著者

Yun-Fan Hwang Hideo Suzuki

出版者

一般社団法人 日本音響学会

雑誌

Acoustical Science and Technology (ISSN:13463969)

巻号頁・発行日

vol.37, no.3, pp.115-122, 2016-05-01 (Released:2016-05-01)

参考文献数

6

被引用文献数

2

---

This paper presents a finite-element analysis on the free vibration of Japanese drum wood barrels under insufficient material property data. Unlike isotropic material such as steel, wood behaves like an orthotropic composite material, whose elastodynamic characterization in a cylindrical shell needs Young’s modulus in the longitudinal (in-grain) and circumferential (cross-grain) directions, shear modulus, and Poisson ratios. Due to measurement difficulty encountered during the process of testing, only the longitudinal Young’s modulus and the specific gravity of the wood were measured. In the analysis, the finite-element models of the drum were constructed using conical shell elements. The required unknown elastic constants were estimated consecutively by a try-and-error approach, and the estimated values were reached when the computed resonance frequencies matched simultaneously with those of the seven lower modes measured in experiments. In order to accomplish this, both the estimated constants and the finite-element analysis must be within acceptable range of accuracy. It was found that the values of the circumferential (cross-grain) Young’s modulus, which was unknown at the beginning of the study, turns out to be crucial in determining the lower mode resonance frequencies. The usefulness of this analysis is that the estimated elastic constants can now be used for updating the finite-element model. The updated model can then be used calculating the higher order modes which cannot be practically obtained through measurements.

著者

Fumiaki Satoh Takayuki Arai Akira Nishimura

出版者

一般社団法人 日本音響学会

雑誌

Acoustical Science and Technology (ISSN:13463969)

巻号頁・発行日

vol.37, no.4, pp.143-147, 2016-07-01 (Released:2016-07-01)

参考文献数

34

被引用文献数

2

---

In the Acoustical Society of Japan (ASJ), the Research Committee on Education in Acoustics was established in 1997. Although its history is relatively short in comparison with the Administrative Committee on Education in Acoustics in the Acoustical Society of America (ASA), many activities have been steadily carried out. For example, surveys of syllabi (educational plans of subjects in universities) were made. Demonstration tools used in university classes were also surveyed. The extent of our research was not limited to only universities. Textbooks and teaching materials used in elementary schools, junior high schools, and senior high schools were also researched. Furthermore, activities in cooperation with the National Museum of Nature and Science in Japan have been taking place, including an exhibition and a class with acoustic demonstrations and handicrafts for children. We believe that such activities are very important as social contributions of an academic society. In this review, some of our activities, our discussions, and the like will be introduced.

著者

Kei Fujisawa Akira Asada

出版者

一般社団法人 日本音響学会

雑誌

Acoustical Science and Technology (ISSN:13463969)

巻号頁・発行日

vol.36, no.5, pp.438-440, 2015 (Released:2015-09-01)

参考文献数

11

被引用文献数

2

著者

Masayuki Nishiguchi

出版者

一般社団法人 日本音響学会

雑誌

Acoustical Science and Technology (ISSN:13463969)

巻号頁・発行日

vol.27, no.1, pp.43-49, 2006 (Released:2006-01-01)

参考文献数

21

被引用文献数

1 1

---

Harmonic coding is a very powerful technique for the coding of speech at very low bit rates; and the efficient coding of spectral magnitudes sampled at harmonic frequencies is the key to obtaining good coded-speech quality. This paper presents a weighted vector quantization method for spectral vectors composed of a variable number of harmonic magnitudes. It is based on simple, efficient linear dimension conversion and employs a weighted distortion measure that exploits the human auditory sense. A codebook training algorithm using the weighting matrix is also presented. Finally, a low-complexity VQ codebook search technique based on pre-selection is described that reduces the computational complexity to less than 10% of that of an exhaustive search, without perceptible loss of quality. The proposed quantization scheme is used in Harmonic Vector eXcitation Coding (HVXC), which is a very low-bit-rate speech coding algorithm that combines harmonic and stochastic vector representations of LPC residual signals. Due to the high efficiency of this VQ scheme, HVXC provides good communication-quality speech at bit rates as low as 2–4 kbit/s, and was adopted as the ISO/IEC International Standard for MPEG-4 Audio.

