Subjects -> PHYSICS (Total: 857 journals)
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SOUND (25 journals)

Showing 1 - 22 of 22 Journals sorted alphabetically
Acoustical Physics     Hybrid Journal   (Followers: 13)
Acoustics     Open Access   (Followers: 4)
Acoustics Australia     Hybrid Journal   (Followers: 1)
Acoustics Today     Hybrid Journal   (Followers: 9)
Acta Acustica     Open Access   (Followers: 4)
Advances in Acoustics and Vibration     Open Access   (Followers: 48)
Applied Acoustics     Hybrid Journal   (Followers: 36)
Archives of Acoustics     Open Access   (Followers: 22)
Australasian Journal of Ultrasound in Medicine (AJUM)     Hybrid Journal   (Followers: 3)
Bioacoustics : The International Journal of Animal Sound and its Recording     Partially Free   (Followers: 5)
Building Acoustics     Hybrid Journal   (Followers: 4)
Bulletin de l'AFAS     Open Access   (Followers: 1)
Journal of Sound and Vibration     Hybrid Journal   (Followers: 155)
Journal of the Acoustical Society of America     Full-text available via subscription   (Followers: 58)
Journal of Ultrasonography     Open Access   (Followers: 1)
Journal of Ultrasound in Medicine     Full-text available via subscription   (Followers: 12)
Open Journal of Acoustics     Open Access   (Followers: 23)
Phonica     Open Access  
Proceedings of Meetings on Acoustics     Open Access   (Followers: 14)
Sonography     Hybrid Journal   (Followers: 1)
SoundEffects - An Interdisciplinary Journal of Sound and Sound Experience     Open Access   (Followers: 4)
Ultrasound International Open     Open Access   (Followers: 2)
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Proceedings of Meetings on Acoustics
Number of Followers: 14  

  This is an Open Access Journal Open Access journal
ISSN (Print) 1939-800X
Published by ASA Homepage  [2 journals]
  • Assessment of Computational Fluid Dynamics acoustic prediction accuracy
           and deflector impact on launch aero-acoustic environment

    • Authors: Mara Salut Escarti-Guillem, Luis M. Garcia-Raffi, Sergio Hoyas, Oliver Gloth
      Abstract: Proceedings of Meetings on Acoustics, Volume 50, Issue 1, December 2022.
      The vibroacoustic loading generated during the launch of space vehicles can cause the failure of electronic and mechanical components. Therefore, predicting and mitigating these vibroacoustic levels are crucial to improve the reliability of launchers and payload comfort. Because a properly designed flame deflector can significantly reduce the acoustic pressure level, the aeroacoustics characteristics of diverse types of flame deflectors must be understood. Three different deflector geometries have been analysed: two wedge-type deflectors and a flat deflector since the impact on a flat plate is the simplest case of reflection. The sound generation and propagation were studied using dedicated computational fluid dynamics. Additionally, experimental data has been used to evaluate the accuracy and performance of two numerical models. On the one hand, an Unsteady Reynolds-Averaged Navier-Stokes model running in central processing units, CPU. On the other hand, a Large Eddy Simulation model efficiently designed to run on graphics processing units, GPU. The second model showed excellent agreement at a low computational cost. To assess noise generation, the main shock waves were identified, and the evolution of the generated sound pressure was assessed. Moreover, the sound pressure levels at the fairing surface have been studied.
      Citation: Proceedings of Meetings on Acoustics
      PubDate: 2023-03-27T03:49:47Z
      DOI: 10.1121/2.0001716
  • Lenition measures: Neural networks’ posterior probability vs.
           acoustic cues

