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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 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.

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.

In this study, passive acoustic monitoring was used to assess the impact of investigator disturbance on the acoustic behavior of a colony of common terns. A graded antipredator response in the colony was hypothesized, which would result in an increase in acoustic energy with increased proximity to investigator disturbance. Human disturbance was found to result in a significant increase in acoustic energy within 20 meters of recorders, though not from farther distances. Our findings provide a framework for assessing the behavioral impact of disturbance on colonies and support the existence of a graded alarm call system in common terns.

A fast numerical time-domain solution for a one-dimensional cochlear transmission-line model was proposed for real-time applications. In this approach, the three-dimensional solver developed by Murakami [J. Acoust. Soc. Am. 150(4), 2589-2599 (2021)] was modified to develop a solution for the one-dimensional model. This development allows the solution to accurately and quickly calculate cochlear responses. The present solution can solve the model in real-time under coarse grid conditions. However, under fine-grid conditions, the computation time is significantly longer than the duration of the signal. Nevertheless, calculations can be performed under the fine grid condition, which previously required much computation time. This fact is essential to applications.

In this paper, an active ultrasound-based touchscreen technology is presented for real-time monitoring of multiple contacts on a glass panel of 20 × 19 cm. Both fundamental Lamb wave modes are generated by sending a linear chirp between 50 and 100 kHz to a single piezoelectric ceramic lead zirconate titanate. Measurement is performed using four piezoelectric ceramic lead zirconate titanate elements, and real-time localization and detection are performed on a system on module i.MX 8 M Nano. Results show that Lamb waves can be used for real-time multi-touch detection and localization on both sides of the panel. Moreover, the prototype developed allows for relative pressure measurement.