Search

Typhoon-induced P-wave microseisms can be observed using seismological arrays and analyzed for the seismic monitoring of ocean storms. This paper presents a frequency-domain beamforming (FB) method that integrates a three-dimensional (3-D) Earth model to better capture the heterogeneities in the subsurface structure, and therefore yield more accurate ray-tracing and travel-time predictions. This method is applied to the Super Typhoon Lupit (2009) using seismological array observations from the Northeast China Extended Seismic Array (NECESSArray) and high-sensitivity seismograph network in Japan (Hi-net). The results show that the localized P-wave microseism source regions based on the 3-D model are in better agreement with the theoretical source regions and typhoon centers than those based on a conventional one-dimensional (1-D) model. The significance of using a 3-D model instead of a 1-D model in the FB method is further investigated by comparing the consistency of the localization results for the two different arrays, with the localized source regions being more mutually concordant when using the 3-D model. The results demonstrate that integrating the 3-D model into the FB method improves the accuracy of locating the typhoon-induced P-wave microseism source regions. [ABSTRACT FROM AUTHOR]

In this paper, a sperm whale click analysis scheme is proposed in order to calculate the position of individual sperm whales in a group using data received at two arrays deployed near the surface. The proposed method mainly consists of two parts: short baseline (SBL) with classification and long baseline (LBL) with class matching. In SBL with classification, a click is automatically detected, and its direction of arrival is calculated. The clicks are then classified based on their direction vectors. The class data are then sent together with direction data and matched to the other array’s class data. LBL with class matching is used for localization. The classification algorithm can be used to estimate the number of whales clicking and to list potential candidates for LBL matching. As a result, the proposed method is able to localize the positions of the whales in a group. The performance of the proposed method is evaluated using data recorded off Ogasawara islands with two arrays near the surface. The three-dimensional underwater trajectories of six sperm whales are extracted to demonstrate the capability of the proposed method. [ABSTRACT FROM AUTHOR]

Annoyance to noise is probably a good measure of the potential for complaint and community action. Each individual’s degree of annoyance to noise cannot be accurately predicted from conventional laboratory studies and social surveys. Therefore, a logistic prediction model for individual allowable noise levels has been developed. In a previous paper [K. Furihata et al., Acta Acust. Acust. 93, 73–83 (2007)], an annoyance scale using the most frequently used annoyance ratings related to noise for community noise assessment in Japan was constructed. The dose-response relationships were obtained by actually listening to sounds in a field situation (1474 subjects) carried out at 14 metropolitan cities in Japan. The logistic prediction model was developed using the logistic regression parameters estimated from each cumulative percentage curve of seven annoyance scale scores based on all data (n=2940). To verify the hypothesis, individual relationships between annoyance and LAeq, (5 min) for 24 normal-hearing subjects were constructed using a laboratory experiment. The main conclusion drawn from the results is that if at least one dose-response relation is obtained from each subject, the model can predict whether a sound is annoying or not from its LAeq,(5 min) value. Moreover, validation of the model is needed in a field situation. [ABSTRACT FROM AUTHOR]

This article presents information about the architectural acoustics of the Tokyo Opera City Concert Hall in Japan. The author believes that the inverted-V cross-section ceilings could be an improvement on the shoebox-shaped halls. Reverberation time calculations are much more accurately predicted in the inverted-V design. Several churches that have the inverted-V design and excellent acoustics are mentioned. The article also presents information on the acoustical engineering of the First Presbyterian Church of Stamford, Connecticut and efforts to restore it to its original design.

The article reviews several patents related to acoustics. A patent for a resonance method for measuring thickness was filed in Japan in September 2003. A patent for a speaker for vehicle and mounting structure of the speaker was also filed in Japan in November 2001. A patent was filed in Canada in August 2001 for an electromagnetic piezoelectric acoustic sensor. A patent filed in Great Britain in September 2001 describes loudspeaker systems with a pancake arrangement in which tubes are nested in a spiral configuration.