    • Authors: Ratree Wayland, Kevin Tang, Fenqi Wang, Sophia Vellozzi, Rahul Sengupta
      Abstract: Proceedings of Meetings on Acoustics, Volume 50, Issue 1, December 2022.
      A phonologically informed neural network approach, Phonet, was compared to acoustic measurements of intensity, duration and harmonicity in estimating lenition degree of voiced and voiceless stops in a corpus of Argentine Spanish. Recurrent neural networks were trained to recognize phonological features [sonorant] and [continuant]. Their posterior probabilities were computed over the target segments. Relative to most acoustic metrics, posterior probabilities of the two features are more consistent, and in the direction predicted by known factors of lenition: stress, voicing, place of articulation, surrounding vowel height, and speaking rate. The results suggest that Phonet could more reliably quantify lenition gradient than some acoustic metrics.
      Citation: Proceedings of Meetings on Acoustics
      PubDate: 2023-03-27T03:46:21Z
      DOI: 10.1121/2.0001728
  • Directional passive acoustic structures inspired by the ear of Achroia

    • Authors: Lara Díaz-García, Andrew Reid, Joseph Jackson-Camargo, James Windmill
      Abstract: Proceedings of Meetings on Acoustics, Volume 50, Issue 1, December 2022.
      The need for small directional microphones is patent in the current market. From smartphones to hearing aids, a small microphone capable of rejecting ambient noise is highly desirable. Most MEMS microphones are omnidirectional and have to resort to arrays to achieve directionality, effectively counteracting the reduced size that they offer in the first place. For this reason, we use bio-inspiration and turn to nature to find examples of solutions to this problem. The female specimens of the moth Achroia grisella are capable of monoaural directional hearing, which they use to track the males’ mating calls. It is believed that they achieve directionality solely due to the morphology of their tympana. To test it, we first produce a multiphysics simulation of the structure that serves as a starting point. For experimental measurements, additive manufacturing is chosen for its ease and cost-efficiency. 3D-printed samples of the same model are examined through micro-CT scanning and then measured using laser-Doppler vibrometry to determine their frequency and directivity responses. The results of both approaches are compared, and it is found that the structure does indeed show directionality and the experimental and simulated results are in good agreement.
      Citation: Proceedings of Meetings on Acoustics
      PubDate: 2023-03-23T07:13:52Z
      DOI: 10.1121/2.0001715
  • Marine mammal permanent threshold shift prediction from down-the-hole
           piling noise exposure using kurtosis

    • Authors: Shane Guan
      Abstract: Proceedings of Meetings on Acoustics, Volume 50, Issue 1, December 2022.
      In assessing auditory effects on marine mammals from sound exposure, regulators currently estimate noise-induced threshold shifts (NITSs) based on classifying anthropogenic sound in two mutually exclusive categories: impulsive or non-impulsive. However, in real-world situations, marine mammals are often exposed to complex sound fields containing both impulsive and non-impulsive components, making it difficult or even impossible to accurately assess NITSs from sound exposure. One example of complex sound originates from down-the-hole (DTH) pile installation, which generates both impulsive sound from percussive drilling/striking and non-impulsive sound from simultaneous debris removal. This study employed a relatively simple approach of using kurtosis values to quantify the impulsiveness of two DTH pile installation datasets for six different marine mammal functional hearing groups. A kurtosis adjustment approach was then used—one that has been suggested to be able to predict human hearing loss from sound exposure—to calculate the correction factors for estimating NITSs of marine mammals exposed to DTH piling sound. Fur-ther research on marine mammal NITSs from complex sound exposure is needed to validate and improve this model.
      Citation: Proceedings of Meetings on Acoustics
      PubDate: 2023-03-23T07:09:52Z
      DOI: 10.1121/2.0001727
  • Uncovering the differences between the violin and erhu musical instruments
           by statistical analysis of multiple musical pieces

