JASA express letters最新文献

Traditional research attributes the modulated sidebands of ship radiation line-spectrum signals to reflections off rough ocean surfaces, but the Doppler effect caused by vessel motion may also contribute. This study establishes a micro-Doppler signal model based on wave-induced ship swaying, explaining that this phenomenon arises from the ship oscillatory motion in waves. The sea trial results demonstrate that the peak wave frequency, the frequency of ship micro-motions, and the micro-Doppler characteristic frequency recorded by the beacon exhibit a sudden frequency shift occurring synchronously from 0.075 to 0.115 Hz, thereby verifying the validity of the proposed model.

Dynamical theories of speech use computational models of articulatory control to generate quantitative predictions and advance understanding of speech dynamics. The addition of a nonlinear restoring force to task dynamic models is a significant improvement over linear models, but nonlinearity introduces challenges with parameterization and interpretability. We illustrate these problems through numerical simulations and introduce solutions in the form of scaling laws. We apply the scaling laws to a cubic model and show how they facilitate interpretable simulations of articulatory dynamics and can be theoretically interpreted as imposing physical and cognitive constraints on models of speech movement dynamics.

Anxiety disorders (AD) and major depressive disorders (MDD) are growing in prevalence, yet many people suffering from these disorders remain undiagnosed due to known perceptual, attitudinal, and structural barriers. Methods, tools, and technologies that can overcome these barriers and improve screening rates are needed. Tools based on automated analysis of acoustic voice could help bridge this gap. Comorbid AD/MDD presents additional challenges since some effects of AD and MDD oppose one another. Here, acoustic models that use acoustic and phonemic data from verbal fluency tests to discern the presence of comorbid AD/MDD are presented, with the best results of F1 = 0.83.

Adaptive matched field processing (AMFP) has proven effective for source localization in deep-water environments. However, when the target is in motion, the need for numerous snapshot samples can lead to distortion in covariance estimation, degrading AMFP performance. A synthetic AMFP method has been proposed to compensate for the phase of multi-snapshot signals, enhancing AMFP performance. Additionally, a rough estimation of target velocity is obtained. The efficacy of the method has been validated through numerical simulations and experimental data, with results showing that, within a 9 km range, the average localization error is reduced by 1.45 km compared to traditional AMFP.

The phase of the seabed frequency-domain reflection coefficient potentially contains valuable information on the geoacoustic properties in a layered/refracting seabed. However, heretofore, the phase has not been exploited. Measurements of phase are presented in an area of thick mud at the New England Mud Patch. In addition, a model is presented along with the modeling results. While this is only a first step towards understanding the potential value of exploiting the phase, it seems clear that in some instances, the phase not only contains valuable geoacoustic information, but carries a higher information content than the magnitude.

Observations from a broadband acoustic experiment in deep water probe the temporal behavior of mid-frequency propagation through sound-speed fine structure advected by internal waves. The measured phases of two arrivals with similar propagation paths at 1.8 km range are sampled every 63.5 ms for 30 min. Simultaneous measurements of ocean fine structure near the propagation are used to model the changing arrival phase. The phase difference between arrivals is analyzed to understand changes in the underwater acoustic channel at the meter scale. A comparison between modeled and observed phase difference highlights an internal wave driven signal in the acoustic observations.

An analysis of ambient noise data collected from seven locations in the western Canadian Arctic at varying depths (30-350 m) during ice-free seasons over a period of five years (2018-2022) has been conducted. The measured noise level correlates well with wind speed after the removal of contaminated (sources other than wind) noise data. The characteristics of wind noise are predicted by fitting a multi-parameter empirical model to data. Results from the model are compared with existing empirical wind noise models and validated using data collected from one of the measurement locations.

This study validates a fast measure for spatial release from masking-minimum angular separation (MAS), the smallest spatial separation between a target and two-talker maskers to improve speech intelligibility by 20%. Three psychophysical methods to estimate MAS were compared, including the constant stimuli, adaptive staircase, and progressive tracking, which revealed no significant difference in the estimated threshold on the group level with bootstrapping. Results suggest that the MAS measurement can be expedited using the progressive tracking method without compromising robustness in the threshold estimation. The non-linear relationship between target-masker spatial separation, signal-to-noise ratio, and accuracy is explored.

The reciprocity principle is widely used for acoustic measurements, including three-dimensionally printed waveguide transfer functions. Previous studies revealed unexpected deviations in the 1-4 kHz range, likely due to secondary transmission paths. This study tests the effectiveness of a sand layer in reducing these paths and evaluates measurement variability and robustness to harmonic distortion. The method, tested on an affected replica and two additional replicas, shows that the sand layer effectively minimizes secondary transmission paths. The measurement system proves robust against harmonic distortion, ensuring good reproducibility, with results compared to simulations for validation.