著者

Ryosuke O. Tachibana Yasunari Sasaki Hiroshi Riquimaroux

出版者

一般社団法人 日本音響学会

雑誌

Acoustical Science and Technology (ISSN:13463969)

巻号頁・発行日

vol.34, no.4, pp.263-270, 2013-07-01 (Released:2013-07-01)

参考文献数

29

被引用文献数

1 11

---

In this study, we investigated how the temporal envelopes contribute to the recognition of isolated syllables, words, and sentences in noise-vocoded speech, under comparison with the influence of spectral resolution. The spectral and temporal resolutions of speech materials were systematically manipulated by a noise-vocoding technique. Japanese monomoraic syllables, meaningful and meaningless words, and sentences were used as test speech materials. The original speech sound was spectrally separated by a filter bank, and each spectral band was replaced with band noise, preserving its original temporal envelope. Spectral resolution was controlled by varying the number of spectral bands as 4, 8, or 16 bands. Temporal resolution was altered by smoothing the amplitude envelope using a low-pass filter with cut-off frequencies at 4, 8, or 16 Hz. Results demonstrated an increased dependence on temporal resolution in comparison with spectral resolution for the recognition of speech materials at higher structural levels (i.e., monosyllables, words, and sentences). This increased temporal dependence suggests that the temporal envelope in noise-vocoded sentences contained a greater amount of suprasegmental information, such as coarticulations, prosodies, and rhythms, in the original speech sound.

著者

Gerard B. Remijn Emi Hasuo Haruna Fujihira Satoshi Morimoto

出版者

一般社団法人 日本音響学会

雑誌

Acoustical Science and Technology (ISSN:13463969)

巻号頁・発行日

vol.35, no.5, pp.229-242, 2014-05-01 (Released:2014-09-01)

参考文献数

109

被引用文献数

11

---

In 1939, Pauline Davis reported the first study on event-related potentials (ERPs) performed on awake humans. ERPs are time-locked brain potentials that occur in response to cognitive, motor or perceptual events. The events used by Davis were sounds, and in the decades that followed her landmark study ERP research significantly contributed to the knowledge of auditory perception and neurophysiology we have today. ERPs are very well suited to study neural responses to sound stimuli, since the researcher can monitor the brain's registration of sound edges and spectral changes in sound on a millisecond-by-millisecond basis. In this overview we will introduce basic concepts of auditory ERP research. The overview includes descriptions of typical ERP components, experimental paradigms, sound stimuli, research methodology, and ways to analyze data.

著者

Greg Short Keikichi Hirose Nobuaki Minematsu

出版者

一般社団法人 日本音響学会

雑誌

Acoustical Science and Technology (ISSN:13463969)

巻号頁・発行日

vol.35, no.2, pp.73-85, 2014-02-01 (Released:2014-03-01)

参考文献数

34

---

For Japanese speech processing, being able to automatically recognize between geminate and singleton consonants can have many benefits. In standard recognition methods, hidden Markov Models (HMMs) are used. However, HMMs are not good at differentiating between items that are distinguished primarily by temporal differences rather than spectral differences. Also, gemination depends on the length of the sounds surrounding the consonant. Because of this, we propose the construction of a method that automatically distinguishes geminates from singletons and takes these factors into account. In order to do this, it is necessary to determine which surrounding sounds are cues and what the mechanism of human recognition is. For this, we conduct perceptual experiments to examine the relationship between surrounding sounds and primary cues. Then, using these results, we design a method that can automatically recognize gemination. We test this method on two datasets including a speaking rate database. The results attained well-outperform the HMM-based method and overall outperform the case when only the primary cue is used for recognition as well as show more robustness against speaking rate.