    • Authors: Wenyi Song, Andrew Brian Horner
      Abstract: Proceedings of Meetings on Acoustics, Volume 50, Issue 1, December 2022.
      The violin and erhu are two of Western and Chinese music’s main bowed string instruments. Recent work has compared the different emotional characteristics between the violin and erhu on the Butterfly Lovers Concerto. In our study, we examine several hypotheses to investigate whether the previous studies’ results hold generally. Four musical excerpts were extracted from four famous Chinese and Western classical pieces, and the excerpts were divided into four emotional categories: Happy, Sad, Agitated, and Calm. Based on the Butterfly Lovers results, we expected that: (1) the violin has a more Happy emotional characteristic than the erhu, while the erhu is comparatively more Sad, and (2) the violin is better at conveying high-Arousal excerpts. We used the Bradley-Terry-Luce (BTL) paired-comparison model to obtain the ranking scores and identify statistically significant differences between the two instruments. The erhu was consistently perceived as sadder than the violin for all Sad excerpts, while the violin was generally calmer and more agitated for those categories. Further study with more listeners and excerpts is needed to verify whether these results generally hold and at a statistically significant level.
      Citation: Proceedings of Meetings on Acoustics
      PubDate: 2023-03-22T07:18:18Z
      DOI: 10.1121/2.0001710
  • Applying unsupervised machine learning clustering techniques to early
           childcare soundscapes

    • Authors: Kenton Hummel, Erica Ryherd, Iason Konstantzos, Abbie Raikes
      Abstract: Proceedings of Meetings on Acoustics, Volume 50, Issue 1, December 2022.
      Early childhood is a critical time period for language, brain, cognitive, and social/emotional development. Out-of-home childcare is a normative, typical experience for millions of young children. Although Indoor Environmental Quality (IEQ) in K-12 settings has received recent, significant attention, the links between IEQ and children's learning and development in early childcare settings is a less understood topic. This work focuses specifically on the sound aspect of IEQ in early childcare settings to better understand typical noise levels and occupant experience. Standard approaches to analyzing background noise will be presented alongside more detailed statistical analyses utilizing unsupervised machine learning clustering techniques. Noise data collected in three daycares will be presented using typical acoustic metrics and clustering techniques to better understand room activity conditions and support new metrics. Overall, this study can lead to a better understanding of daycare soundscapes and pave the way towards a better childcare for young children.
      Citation: Proceedings of Meetings on Acoustics
      PubDate: 2023-03-22T07:10:17Z
      DOI: 10.1121/2.0001708
  • Emotion Equalization App: A First Study and Results

    • Authors: Man Hei Law, Andrew Brian Horner, Hoi Ting Leung
      Abstract: Proceedings of Meetings on Acoustics, Volume 50, Issue 1, December 2022.
      In recent years, there is an increasing trend of mental health issues in society. It is important to identify mental first aid strategies that can be applied at an early age, whether emotional issues have been diagnosed or have yet to be found. Music has tremendous potential impact on changing emotional states since it can distract listeners from rumination on negative thoughts and engage them in a moment of musical enjoyment.This paper presents a new emotion equalization app that incorporates validated diagnosis tests (PHQ-9 and GAD-7) and an emotion measuring tool (SAM) for establishing a personalized therapy treatment using emotion rebalancing methods. By determining the emotional state of the user, songs are chosen and sequenced in a playlist using one of three proposed methods (consoling, relaxing, and uplifting) with a baseline method (random). With this systematic generation of playlists, the app can be used for personalized therapeutic treatment even for users without music background. In our experiment, the results showed positive changes in listeners’ valence levels while there was no significant change in arousal. Further, the relaxing and uplifting methods showed a significant effect on moving listeners from negative to more positive emotional states.
      Citation: Proceedings of Meetings on Acoustics
      PubDate: 2023-03-22T07:04:38Z
      DOI: 10.1121/2.0001701
  • Measuring and Exploiting the Locally Linear Mapping between Relative
           Transfer Functions and Array deformations

