著者

Junya Koguchi Masanori Morise Hideki Kawahara

出版者

ACOUSTICAL SOCIETY OF JAPAN

雑誌

Acoustical Science and Technology (ISSN:13463969)

巻号頁・発行日

vol.44, no.3, pp.189-192, 2023-05-01 (Released:2023-05-01)

参考文献数

20

著者

Kimihiro Sakagami Fumiaki Satoh Akira Omoto

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.209-211, 2013-03-01 (Released:2013-05-01)

参考文献数

4

被引用文献数

1 5

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

6

---

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

被引用文献数

1

---

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

ACOUSTICAL SOCIETY OF JAPAN

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 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

M. Charles Liberman

出版者

ACOUSTICAL SOCIETY OF JAPAN

雑誌

Acoustical Science and Technology (ISSN:13463969)

巻号頁・発行日

vol.41, no.1, pp.59-62, 2020-01-01 (Released:2020-01-06)

参考文献数

42

被引用文献数

4 8

---

In acquired sensorineural hearing loss, the hearing impairment arises mainly from damage to cochlear hair cells or the sensory fibers of the auditory nerve that innervate them. Hair cell loss or damage is well captured by the changes in the threshold audiogram, but the degree of neural damage is not. We have recently shown, in animal models of noise-damage and aging, and in autopsy specimens from aging humans, that the synapses connecting inner hair cells and auditory nerve fibers are the first to degenerate. This primary neural degeneration, or cochlear synaptopathy, leaves many surviving inner hair cells permanently disconnected from their sensory innervation, and many spiral ganglion cells surviving with only their central projections to the brainstem intact. This pathology represents a kind of ``hidden hearing loss.'' This review summarizes current speculations as to the functional consequences of this primary neural degeneration and the prospects for a therapeutic rescue based on local delivery of neuroptrophins to elicit neurite extension and synaptogenesis in the adult ear.

著者

Dirk Metz

出版者

ACOUSTICAL SOCIETY OF JAPAN

雑誌

Acoustical Science and Technology (ISSN:13463969)

巻号頁・発行日

vol.43, no.2, pp.125-128, 2022-03-01 (Released:2022-03-01)

参考文献数

16

被引用文献数

5

著者

Takayuki Arai Natasha Warner Steven Greenberg

出版者

ACOUSTICAL SOCIETY OF JAPAN

雑誌

Acoustical Science and Technology (ISSN:13463969)

巻号頁・発行日

vol.28, no.1, pp.46-48, 2007 (Released:2007-01-01)

参考文献数

10

被引用文献数

5 7

著者

Shoichi Koyama

出版者

ACOUSTICAL SOCIETY OF JAPAN

雑誌

Acoustical Science and Technology (ISSN:13463969)

巻号頁・発行日

vol.41, no.1, pp.269-275, 2020-01-01 (Released:2020-01-06)

参考文献数

33

被引用文献数

5

---

Estimating and interpolating a sound field from measurements using multiple microphones are fundamental tasks in sound field analysis for sound field reconstruction. The sound field reconstruction inside a source-free region is achieved by decomposing the sound field into plane-wave or harmonic functions. When the target region includes sources, it is necessary to impose some assumptions on the sources. Recently, it has been increasingly popular to apply sparse representation algorithms to various sound field analysis methods. In this paper, we present an overview of sparsity-based sound field reconstruction methods and also demonstrate their application to sound field recording and reproduction.

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

被引用文献数

2

---

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

Ryo Kudo Peter Bornmann Tobias Hemsel Takeshi Morita

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.262-264, 2015-03-01 (Released:2015-05-01)

参考文献数

16

被引用文献数

1

著者

Toshiro Shigetomi Mikio Mori

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.2, pp.83-86, 2016 (Released:2016-03-01)

参考文献数

7

被引用文献数

2

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

11

---

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.

