著者
Yoshiki Masuyama Tsubasa Kusano Kohei Yatabe Yasuhiro Oikawa
出版者
ACOUSTICAL SOCIETY OF JAPAN
雑誌
Acoustical Science and Technology (ISSN:13463969)
巻号頁・発行日
vol.40, no.3, pp.186-197, 2019-05-01 (Released:2019-05-01)
参考文献数
29

For musical instrument sounds containing partials, which are referred to as modes, the decaying processes of the modes significantly affect the timbre of musical instruments and characterize the sounds. However, their accurate decomposition around the onset is not an easy task, especially when the sounds have sharp onsets and contain the non-modal percussive components such as the attack. This is because the sharp onsets of modes comprise peaky but broad spectra, which makes it difficult to get rid of the attack component. In this paper, an optimization-based method of modal decomposition is proposed to overcome it. The proposed method is formulated as a constrained optimization problem to enforce the perfect reconstruction property which is important for accurate decomposition and causality of modes. Three numerical simulations and application to the real piano sounds confirm the performance of the proposed method.
著者
Yokota Takatoshi Sakamoto Shinichi Tachibana Hideki
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.23, no.1, pp.40-46, 2002 (Released:2002-02-08)
参考文献数
7
被引用文献数
20 33 58

This paper presents visualization of transient sound propagation in 2-dimensional room sound fields in which the typical shapes of concert halls are modeled by applying the finite difference time domain method. As a basic study on room acoustic design, sound propagation in rooms, scattering effect of acoustic diffusers and reflection characteristics of suspended panel arrays are investigated. Through the investigation, it has been confirmed that this kind of visualization technique is very effective to get intuitive comprehension of complex acoustic phenomena which occur in rooms. The technique can be useful tool for discussion on room and acoustic treatment between acoustic engineers and architects.
著者
Kohei Yatabe Yoshiki Masuyama Tsubasa Kusano Yasuhiro Oikawa
出版者
ACOUSTICAL SOCIETY OF JAPAN
雑誌
Acoustical Science and Technology (ISSN:13463969)
巻号頁・発行日
vol.40, no.3, pp.170-177, 2019-05-01 (Released:2019-05-01)
参考文献数
48

As importance of the phase of complex spectrogram has been recognized widely, many techniques have been proposed for handling it. However, several definitions and terminologies for the same concept can be found in the literature, which has confused beginners. In this paper, two major definitions of the short-time Fourier transform and their phase conventions are summarized to alleviate such complication. A phase-aware signal-processing scheme based on phase conversion is also introduced with a set of executable MATLAB functions (https://doi.org/10/c3qb).
著者
Fumiaki Satoh Kimihiro Sakagami Akira Omoto
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.165-172, 2016-07-01 (Released:2016-07-01)
参考文献数
11

In an introductory course for environmental/architectural acoustics in universities, it is often used the teaching method based on soundscape, in which students are asked to make a sound map with listening their surrounding acoustic environment. However, if objective measurement of sound pressure level or frequency spectrum can be introduced in such a course, it will interest students in environmental acoustics, and enable them to discuss the acoustic environment more profoundly. Measurement apparatuses are usually expensive and difficult to be used in such a course. Therefore, we consider to use a smartphone: using a smartphone with acoustic measurement applications, it can be possible to introduce an objective measurement in such an introductory course for beginners. In this study, first some applications for acoustic measurement are examined to confirm their accuracy as well as the effect of a simple handmade windscreen. Secondly, using suitable applications, as a possible work in the course, sound maps with measurement results by a smartphone are made and their examples are shown. Finally, some issues to introduce this method in actual courses are discussed.
著者
Kei Sawada Kei Hashimoto Keiichiro Oura Yoshihiko Nankaku Keiichi Tokuda
出版者
ACOUSTICAL SOCIETY OF JAPAN
雑誌
Acoustical Science and Technology (ISSN:13463969)
巻号頁・発行日
vol.39, no.2, pp.119-129, 2018-03-01 (Released:2018-03-01)
参考文献数
35

This paper proposes a method for constructing text-to-speech (TTS) systems for languages with unknown pronunciations. One goal of speech synthesis research is to establish a framework that can be used to construct TTS systems for any written language. Generally, language-specific knowledge is required to construct TTS systems for a new language. However, it is difficult to acquire language-specific knowledge in each new language. Therefore, constructing a TTS system for a new language entails huge costs. To address this problem, we investigate a framework for automatically constructing a TTS system from a target language database consisting of only speech data and corresponding Unicode texts. In the proposed method, pseudo phonetic information of the target language with unknown pronunciation is obtained by a speech recognizer of a rich-resource proxy language. Then, a grapheme-to-phoneme converter and a statistical parametric speech synthesizer are constructed based on the obtained pseudo phonetic information. The proposed method was applied to Japanese and was evaluated in terms of objective and subjective measures. Additionally, we challenged the construction of TTS systems for nine Indian languages using the proposed method, and TTS systems were evaluated in the Blizzard Challenge 2014 and 2015.
著者
Daichi Kitamura
出版者
ACOUSTICAL SOCIETY OF JAPAN
雑誌
Acoustical Science and Technology (ISSN:13463969)
巻号頁・発行日
vol.40, no.3, pp.155-161, 2019-05-01 (Released:2019-05-01)
参考文献数
35
被引用文献数
1