The room acoustical parameters reverberation time, RT; early decay time, EDT; clarity, C80; time gravity, Tg; bass ratio, BR; strength, G; initial time delay gap, ITDG; interaural cross-correlation coefficient, IACCE, the where binaural quality index BQI equals [1-IACCE3]; and stage support, ST1 were measured in 18 major chamber-music halls in Austria, Germany, the Netherlands, Czech Republic, Switzerland, and Japan, employing procedures in accordance with ISO 3382 (1997). In combination with the architectural data, the intrinsic objective parameters for the acoustics of chamber-music halls and their variation range were examined. The results of these studies reveal four pertinent orthogonal parameters: RT, G, ITDG, BQI. General design guidelines for a chamber-music hall are presented. [ABSTRACT FROM AUTHOR]

The relationship between prosody and perceived affect involves multiple variables. This paper explores the interplay of three: voice quality, f 0 contour, and the hearer's language background. Perception tests were conducted with speakers of Irish English, Russian, Spanish, and Japanese using three types of synthetic stimuli: (1) stimuli varied in voice quality, (2) stimuli of uniform (modal) voice quality incorporating affect-related f 0 contours, and (3) stimuli combining specific non-modal voice qualities with the affect-related f 0 contours of (2). The participants rated the stimuli for the presence/strength of affective colouring on six bipolar scales, e.g., happy-sad . The results suggest that stimuli incorporating non-modal voice qualities, with or without f 0 variation, are generally more effective in affect cueing than stimuli varying only in f 0 . Along with similarities in the affective responses across these languages, many points of divergence were found, both in terms of the range and strength of affective responses overall and in terms of specific stimulus-to-affect associations. The f 0 contour may play a more important role, and tense voice a lesser role in affect signalling in Japanese and Spanish than in Irish English and Russian. The greatest cross-language differences emerged for the affects intimate, formal , stressed , and relaxed.

This paper examines vowel-to-vowel lingual coarticulation in sequences of vowel-bilabial consonant-vowel, where the duration of the oral closure for the consonant is either long or short. Native speakers of Japanese served as subjects. The linguistic material consisted of Japanese word pairs that only differed in the duration of the labial consonant, which was either long or short. Recordings were made of lip and tongue movements using a magnetometer system. It was hypothesized that there would be greater vowel-to-vowel coarticulation in the context of a short consonant, since a long consonant would allow the tongue more time to move. The overall results do not show any strong support for this hypothesis, however. Subjects modulate the speed of the tongue movement between the two vowels, making it slower during the long than during the short consonant.

Two basic types of wood are used to make stringed musical instruments: woods for soundboards (top plates) and those for frame boards (back and side plates). A new way to classify the acoustical properties of woods and clearly separate these two groups is proposed in this paper. The transmission parameter (product of propagation speed and Q value of the longitudinal wave along the wood grain) and the antivibration parameter (wood density divided by the propagation speed along the wood grain) are introduced in the proposed classification scheme. Two regression lines, drawn for traditional woods, show the distinctly different functions required by soundboards and frame boards. These regression lines can serve as a reference to select the best substitute woods when traditional woods are not available. Moreover, some peculiarities of Japanese string instruments, which are made clear by comparing woods used for them with woods used for Western and Chinese instruments, are briefly discussed.

This paper examines tongue movements in stop and fricative consonants where the duration of the oral closure/constriction for the consonant is varied for linguistic purposes. Native speakers of Japanese served as subjects. The linguistic material consisted of Japanese word pairs that only differed in the duration of the lingual consonant, which was either long or short. Recordings were made of tongue movements using a magnetometer system. Results show a robust difference in closure duration between the long and short consonants. Overall, the path of the tongue movement during the consonant was longer for the long than for the short consonant. All speakers decreased the speed of the tongue movement during the long consonant. These adjustments in tongue movements were most likely made to maintain the contact between the tongue and the palate for the closure and constriction.

