JASA express letters最新文献

This work extends Doak's momentum potential theory to multi-chemical-component and reactive, time-stationary fluctuating flows. Additional mixture-related components are found to be superimposed on the canonical vortical, acoustic, and thermal parts of momentum fluctuations and total fluctuating enthalpy. These extended relations are used to develop a time-averaged model that relates the acoustic power radiated to the far-field with clearly defined vortical, acoustic, thermal, and compositional near-field sources. The resulting model is designed to offer a more general and comprehensive way to describe the noise generated within combustion chambers.

Human voice directivity shows horizontal asymmetries caused by the shape of the lips or the position of the tooth and tongue during vocalization. This study presents and analyzes the asymmetries of voice directivity datasets of 23 different phonemes. The asymmetries were determined from datasets obtained in previous measurements with 13 subjects in a surrounding spherical microphone array. The results show that asymmetries are inherent to human voice production and that they differ between the phoneme groups with the strongest effect on the [s], the [l], and the nasals [m], [n], and [ŋ]. The least asymmetries were found for the plosives.

Partial credit scoring for speech recognition tasks can improve measurement precision. However, assessing the magnitude of this improvement with partial credit scoring is challenging because meaningful speech contains contextual cues, which create correlations between the probabilities of correctly identifying each token in a stimulus. Here, beta-binomial distributions were used to estimate recognition accuracy and intraclass correlation for phonemes in words and words in sentences in listeners with cochlear implants (N = 20). Estimates demonstrated substantial intraclass correlation in recognition accuracy within stimuli. These correlations were invariant across individuals. Intraclass correlations should be addressed in power analysis of partial credit scoring.

Confidence intervals of location (CIL) of calling marine mammals, derived from time-differences-of-arrival (TDOA) between receivers, depend on errors of TDOAs, receiver location, clocks, and sound speeds. Simulations demonstrate a time-differences-of-arrival-beamforming-locator (TDOA-BL) yields CIL in error by O(10-100) km for experimental scenarios because it is not designed to account for relevant errors. The errors are large and sometimes exceed the distances of detection. Another locator designed for all errors, sequential bound estimation, yields CIL always containing the true location. TDOA-BL have and are being used to understand potential effects of environmental stress on marine mammals; a use worth reconsidering.

A study conducted in Japan aimed to understand how childcare facilities should coexist with the local community. The researchers used a sound survey, demographic survey, and logistic regression analysis to study residents' noise awareness in various areas. They found that higher land prices led to lower approval of new childcare facilities. The study also revealed that those more sensitive to noise and less willing to participate in public events at childcare facilities were more significantly opposed to the establishment of new facilities.

The current study explores whether Mandarin initial and medial voiceless unaspirated and voiceless aspirated stops differ in their tongue positions and post-vocalic voicing during closure. Ultrasound tongue imaging and acoustic data from five Mandarin speakers revealed (1) no consistent pattern for tongue positions among speakers, and (2) no difference in degree of voicing during closure between the two stop series. These findings suggest that tongue position is not a reliable articulatory correlate for Mandarin laryngeal contrasts. This further suggests that aspiration is not correlated with tongue position differences, unlike the reported correlation between voicing and tongue root advancement.

Measuring how well human listeners recognize speech under varying environmental conditions (speech intelligibility) is a challenge for theoretical, technological, and clinical approaches to speech communication. The current gold standard-human transcription-is time- and resource-intensive. Recent advances in automatic speech recognition (ASR) systems raise the possibility of automating intelligibility measurement. This study tested 4 state-of-the-art ASR systems with second language speech-in-noise and found that one, whisper, performed at or above human listener accuracy. However, the content of whisper's responses diverged substantially from human responses, especially at lower signal-to-noise ratios, suggesting both opportunities and limitations for ASR--based speech intelligibility modeling.

Distinguishing shouted from non-shouted speech is crucial in communication. We examined how shouting affects temporal properties of the amplitude envelope (ENV) in a total of 720 sentences read by 18 Swiss German speakers in normal and shouted modes; shouting was characterised by maintaining sound pressure levels of ≥80 dB sound pressure level (dB-SPL) (C-weighted) at a 1-meter distance from the mouth. Generalized additive models revealed significant temporal alterations of ENV in shouted speech, marked by steeper ascent, delayed peak, and extended high levels. These findings offer potential cues for identifying shouting, particularly useful when fine-structure and dynamic range cues are absent, for example, in cochlear implant users.

Reaction times for correct vowel identification were measured to determine the effects of intertrial intervals, vowel, and cue type. Thirteen adults with normal hearing, aged 20-38 years old, participated. Stimuli included three naturally produced syllables (/ba/ /bi/ /bu/) presented whole or segmented to isolate the formant transition or static formant center. Participants identified the vowel presented via loudspeaker by mouse click. Results showed a significant effect of intertrial intervals, no significant effect of cue type, and a significant vowel effect-suggesting that feedback occurs, vowel identification may depend on cue duration, and vowel bias may stem from focal structure.