Nonnegative matrix factorization (NMF) is a powerful technique of extracting meaningful patterns from an observed matrix and has been used for many applications in the audio signal processing field. In this article, the principle of NMF and some extensions based on a complex generative model are reviewed. Also, their application to audio source separation is presented.
著者
Tetsunori Kobayashi Shinya Fujie
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.2, pp.64-72, 2013-02-01 (Released:2013-03-01)
参考文献数
22
被引用文献数
3 4

Functions have been implemented in various robots to enable them to follow a conversation protocol. The paralinguistic information involved in prosody and posture expression is used to improve the transparency of the conversational states, especially the protocol, thereby effectively contributing to natural and efficient communication. Information is communicated incrementally to enable error handling. Various rules for selecting conversation participants, forming a communication group, and turn-taking are followed. Since all the actions of a conversational robot are explicitly controlled, such robots should be useful for revealing important heretofore unknown conversational functions.
著者
Masahiro Harazono Daichi Kitamura Masashi Nakayama
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.5, pp.301-309, 2012-05-01 (Released:2012-09-01)
参考文献数
7

As a factor to characterize the sound of an electric guitar, it is thought that a characteristic of the pickup contributes most. The pickups most often used are classified roughly into single-coil models and humbucking models. The single-coil pickup is made by winding the thin wires with several thousand turns of coils around six polarizing pole pieces each corresponding to a string of the guitar, and the change in the magnetic reluctance owing to the string vibration that causes the change in the magnetic flux is transformed into an electrical signal. The humbucking pickup is composed of one magnetic circuit with two single-coil pickups, and made to be in phase electrically and out of phase magnetically for the purpose of removing circumference magnetic noise. In this paper, the response of the humbucking pickup excited by a string vibration set up by a real commercial solid body electric guitar is analyzed, and a simulation result is shown to agree with an actual measured value with sufficient precision. In addition, the response of the humbucking pickup imitated with two single-coil pickups is compared with the single-coil pickup and some additional considerations in the characteristics have been gained through analysis.
著者
Kenji Ishikawa Yasuhiro Oikawa Yoshio Yamasaki
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.408-418, 2015 (Released:2015-09-01)
参考文献数
23
被引用文献数
1

Light propagating through a sound field is affected by variations in the density of the medium caused by sound. Therefore, acoustical measurements using light have been studied. The popular measurement methods use the phase shift of the transmitted light. Because they detect integrated acoustical quantities along the optical path of the detected light, time and effort are required to measure the quantities at a single point. On the other hand, single-point acoustical particle velocity measurement by light scattering has been proposed. Using light scattering enables the measurement of non-integrated quantities because the scattered light includes only the acoustical information at a scattering point. However, a method of non-invasive sound pressure measurement at a single point in a free field has not been established. This paper proposes sound pressure measurement at a scattering point, in which the light scattered by particles in the sound field is observed. The intensity of light scattered in the sound field indicates the sound pressure because the intensity of the scattered light is proportional to the density of scatterers. The theory of light scattering by sounds is formalized, and sound measurement experiments with light scattering are also conducted using water drops and air particles as scatterers.
著者
Go Ashida
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.4, pp.275-285, 2015-04-01 (Released:2015-07-01)
参考文献数
154
被引用文献数
1

The barn owl is a nocturnal predator with excellent sound localization ability. Due to the asymmetric ears of this bird, the interaural time and level differences, respectively, provide information for the horizontal and vertical direction of a sound source. Forty years of behavioral, anatomical and physiological research on the owl's auditory system have revealed that these two acoustic cues are computed in parallel and hierarchical neural pathways, which converge at the midbrain to form an auditory space map. This neural representation of the acoustic world, calibrated with the visual system, underlies the highly precise sound localization behavior of the barn owl.
著者
Yusuke Torikai Dai Kuze Junko Kurosawa Yasuhiro Oikawa Yoshio Yamasaki
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.6, pp.500-506, 2015 (Released:2015-11-01)
参考文献数
15