    • Authors: Kanad Sarkar, Manan Mittal, Ryan Corey, Andrew Singer
      Abstract: Proceedings of Meetings on Acoustics, Volume 50, Issue 1, December 2022.
      Large-scale distributed arrays can obtain high spatial resolution, but they typically rely on a rigid array structure. If we want to form distributed arrays from mobile and wearable devices, our models need to account for motion. The motion of multiple microphones worn by humans can be difficult to track, but through manifold techniques we can learn the movement through its acoustic response. We show that the mapping between the array geometry and its acoustic response is locally linear and can be exploited in a semi-supervised manner for a given acoustic environment. Prior work has shown a similar locally linear mapping between source locations and their spatial cues, and we implement a semi-supervised model originally used with source localization for dynamic array geometries.
      Citation: Proceedings of Meetings on Acoustics
      PubDate: 2023-03-22T06:58:18Z
      DOI: 10.1121/2.0001707
  • Low-frequency directional characteristics of a gamelan gong

    • Authors: Samuel David Bellows, Dallin T. Harwood, Kent L. Gee, Timothy W. Leishman
      Abstract: Proceedings of Meetings on Acoustics, Volume 50, Issue 1, December 2022.
      The structural modes of gamelan gongs often have clear impacts on their far-field directivity patterns with the number of directional lobes corresponding to the associated structural mode shapes. Many of the lowest modes produce dipole-like radiation with the dipole moment determined by the positions of the nodal and antinodal regions. Spherical harmonic and multipole expansions facilitate further understanding of the gongs’ low-frequency directional characteristics. The expansions also yield practical simplifications to model their radiation.
      Citation: Proceedings of Meetings on Acoustics
      PubDate: 2023-03-14T06:43:07Z
      DOI: 10.1121/2.0001722
  • Estimating bubble size in Lake Kinneret through reflection of wideband
           sound signals from gas-rich sediment environment

    • Authors: Ernst Uzhansky, Boris Katsnelson, Andrey Lunkov, Regina Katsman, Anatoliy Ivakin
      Abstract: Proceedings of Meetings on Acoustics, Volume 50, Issue 1, December 2022.
      Gas-rich sediments cause permanent concern due to their contribution to sediment destabilization and global warming. In this paper, an effective media theory of gassy sediments previously suggested by the authors is tested experimentally in Lake Kinneret using wideband acoustic signals. Results of experiments and the corresponding acoustic data processing is presented. Ten 5-s long wideband (0.3-15 kHz) chirp pulses were radiated by an underwater transducer mounted directly at a 30-m long seven-channel vertical line array (VLA) deployed in the central part of the lake (the seafloor depth is 35 m). Received sound field timeseries consists of a sequence of pulse arrivals comprised of specular reflections from interfaces followed by reverberation codas caused by non-specular scattering from the interface roughness and volume inhomogeneity. Having studied the frequency dependence of the signal reflected from the bottom, a dip in the reflection coefficient was found at frequencies of 4-6 kHz. This suggests the existence of bubbles with an effective spherical diameter of about 3 mm, which is consistent with previous direct measurements of bubbles in the lake sediments.
      Citation: Proceedings of Meetings on Acoustics
      PubDate: 2023-03-10T07:05:27Z
      DOI: 10.1121/2.0001721
  • Virtual acoustic reconstruction of the Roman amphitheater of Avella, Italy

    • Authors: Umberto Berardi, Antonella Bevilacqua, Gino Iannace, Amelia Trematerra
      Abstract: Proceedings of Meetings on Acoustics, Volume 50, Issue 1, December 2022.
      In ancient Rome, gladiator fights were very popular. The places where these shows took place were called amphitheaters, due to the particular shape of the elliptical building. Amphitheaters were constructed in every city. This paper describes the virtual acoustic reconstruction of the amphitheater of Avella, located near Naples, Italy. The amphitheater, discovered several decades ago and partially reconstructed, is now used for musical performances during the summer season. Acoustic measurements were carried out and the main acoustic parameters were determined according to the standard ISO 3382. Based on the dimensions and geometries of similar architectures of other amphitheaters, a virtual reconstruction of the original shape was performed. The virtual model was developed using Ramsete architectural acoustics software to obtain the acoustic characteristics of the amphitheater as it was in the Roman period. In particular, the spatial distribution of the acoustic properties on the cavea where the spectators sat is described and discussed.
      Citation: Proceedings of Meetings on Acoustics
      PubDate: 2023-03-09T07:54:21Z
      DOI: 10.1121/2.0001720
  • Effect of acoustic low frequency ultrasound parameters on the reflected
           signal from a rigid porous medium