This paper describes a method for determining the shape of the midsagittal tongue contour from the positions of points on the tongue surface. The positions of the points and the tongue shape were measured simultaneously by using an alternating magnetic field device and an ultrasonic B-mode scanner for continuous speech utterances. A comparison between the magnetic and the ultrasonic data revealed that the average measurement difference between the two types of data was 1.16 mm. The shape of the tongue contour was then represented by multivariable linear regression of the magnetically determined positions. The results of the regression analysis showed that the tongue contour was estimated, from four positions on the tongue, with an average estimation error of 1.24 mm. This estimation error could be reduced to 0.84 mm when there was no measurement error between the magnetic and the ultrasonic data, and it was further reduced to 0.43 mm when the receiver coils of the magnetic device were positioned optimally on the tongue. It was also shown that the number of data frames for calculating the regression coefficients could be reduced, while maintaining the estimation accuracy, by appropriately selecting data frames. Finally, the tongue shape was estimated successfully for several phonemes from the magnetically determined positions, thus demonstrating the usefulness of this method for observing the articulatory configuration of the tongue.

The McGurk effect is a phenomenon that demonstrates a perceptual fusion between auditory and visual (lip-read) information in speech perception under the condition of audio-visual discrepancy, created by dubbed video tapes. This paper investigated whether or not the McGurk effect could be extended to Japanese subjects listening to Japanese syllables of different auditory intelligibility. The audio and video signal of a female talker's speech for ten Japanese syllables (/ba/, /pa/, /ma/, /wa/, /da/, /ta/, /na/, /ra/, /ga/, /ka/) was combined on videotapes, giving 100 audio-visual stimuli. These stimuli were presented to ten Japanese subjects who were required to identify the stimuli as heard speech in both noise-added and noise-free conditions. For both conditions, the intelligibility of the auditory stimuli was measured, by presenting the audio-alone stimuli. The results showed that, in the noise-free condition, the McGurk effect was small and almost limited to auditory stimuli of which the intelligibility was less than 100%. In the noise-added condition, the McGurk effect was very strong and widespread. These results indicate that the "Japanese McGurk effect" is less easily induced than the English one, and that it depends on the auditory intelligibility of the speech signal.

The goal of cross-language voice conversion is to preserve the speech characteristics of one speaker when that speaker's speech is translated and used to synthesize speech in another language. In this paper, two preliminary studies, i.e., a statistical analysis of spectrum differences in different languages and the first attempt at a cross-language voice conversion, are reported. Speech uttered by a bilingual speaker is analyzed to examine spectrum difference between English and Japanese. Experimental results are (1) the codebook size for mixed speech from English and Japanese should be almost twice the codebook size of either English or Japanese; (2) although many code vectors occurred in both English and Japanese, some have a tendency to predominate in one language or the other; (3) code vectors that predominantly occurred in English are contained in the phonemes /r/, /ae/, /f/, /s/, and code vectors that predominantly occurred in Japanese are contained in /i/, /u/, /N/; and (4) judged from listening tests, listeners cannot reliably indicate the distinction between English speech decoded by a Japanese codebook and English speech decoded by an English codebook. A voice conversion algorithm based on codebook mapping was applied to cross-language voice conversion, and its performance was somewhat less effective than for voice conversion in the same language.

This paper examines the relationship between dynamic spectral features and the identification of Japanese syllables modified by initial and/or final truncation. The experiments confirm several main points. "Perceptual critical points," where the percent correct identification of the truncated syllable as a function of the truncation position changes abruptly, are related to maximum spectral transition positions. A speech wave of approximately 10 ms in duration that includes the maximum spectral transition position bears the most important information for consonant and syllable perception. Consonant and vowel identification scores simultaneously change as a function of the truncation position in the short period, including the 10-ms period for final truncation. This suggests that crucial information for both vowel and consonant identification is contained across the same initial part of each syllable. The spectral transition is more crucial than unvoiced and buzz bar periods for consonant (syllable) perception, although the latter features are of some perceptual importance. Also, vowel nuclei are not necessary for either vowel or syllable perception.