著者

Yasuhito Kawai Masahiro Toyoda

出版者

一般社団法人 日本音響学会

雑誌

Acoustical Science and Technology (ISSN:13463969)

巻号頁・発行日

vol.35, no.1, pp.28-34, 2014-01-01 (Released:2014-01-01)

参考文献数

13

被引用文献数

2 4

---

Noise barriers are often very tall alongside highways with heavy traffic. Although these high barriers ensure the desired amount of noise attenuation, they are expensive to install and have a negative effect on the landscape. Consequently, many types of edge-modified noise barriers have been proposed to reduce the necessary height. Herein an alternative noise barrier based on the ``edge-effect'' suppression technique is proposed, and the sound insulation performance is investigated both theoretically and experimentally. Numerical examples indicate that the diffracted sound is greatly attenuated by suppressing the particle velocity in the region with a large velocity amplitude using a thin absorbing material such as cloth with a gradational distribution in impedance. The experimental and theoretical results of insertion loss are in good agreement, validating the theoretical consideration and effectiveness of the cloth installed at the top of the barrier.

著者

Toshima Iwaki Uematsu Hisashi Hirahara Tatsuya

出版者

一般社団法人 日本音響学会

雑誌

Acoustical Science and Technology (ISSN:13463969)

巻号頁・発行日

vol.24, no.5, pp.327-329, 2003 (Released:2003-09-01)

参考文献数

6

被引用文献数

10 24

著者

Takuya Oshima Yasuhiro Hiraguri Masashi Imano

出版者

一般社団法人 日本音響学会

雑誌

Acoustical Science and Technology (ISSN:13463969)

巻号頁・発行日

vol.35, no.2, pp.108-118, 2014-02-01 (Released:2014-03-01)

参考文献数

27

被引用文献数

1 3

---

With the recent progresses in computer performance and simulation techniques, it is becoming feasible to apply full three-dimensional wave-based numerical simulation techniques to large-scale problems of real-life sound propagation outdoors. In the present paper, a reconstruction technique for real-life urban geometries with full reproduction of the roof shapes and for the ground profiles using digital geographic information is presented. Also, a generation technique for the uniform rectilinear grid used in finite-difference time-domain simulations is presented. The types of geographic dataset used for the reconstruction are a digital surface model and a two-dimensional building outline map. For comparison, another geometry with flat building roofs, which is the type of geometry used in former noise-mapping studies using empirical models, is created. Comparison of the results of finite-difference time-domain acoustic simulations performed over the geometries shows sound pressure level differences above and behind buildings. The maximum level difference of 10 dB in magnitude indicates the necessity of proper reconstruction of the roof shapes in real-life urban acoustic simulations.

著者

Naofumi Aoki Yota Morimoto

出版者

一般社団法人 日本音響学会

雑誌

Acoustical Science and Technology (ISSN:13463969)

巻号頁・発行日

vol.34, no.5, pp.342-343, 2013-09-01 (Released:2013-09-01)

参考文献数

5

被引用文献数

2

著者

Masayuki Takada Yoko Fukuda Shin-ichiro Iwamiya

出版者

一般社団法人 日本音響学会

雑誌

Acoustical Science and Technology (ISSN:13463969)

巻号頁・発行日

vol.34, no.3, pp.187-196, 2013-03-01 (Released:2013-05-01)