    • Authors: Mustapha Sadouki, Abdelmadjid Mahiou, Nacera Souna
      Abstract: Proceedings of Meetings on Acoustics, Volume 50, Issue 1, December 2022.
      There are several parameters describing the porous medium that play an important role on the attenuation of the acoustic wave propagating in such biphasic mediums. These parameters are classified in two categories: high frequency parameters and low frequency parameters. During the excitation by an acoustic wave, two cases can occur; the vibration of both phases simultaneously, the structure and the saturating fluid, in the case where the structure is flexible. This last case is well described by the theory of Biot. For a rigid structure, it is the movement of the fluid that is taken into account; this last case is treated by the equivalent fluid theory which is a particular case of Biot theory. Previous work [Proc. Mtgs. Acoust. 45, 045004 (2021)] has shown the influence of the parameters involved in the corrected Johnson-Allard model recently introduced by Sadouki [Phys. Fluids 33, (2021)] on the signal transmitted by a rigid-porous material in the low frequency regime of ultrasound. The objective of this work is to show, once again, the influence of these same parameters on the reflected signal by proposing a comparative study between the transmitted and reflected modes.
      Citation: Proceedings of Meetings on Acoustics
      PubDate: 2023-03-09T07:52:01Z
      DOI: 10.1121/2.0001717
  • Mismatch negativity linked with sound lateralization in elderly

    • Authors: Kazumoto Morita, Moeko Shiroki, Sunao Iwaki, Takeshi Tois
      Abstract: Proceedings of Meetings on Acoustics, Volume 50, Issue 1, December 2022.
      Elderly individuals tend to experience a decline in auditory functions. One of these is poor lateralization ability. This study aimed to investigate the relationship between sound lateralization and mismatch negativity (MMN) in elderly individuals using a lateralization test and event-related potential (ERP) measuring test. In the lateralization test, participants were presented with sound stimuli with an interaural time difference (ITD) in the right or left ear and were required to indicate the sound direction. The ERP measuring test estimated unconscious brain activity during participants’ exposure to sound stimuli using an ITD in the right or left ear. Two ITDs (i.e., 0.4 ms and 0.8 ms) of a 1-kHz pure tone were measured in elderly and young participants. For sounds with phase reversal between the onset and ongoing parts, young individuals performed lateralization based on the onset part. In contrast, at an ITD of 0.8 ms, elderly participants unable to perceive the onset part tended to demonstrate less negative MMN. In conditions where the preceding ear in onset and ongoing parts was reversed, elderly participants exhibited ambiguous lateralization, and their cortical evoked potentials did not significantly differ from activity associated with standard stimuli without an ITD.
      Citation: Proceedings of Meetings on Acoustics
      PubDate: 2023-03-07T06:33:57Z
      DOI: 10.1121/2.0001719
  • Highly damped single-chamber pneumatic vibration isolator using effects of
           thermal conductivity in the air volume

    • Authors: Vyacheslav Ryaboy
      Abstract: Proceedings of Meetings on Acoustics, Volume 50, Issue 1, December 2022.
      Contemporary pneumatic isolators have dual-chamber design with metered orifices between the chambers. This arrangement produces the energy dissipation necessary to avoid excessive resonance vibration. However, this leads to reduced isolation performance compared to a single-chamber isolator of equivalent total volume. Analysis shows that, while the dynamic process of the air compression in the pneumatic chamber is adiabatic for geometric parameters usually employed in vibration isolators, substantial dissipation of mechanical energy can be achieved by introducing certain thermally conductive features into the chamber. That makes practical a single-chamber design with sufficient damping. The paper presents the optimization of the geometry of thermally conductive features aimed at maximizing the loss factor at the resonance frequency of the isolation system. Experimental results illustrate the concept and demonstrate the increased isolation effect.
      Citation: Proceedings of Meetings on Acoustics
      PubDate: 2023-03-01T08:25:19Z
      DOI: 10.1121/2.0001714
  • Comparison of the emotional characteristics of western orchestral
           sustaining musical instrument families with different pitch and dynamics

