JASA express letters最新文献

Greek uses H*, L + H*, and H* + L, all followed by L-L% edge tones, as nuclear pitch accents in statements. A previous analysis demonstrated that these accents are distinguished by F0 scaling and contour shape. This study expands the earlier investigation by exploring additional cues, namely, voice quality, amplitude, and duration, in distinguishing the pitch accents, and investigating individual variability in the selection of both F0 and non-F0 cues. Bayesian multivariate analysis and hierarchical clustering demonstrate that the accents are distinguished not only by F0 but also by additional cues at the group level, with individual variability in cue selection.

Input/output (I/O) functions of distortion-product otoacoustic emissions (DPOAEs) may contain sudden amplitude minima (notches) although they are measured in animals with a negligible reflection source. We measured DPOAEs in humans and analyzed the data by time-frequency filtering to decompose the nonlinear-distortion and coherent-reflection components of DPOAE. The presented I/O functions of the nonlinear-distortion component contain notches. We suggest that because these notches are present only in the nonlinear-distortion component, they result from destructive interference between distortion-product wavelets coming from the primary generation region. Simulations conducted with a nonlinear cochlear model showed qualitative similarities with the presented experimental results.

This study examined the influence of stimulus properties on sound externalization when listening with hearing aids. Normally hearing listeners were presented with broadband "tokens" (environmental sounds and speech) from loudspeakers, and rated externalization using a continuous scale. In separate blocks, they listened unaided or while wearing behind-the-ear hearing aids with closed domes and low gain (linear or compressive). There was a significant influence of token on ratings, even for unaided listening, and the effect of hearing aids depended on token. An acoustic analysis indicated that hearing aids were more likely to disrupt externalization for peakier sounds with a low-frequency emphasis.

The small size, high sensitivity, and immunity to electromagnetic interference of fibre-optic ultrasound sensors make them highly attractive for applications in biomedical imaging and metrology. Typically, such sensors rely on optically resonant structures, such as Fabry-Perot cavities, that require elaborate fabrication techniques. Here, an alternative fibre-optic ultrasound sensor is presented that comprises a simple deformable and reflective structure that was deposited using simple dip-coating. Interrogation with a laser Doppler vibrometer demonstrated how this sensor achieved a sensitivity, signal-to-noise ratio, and noise-equivalent pressure that outperformed piezoelectric hydrophones, whilst offering a highly miniature form factor, turn-key operation, and simple fabrication.

Acoustic measurements using sine sweeps are prone to background noise and non-stationary disturbances. Repeated measurements can be averaged to improve the resulting signal-to-noise ratio. However, averaging leads to poor rejection of non-stationary high-energy disturbances and, in the case of a time-variant environment, causes attenuation at high frequencies. This paper proposes a robust method to combine repeated sweep measurements using across-measurement median filtering in the time-frequency domain. The method, called Mosaic, successfully rejects non-stationary noise, suppresses background noise, and is more robust toward time variation than averaging. The proposed method allows high-quality measurement of impulse responses in a noisy environment.

The mouth of a speaker is generally close to the microphones of speech communication devices, such as headsets and phones, whereas noise sources are more distant from the microphones. Hence, near-field enhancement using microphone arrays is a promising strategy for noise suppression. This study deals with radiation mode-based microphone arrays and mainly focuses on experimentally validating the methodology. Because the radiation mode-based microphone array can be approximated as a gradient microphone, the difference between them and the advantage of the former over the latter are clarified by comparing the beampatterns.

High vowels have higher f0 than low vowels, creating a context effect on the interpretation of f0. Since onset F0 is a cue to stop voicing, the vowel context is expected to influence voicing judgements. Listeners categorized syllables starting with high ("bee"-"pea") and low ("bye"-"pie") vowels varying orthogonally in VOT and onset F0. Listeners made use of both cues as expected. Furthermore, vowel height affected listeners' categorization. Syllables with the low vowel /a/ elicited more voiceless responses compared to syllables with the high vowel /i/. This suggests that listeners compensate for vowel intrinsic effects when making other phonemic judgements.

Building on previous observations of variability in speech research, we examine variability in speech perception study materials associated with the specific talker and contrast under examination. English-speaking listeners completed a web-based auditory AXB task involving Hindi dental-retroflex stop contrasts produced by four talkers. Main effects of talker and contrast, as well as the interaction of the two, were observed. Further, there was a great deal of individual listener variation. These findings complicate our ability to characterize the difficulty that Hindi dental-retroflex contrasts pose for English speakers, and lead to critical questions concerning the generalizability of speech perception study findings.

Freshwater turtles exhibit temporary threshold shifts (TTS) when exposed to broadband sound, but whether frequency-restricted narrowband noise induces TTS was unknown. Underwater TTS was investigated in two freshwater turtle species (Emydidae) following exposures to 16-octave narrowband noise (155-172 dB re 1 μPa2 s). While shifts occurred in all turtles at the noise center frequency (400 Hz), there were more instances of TTS and greater shift magnitudes at 12 octave above the center frequency, despite considerably lower received levels. These frequency-specific data provide new insight into how TTS manifests in turtles and expand empirical models to predict freshwater turtle TTS.

Previous research suggests that noise sensitivity is related to inefficient auditory processing that might increase the mental load of noise and affect noise evaluation. This assumption was tested in an experiment using a dual-task paradigm with a visual primary task and an auditory secondary task. Results showed that participants' noise sensitivity was positively correlated with mental effort. Furthermore, mental effort mediated the effect of noise sensitivity on loudness and unpleasantness ratings. The results thus support the idea that noise sensitivity is related to increased mental effort and difficulties in filtering auditory information and that situational factors should be considered.