参考文献数

20

被引用文献数

1 4

---

The Japanese Road Traffic Law states that a vehicle horn should be used only in an emergency or in dangerous locations where a horn sign has been installed. However, drivers frequently use their vehicle horn as a signal when passing each other. Furthermore, pedestrians and cyclists are also honked at by drivers. There may be a negative effect of vehicle horn use on people outside the vehicle. Therefore, a questionnaire survey was carried out to ascertain the current circumstances of vehicle horn use. Respondents were asked about the latest or last-remembered instance of horn use in various situations, both when they were driving and when they were pedestrians. With regard to experiences of being honked at by another driver, the questionnaire included questions concerning place, traffic volume, the aim of horn use, the timing pattern of horn use, and the respondent's psychological reaction when honked at by another driver. It was found that drivers briefly honked their horn to express gratitude, or to gain another's attention, in various places. Long honks such as one long honk or two long honks mostly evoked negative psychological reactions in drivers, such as a feeling that the sound of the horn was startling, noisy, or irritating. Furthermore, pedestrians frequently had negative psychological reactions to horns used to gain their attention or to alert them to danger. More than 40% of nondrivers were displeased with the volume and sound quality of horns.

著者

Ryoichi Takashima Tetsuya Takiguchi Yasuo Ariki

出版者

ACOUSTICAL SOCIETY OF JAPAN

雑誌

Acoustical Science and Technology (ISSN:13463969)

巻号頁・発行日

vol.34, no.3, pp.176-186, 2013-03-01 (Released:2013-05-01)

参考文献数

21

---

This paper presents a talker localization method using only a single microphone, where phoneme hidden Markov models (HMMs) of clean speech are introduced to estimate the acoustic transfer function from the user's position. In our previous work, we proposed a Gaussian mixture model (GMM) separation for estimation of the user's position, where the observed speech is separated into the acoustic transfer function and the clean speech GMM. In this paper, we propose an improved method using phoneme HMMs for separation of the acoustic transfer function. This method expresses the speech signal as a network of phoneme HMMs, while our previous method expresses it as a GMM without considering the temporal phonetic changes of the speech signal. The support vector machine (SVM) for classifying the user's position is trained using the separated frame sequences of the acoustic transfer function. Then, for each test data set, the acoustic transfer function is separated, and the position is estimated by discriminating the acoustic transfer function. The effectiveness of this method has been confirmed by talker localization experiments performed in a room environment.

著者

Ryota Nakasaki Hiroshi Hasegawa Masao Kasuga

出版者

ACOUSTICAL SOCIETY OF JAPAN

雑誌

Acoustical Science and Technology (ISSN:13463969)

巻号頁・発行日

vol.34, no.3, pp.159-165, 2013-03-01 (Released:2013-05-01)

参考文献数

11

被引用文献数

1 5

---

In this paper, we investigated subjective impressions of air-conditioning sounds in a vehicle by using the psychoacoustic parameters of loudness and sharpness. First, we carried out a subjective evaluation using a rating scale method and investigated the relationships between the psychoacoustic parameters and nine evaluation words, quiet, refreshing, heavy, wide, muddy, violent, dry, warm, and cool, that represent impressions of air-conditioning sounds. As a result, we found that the impressions of ``violent'' and ``quiet'' strongly depended on the loudness, and the impressions of ``heavy,'' ``dry,'' ``warm,'' and ``cool'' strongly depended on the sharpness. Next, we performed a factor analysis. As a result, we found that the air-conditioning sounds can be explained by two factors, a volume factor and a thermal factor, which were strongly correlated with the loudness and sharpness, respectively. This result shows that the feelings of heating and cooling perceived from air-conditioning sounds are related to the sharpness. Therefore, a synergetic effect on the heating and cooling performance can be expected by improving the sharpness of air-conditioning sounds.