    • Authors: Hiu Ting Chan, Bing Yen Chang, Andrew Brian Horner, Man Hei Law
      Abstract: Proceedings of Meetings on Acoustics, Volume 50, Issue 1, December 2022.
      Recent research has shown that the emotional characteristics of the bowed strings and brass change with different pitch and dynamics. This work compares how pitch and dynamics influence their characters in the western orchestral sustaining musical instruments. We conducted listening tests where listeners gave absolute judgements on the sounds over ten emotional categories and analyzed the data with logistic regression. For pitch, the categories Happy and Heroic had an arched shape that peaked at C6. Romantic, Calm, and Shy increased until C4 and decreased afterwards. Comic and Mysterious did not shown a clear common trend with pitch. Angry and Scary had a U-shape that was slightly stronger at the highest pitch, while Sad decreased with pitch. For dynamics, Happy, Heroic, Comic, and Angry were stronger for loud notes, while Romantic, Calm, Mysterious, Shy, and Sad were stronger for soft notes. For Scary, loud and soft notes were about the same. In the bowed strings and woodwinds, pitch and dynamics had about an equally important effect on the emotional characteristics, while pitch had a more important effect than dynamics in the brass. For the bowed strings, brass, and woodwinds, the particular instrument was more of a secondary factor though still important.
      Citation: Proceedings of Meetings on Acoustics
      PubDate: 2023-03-01T08:23:59Z
      DOI: 10.1121/2.0001712
  • The effects of vowel, pitch and dynamics on the emotional characteristics
           of the SATB voices

    • Authors: Bing Yen Chang, Man Hei Law, Hiu Ting Chan, Andrew Horner
      Abstract: Proceedings of Meetings on Acoustics, Volume 50, Issue 1, December 2022.
      Previous research on the soprano and tenor voices have shown that their emotional characteristics change with different vowel, pitch, and dynamics. This work continues the investigation with the alto and bass voices. Listening tests were conducted whereby listeners gave absolute judgements on the SATB voice tones over ten emotional categories, with the data analyzed using logistic regression. High-arousal categories were stronger for loud tones, whereas low-arousal categories were stronger for soft tones. The categories Happy, Heroic, Romantic, and Shy had mostly upward trends across the pitch range, whereas Angry had an overall downward trend. Calm and Sad had an arch-shaped trend, while Scary had a U-shaped trend. Comic and Mysterious had different trends among the voices. The voices each exhibited different vowel trends, though vowel A was dominant for all the voice types in the categories Happy and Romantic. Dynamics had the strongest effect overall, followed closely by pitch, with both effects approximately twice as strong as the effect of vowel. Vowel U had the largest strength-of-expressiveness overall, with A second, O third, I fourth, and finally E last. These results give a quantified preliminary perspective on how vowel, pitch, and dynamics shape emotional expression in the SATB voices.
      Citation: Proceedings of Meetings on Acoustics
      PubDate: 2023-02-28T06:19:02Z
      DOI: 10.1121/2.0001711
  • Infrasound and Internal Gravity Waves generated by Meteorological Fronts