著者

Kazuma Shimizu Kota Fukasawa Takenobu Tsuchiya Nobuyuki Endoh

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.2, pp.178-181, 2015-02-01 (Released:2015-03-01)

参考文献数

17

被引用文献数

1 1

著者

Kyawt Yin Win Tomio Takara

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.32, no.5, pp.174-181, 2011-09-01 (Released:2011-09-01)

参考文献数

12

被引用文献数

5

---

We have introduced a novel Myanmar text to speech (MyanmarTTS) system with rule-based tone synthesis. Myanmar is a tonal language that possesses unique characteristics compared with other tonal languages such as Chinese, Vietnamese and Thai. Such languages have complicated fundamental-frequency (F0) patterns of tones, and F0 is of foremost importance. Myanmar tones are unique in their simplistic pattern related not only to F0 but also, more specifically to duration. Myanmar tones have different durations between short-tone and long-tone groups. In accordance, we defined a tone rule employing two parameters F0 at the center of the syllable and the syllable’s duration. The rule is implemented with a linear F0 pattern. Large variability exists in the F0 and duration uttered by different speakers of different syllables. Hence, for tone synthesis, normalization of the F0 and duration is important and necessary to discriminate tones. We proposed a normalization method and the effectiveness of this method was confirmed in the distribution of the F0 and duration. The intelligibility of the synthesized tone was confirmed through listening tests with correct rates of 95.6% for male and 97.8% for female speech. As a result, we showed that the linear pattern is sufficient for Myanmar tone synthesis.

著者

Kaoru Ashihara Kenji Kurakata Tazu Mizunami Kazuma Matsushita

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.12-19, 2006 (Released:2006-01-01)

参考文献数

25

被引用文献数

10 27

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Hearing thresholds for pure tones from 2 kHz to 28 kHz were measured. A 2AFC procedure combined with a 3-down 1-up transformed up-down method was employed to obtain threshold values that were less affected by listener’s criterion of judgment. From some listeners, threshold values of 88 dB SPL or higher were obtained for a tone at 24 kHz, whereas thresholds could not be obtained from all participants at 26 kHz and above. Furthermore, thresholds were also measured under masking by a noise low-pass filtered at 20 kHz. At frequencies above 20 kHz, the difference of threshold values between with and without the masking noise was a few decibels, indicating that the tone detection was not affected by subharmonic components that might have appeared in the lower frequency regions. The results of measurement also showed that the threshold increased rather gradually for tones from 20 to 24 kHz whereas it increased sharply from 14 to 20 kHz.

著者

Tatsuya Kitamura

出版者

ACOUSTICAL SOCIETY OF JAPAN

雑誌

Acoustical Science and Technology (ISSN:13463969)

巻号頁・発行日

vol.33, no.2, pp.126-128, 2012-03-01 (Released:2012-03-01)

参考文献数

7

被引用文献数

8 7

著者

Tatsuhiro Tanaka Makoto Otani

出版者

ACOUSTICAL SOCIETY OF JAPAN

雑誌

Acoustical Science and Technology (ISSN:13463969)

巻号頁・発行日

vol.44, no.4, pp.317-327, 2023-07-01 (Released:2023-07-01)

参考文献数

29

---

Isotropy is a fundamental property of a diffuse sound field. Although several studies have proposed an isotropy indicator to quantify the extent of the isotropy of a sound field, what is not yet very clear is how to interpret the quantified isotropy using these indicators. This study aims to contribute to the understanding of the isotropy by (i) modifying an existing isotropy indicator based on the spherical harmonic expansion and (ii) presenting isotropic sound field model composed of a finite number of plane waves. Theoretical and numerical investigations show that a limited-degree isotropy can be established by using the isotropy indicator and the isotropic sound field model.

著者

A. J. Patitsas

出版者

ACOUSTICAL SOCIETY OF JAPAN

雑誌

Acoustical Science and Technology (ISSN:13463969)

巻号頁・発行日

vol.43, no.6, pp.297-305, 2022-11-01 (Released:2022-11-01)

参考文献数

27

---

It is verified that the source of the acoustic emissions when beach sand or other squeaky grains are stepped on or impacted by a pestle lies in a thin shear band directly under the pestle. The grain layers in this band slide one over another at a slow creepy pace giving rise to energy transfer, via the stick-slip effect, from the impacting pestle to the elastic vibrations in the shear bands at the grain contact areas. In turn, this vibration energy feeds the elastic modes of vibration along the vertical grain columns or equivalently, the elastic modes of vibration in the shear band under the pestle comprising the vibrating columns, with dominant frequency in the range of 1,000 Hz. In search of an explanation of the acoustic emissions when booming dune sand is pushed by a blade or is freely avalanching, we adopt the concept of the collision shear band, where, due to the high degree of fluidity of the sand mass, the grain layers slide one over another at a brisk pace so that the average collision frequency between grains in two adjacent grain layers defines the dominant frequency of the acoustic emission in the range of 100 Hz.