We investigated a new communication-aid system focused on bone-conduction through a tooth, for listening to and recording voices. In this paper, we developed a tooth-conduction microphone (TCM) and evaluate the articulation of tooth-conducted voice (TCV). Because the TCM has the shape of one's dental mold, it is wearable like a mouthpiece. Moreover, it can extract tooth vibration during phonation as TCV. To evaluate articulation of TCV, we adopted monosyllable articulation for subjective assessment and linear predictive coding cepstral distance for objective assessment. The results of articulation show that TCV is not sufficiently clear compared to air-conducted. However, it is confirmed that TCV is robust to environmental noise because the accuracy rate is not decreased when the TCV is recorded under high ambient noise.
著者
Akira Nishimura Nobuo Koizumi
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.31, no.2, pp.172-180, 2010-03-01 (Released:2010-03-01)
参考文献数
15
被引用文献数
1

A method of sampling jitter measurement based on time-domain analytic signals is proposed. Computer simulations and actual measurements were performed to compare the proposed method with the conventional method, in which jitter is evaluated from the amplitudes of sideband spectra for observed signals in the frequency domain. The results show that the proposed method is effective in that it 1) provides high temporal resolution as a result of the direct derivation of the jitter waveform, 2) achieves higher accuracy in the measurement of jitter amplitude, and 3) can separate phase modulation that originate in sampling jitter from amplitude modulation that originate in digital-to-analog and analog-to-digital conversion processes. Suitable measurement conditions and measurements to separate the effects of jitter in a digital-to-analog converter and an analog-to-digital converter are described.
著者
Katsuhiko Yamamoto Toshio Irino Toshie Matsui Shoko Araki Keisuke Kinoshita Tomohiro Nakatani
出版者
ACOUSTICAL SOCIETY OF JAPAN
雑誌
Acoustical Science and Technology (ISSN:13463969)
巻号頁・発行日
vol.40, no.2, pp.84-92, 2019-03-01 (Released:2019-03-01)
参考文献数
27

The speech-based envelope power spectrum model (sEPSM) was developed to predict the speech intelligibility of sounds produced by nonlinear speech enhancement algorithms such as spectral subtraction. It is a linear model with a linear, level-independent gammatone (GT) filterbank as the front-end. Therefore, it seems difficult to evaluate speech sounds with low and high sound pressure levels (SPLs) consistently because the intelligibility of the speech is dependent on the SPL as well as the signal-to-noise ratio. In this study, the sEPSM was extended with the dynamic compressive gammachirp (dcGC) auditory filterbank and a ``common'' normalization factor of the modulation power spectrum component to improve the predictability of the model. For evaluating the proposed model, we performed subjective experiments on the intelligibility of speech sounds enhanced by spectral subtraction and a Wiener filter algorithm. We compared the subjective speech intelligibility scores with the objective scores predicted by the proposed dcGC-sEPSM, original GT-sEPSM, and other well-known conventional methods such as the short-time objective intelligibility measure (STOI), coherence speech intelligibility index (CSII), and hearing aid speech perception index (HASPI). The result shows that the proposed dcGC-sEPSM predicted the subjective results better did than the other methods.
著者
Demián García Violini Ricardo S. Sánchez-Peña Ariel Velis Carlos Posse
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.1, pp.21-29, 2016-01-01 (Released:2016-01-01)
参考文献数
31

In this work, three experiments are conducted. In a realistic environment (freeway), a database for the noise dynamics versus velocity in a motorcycle helmet is computed. Next, under the controlled conditions of an anechoic chamber, the models for the feedback (FB) and feedforward (FF) paths in the helmet are obtained by a filtering and identification process. Finally, in the same chamber, a hybrid (FB+FF) robust controller is tested against the actual noise measured in the freeway, and it achieves attenuations between 20 and 30 dB.
著者
Motoaki Sano Yutaka Nakagawa Tsuneyoshi Sugimoto Takashi Shirakawa Kaoru Yamagishi Toshiaki Sugihara Motoyoshi Ohaba Sakae Shibusawa
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.3, pp.248-253, 2015-03-01 (Released:2015-05-01)
参考文献数
26
被引用文献数
2

In order to estimate the water stress of a plant, the natural frequency of the leaf-stalk system was investigated. As a means of vibrating the leaf, acoustic radiation force was utilized, and the successive measurement of the natural frequency of ``komatsuna'', which was cultivated in a pot of soil, was performed for a week until wilting after stopping irrigation. As a result, it was found that the natural frequency is decreased drastically by the wilting of the leaf before the drooping occurs. In addition, daily variation was also observed in the early days, but it was gradually suppressed as the day went on. These behaviors were discussed referring to a simple cantilever beam model. In conclusion, it was ascertained that the acoustic radiation force is efficient for vibrating a leaf-stalk system. Furthermore, it was confirmed that measuring the natural frequency of the leaf-stalk system is effective for the early detection of water stress of a plant.