い，打ち替え前の状態の道路交通騒音低減効果は低下していることを確認した。その要因は，ポーラスアスファルト舗装の舗装内部の通気性の低下と路面の硬さの増加だと推定した。さらに，路面の硬さの増加が道路交通騒音低減効果を低下させることを調べるため，ボール落下試験を実施した。その結果，打ち替え前よりも打ち替え後の方が路面の硬さおよび衝撃音が小さくならず，路面の硬さの増加による道路交通騒音低減効果の低下を明らかにできなかった。

Noise reduction effect of porous asphalt pavement is kept from 5 to 10 years, but the pavement built from 10 to 20 years ago is scattered about Nagoya city. In this study, road traffic noise was measured before and after replacement of porous asphalt pavement, and it was confirmed that road traffic noise reduction effect before replacement was decreased. It was estimated that the factor was decrease of porosity and increase of road surface stiffness of porous asphalt pavement. In addition, the ball drop test was done because it was investigated that increase of road surface decreased road traffic noise reduction effect. As a result, road surface stiffness and impact noise of porous asphalt pavement after replacement was not lower than those before replacement, and decrease of road traffic noise effect by increase of road surface stiffness was not revealed.

道路交通振動の地盤から建物基礎への入力機構の解明に資するため，軟弱地盤上に建つ建物を一事例として，振動実測とシミュレーション解析による検討をおこなった。その結果，当該サイトにおいては，建物基礎が地盤の水平方向振動に追随して並進するのみではなく，地盤の鉛直方向振動の位相差に追随してロッキングもしていることがわかった。このようなケースでは，単に地盤の水平方向加速度波形を建物基礎に入力するだけの方法では，建物応答を過少に予測してしまうことになる。建物基礎の並進とロッキングの双方を考慮することで，応答予測結果は建物3 階中央の水平方向の実測記録を良好に再現できた。

In order to contribute to the clarification of the input mechanism of road traffic vibration from the ground to the building foundation, a vibration measurement and simulation analysis were conducted on a building built on soft ground as a case study. As a result, it was found that the building foundation not only translates according to the horizontal vibration of the ground, but also vibrates according to the phase difference of the vertical vibration of the ground. In such cases, simply inputting the horizontal acceleration waveform of the ground into the building foundation will result in an underestimation of the building response. By considering both the translation and the rocking of the building foundation, the response prediction results were able to well reproduce the measured horizontal record at the center of the third floor of the building.

交通騒音など時間変動のある騒音に対する聴感印象を調べ，騒音評価指標との対応関係を検討することを目的として聴感評価実験を実施した。試験音は，道路交通騒音，航空機騒音，鉄道騒音，風車騒音の実録音をもとに編集した5 分間の試験音で，試験音を聞きながら時々刻々のうるささを評価する連続判断と，試験音全体のうるささを評価する全体判断の2 つを実施した。評価指標としては，等価騒音レベルに加えてラウドネスレベル（ISO532-2）の時間平均値の2 種類を用いた。結果として，等価騒音レベルとラウドネスレベルはともに騒音のうるささの全体判断とよい対応を示したが，試験音によっては等価騒音レベルとラウドネスレベルの時間平均値が乖離する場合があった。

A subjective evaluation experiment was conducted to investigate the auditory impressions of time-varying noises, such as traffic noise, and to examine their correspondence with noise evaluation indices. The test sounds consisted of 5-minute edited recordings based on actual recordings of road traffic noise, aircraft noise, railway noise, and wind turbine noise. Two evaluation methods were employed: continuous judgment, where participants rated the moment-to-moment noisiness while listening to the test sounds, and overall judgment, where participants assessed the overall noisiness of the test sounds. As evaluation indices, two measures were used: the equivalent continuous sound level (LAeq) and the time-averaged loudness level (ISO 532-2). The results showed that both LAeq and the time-averaged loudness level correlated well with the overall annoyance judgments of the noise.

航空機騒音の自動監視において時々刻々観測される音のレベル、到来方向、周波数スペクトルの時系列から騒音イベントを抽出してその音源を同定し、航空機騒音ならば機種を識別し、飛行経路を推定する手法を研究してきたが、最近は騒音イベント区間だけでなく、観測される環境騒音全体に監視対象を広げ、観測点の音風景の推移として把握しようとする音響情景分析の手法へと研究の対象を拡大している。本稿ではそうした研究の経緯を、主に意義や有効性の視点から簡単に振り返り、残された課題の解決やさらなる展開への見通しを述べる。

This paper briefly reviews our study on the method for identifying sound sources of noise events, extracted from the time series of level fluctuating environmental sound, and in case of aircraft flyover noise events identifying aircraft types and flight paths, using information of the instantaneous three-dimensional sound arrival directions and power spectra of the sound observed at the unattended noise monitoring point. In addition, in recent years, our research has been extended to include the entire environmental sound occurring at the observation point, as targets being analyzed, and to develop a method of acoustic scene analysis which intends to grasp the sound field consisting of not only noise events but also the other entire environmental sound, and to understand it as the changing soundscape at the observation point. This paper briefly reviews the history of such research, mainly from the viewpoints of significance and validity of the methodology and discusses the remaining issues and prospects for further development.

航空機騒音の自動監視においては観測する音のレベル、到来方向、周波数スペクトルのデータを活用して騒音イベントを検出し、音源識別を行っている。著者らはそのデータの範囲を騒音イベントの区間以外まで広げ、環境騒音全体での音風景の推移を把握する音響情景分析の手法を研究している。音風景を構成する各種音源の性状を考察するには事前情報として周辺の飛行経路や道路、建物などの配置や音源としての作動状況を把握する必要があるが、時間とともに変化するため、常に準備できるわけではない。そこで音のスペクトルに着目して事前情報無しと想定し、教師無し学習の一手法であるクラスタリングの手法により適切な音源の数と分類を効率的に推定する方法を検討している。本報告はその概要を示す。

In automatic aircraft noise monitoring, noise events are detected and sound sources are identified by using data on the observed sound level, direction of arrival, and frequency spectrum. The authors are researching acoustic scene analysis methods that expand the scope of data to include areas other than noise event sections and grasp the transition of the soundscape in the entire environmental noise. To consider the characteristics of various sound sources that make up the soundscape, it is necessary to understand the layout of surrounding flight paths, roads, buildings, etc. and their operating status as sound sources as prior information. However, since this changes over time, it is not always possible to prepare. Therefore, focusing on the sound spectrum and assuming no prior information, we are considering a method to efficiently estimate the appropriate number and classification of sound sources using a clustering method, a method of unsupervised learning. This report provides an overview.