著者

Ryo Yoneda Masashi Yamada

出版者

ACOUSTICAL SOCIETY OF JAPAN

雑誌

Acoustical Science and Technology (ISSN:13463969)

巻号頁・発行日

vol.34, no.3, pp.166-175, 2013-03-01 (Released:2013-05-01)

参考文献数

11

被引用文献数

1

---

Musical psychologists illustrated musical emotion with various numbers of dimensions ranging from two to eight. Most of them concentrated on classical music. Only a few researchers studied emotion in popular music, but the number of pieces they used was very small. In the present study, perceptual experiments were conducted using large sets of popular pieces. In Experiment 1, ten listeners rated musical emotion for 50 J-POP pieces using 17 SD scales. The results of factor analysis showed that the emotional space was constructed by three factors, ``evaluation,'' ``potency'' and ``activity.'' In Experiment 2, three musicians and eight non-musicians rated musical emotion for 169 popular pieces. The set of pieces included not only J-POP tunes but also Enka and western popular tunes. The listeners also rated the suitability for several listening situations. The results of factor analysis showed that the emotional space for the 169 pieces was spanned by the three factors, ``evaluation,'' ``potency'' and ``activity,'' again. The results of multiple-regression analyses suggested that the listeners like to listen to a ``beautiful'' tune with their lovers and a ``powerful'' and ``active'' tune in a situation where people were around them.

著者

Donna Erickson

出版者

ACOUSTICAL SOCIETY OF JAPAN

雑誌

Acoustical Science and Technology (ISSN:13463969)

巻号頁・発行日

vol.34, no.3, pp.153-158, 2013-03-01 (Released:2013-05-01)

参考文献数

52

被引用文献数

2

著者

Madoka Takimoto Takanori Nishino Katunobu Itou Kazuya Takeda

出版者

一般社団法人 日本音響学会

雑誌

Acoustical Science and Technology (ISSN:13463969)

巻号頁・発行日

vol.28, no.5, pp.335-342, 2007 (Released:2007-09-01)

参考文献数

13

被引用文献数

1 5

---

In this paper, we examine how covering one or both external ears affects sound localization on the horizontal plane. In our experiments, we covered subjects’ pinnae and external auditory canals with headphones, earphones, and earplugs, and conducted sound localization tests. Stimuli were presented from 12 different directions, and 12 subjects participated in the sound localization tests. The results indicate that covering one or both ears decreased their sound localization performance. Front-back confusion rates increased, particularly when covering both outer ears with open-air headphones or covering one ear with an intraconcha-type earphone or an earplug. Furthermore, incorrect answer rates were high when the sound source and the occluded ear that had an intraconcha-type earphone or an earplug were on the same side. We consider that the factors that cause poor performance can be clarified by comparing these results with characteristics of head-related transfer function.

著者

Masanori Morise

出版者

一般社団法人 日本音響学会

雑誌

Acoustical Science and Technology (ISSN:13463969)

巻号頁・発行日

vol.33, no.2, pp.123-125, 2012-03-01 (Released:2012-03-01)

参考文献数

13

被引用文献数

2 10

著者

Ryoko Mugitani Sadao Hiroya

出版者

一般社団法人 日本音響学会

雑誌

Acoustical Science and Technology (ISSN:13463969)

巻号頁・発行日

vol.33, no.4, pp.215-220, 2012-04-01 (Released:2012-07-01)

参考文献数

37

被引用文献数

12

著者

Kanako Ueno Hideki Tachibana

出版者

一般社団法人 日本音響学会

雑誌

Acoustical Science and Technology (ISSN:13463969)

巻号頁・発行日

vol.26, no.2, pp.156-161, 2005 (Released:2005-03-01)

参考文献数

7

被引用文献数

3 5 18

---

In order to investigate the effect of a hall response on music players, we have made various experimental studies up to now. In order to develop this research, one of the most important subjects is to understand the musicians’ perception of the acoustic effects of halls. Musicians generally perceive the acoustic properties of a concert hall by keeping their performing action and by adjusting their playing technique subconsciously. This kind of interactive relationship between musicians and acoustic environment is really important when considering the acoustic values of concert halls for musicians. In this study, musicians’ awareness of concert halls was investigated through interview survey and the cognitive psychological phenomena of musicians were interpreted by applying the “tacit knowing” theory. Then the process to extract the musicians’ perception in experimental studies on concert hall acoustics is discussed.