    • Authors: Igor Chunchuzov, Sergey Kulichkov, Oleg Popov, Vitaly Perepelkin, Arman Vardanyan, Gagik Ayvazyan
      Abstract: Proceedings of Meetings on Acoustics, Volume 50, Issue 1, December 2022.
      The results of study of temporal variations of the characteristics of infrasound and internal gravity waves (amplitudes, coherences, grazing angles, azimuths and horizontal phase speeds) detected during a passage of warm and cold fronts through the networks of microbarometers installed in the Moscow region and Armenia (city Talin) are presented. Infrasound radiated during periods of weather changes is an almost continuous background against which infrasound monitoring of explosions in the atmosphere is carried out. The significant differences were observed in the characteristics of infrasound from warm and cold fronts. Such differences must be taken into account when detecting infrasound precursors of atmospheric storms. A possible aerodynamic mechanism for the generation of infrasound caused by the turbulent air flow around the geometric irregularities of the surface of meteorological front is proposed.
      Citation: Proceedings of Meetings on Acoustics
      PubDate: 2023-02-28T06:09:42Z
      DOI: 10.1121/2.0001713
  • Prosody Analysis as a Tool for Differential Diagnosis of Cognitive

    • Authors: Chorong Oh, Richard J. Morris, Xianhui Wang
      Abstract: Proceedings of Meetings on Acoustics, Volume 50, Issue 1, December 2022.
      This study was conducted to determine whether acoustic analysis of speech prosody can assist in differential diagnosis of cognitive impairment. Speech samples describing the Cookie Theft picture were obtained from the DementiaBank and analyzed acoustically using 22 speech prosody features via the Praat software. Included in this speech dataset were 10 people with dementia of the Alzheimer’s type, 9 people with mild cognitive impairment, 5 people with vascular dementia, and 10 neurologically healthy controls. The principal components analysis, and Mahalonabis distance tests revealed that using acoustic measures of speech prosody may be a functional method for differential diagnosis of the cognitive impairment types.
      Citation: Proceedings of Meetings on Acoustics
      PubDate: 2023-02-21T03:32:22Z
      DOI: 10.1121/2.0001709
  • Microphone vibration sensitivity: what it is, why it is important, and how
           to measure it

    • Authors: Charles B. King, Chris Monti
      Abstract: Proceedings of Meetings on Acoustics, Volume 50, Issue 1, December 2022.
      Microphones are designed to respond to acoustic pressure fields, but they can also be excited by external sources of mechanical vibration. In hearing aids, feedback is a difficult problem to resolve due to the high gain used to amplify sounds. The problem is worsened by the location of microphones and loudspeakers in close proximity, coupling both the acoustic and mechanical feedback paths. The first proposals of microphone vibration measurement techniques and definitional structure were published by Mead Killion in the 1970’s. Significant improvements in measurement technique have been published over the last 10 years. This talk will focus on a new measurement technique that allows for direct measurement of the “intrinsic vibration sensitivity.” The technique gives the ideal zero acoustic pressure condition at the microphone port and isolates room acoustic noise from the desired vibration signal. The noise floor of the new technique is 30dB below Z axis measurement, allowing for exceptionally clean measurement of primary-axis vibration sensitivity up to 10 kHz. Improvements are robust enough to enable the clean measurement of off-axis sensitivity of the microphone, which is often below 50 dB SPL equivalent at 9.81 m/s^2 of acceleration.
      Citation: Proceedings of Meetings on Acoustics
      PubDate: 2023-02-14T07:26:01Z
      DOI: 10.1121/2.0001702
  • Salinity, force chains and creep in muddy sediments

    • Authors: Nicholas P. Chotiros
      Abstract: Proceedings of Meetings on Acoustics, Volume 50, Issue 1, December 2022.
      The salinity of sediments is not usually measured. Experience with sandy sediments shows that it has no significant effect on the acoustic properties. In muddy sediments, salinity is critical to the skeletal frame, because it causes the clay particles to flocculate, forming an aggregate of larger particles with significant water fraction. It behaves like a granular medium, in which stress is transmitted along random force chains. Mud is known to suffer from creep, and the force chain model fits neatly into creep theory. It may be modeled as a form of stationary creep, which is linear in many respects. No net strain-hardening is involved. The result is a creep model of the skeletal frame that naturally couples into the Biot theory of porous media. It predicts an attenuation that increases linearly with frequency at low frequencies, which is overtaken by viscous attenuation that increases as the second power of frequency and high frequencies. Using the generalized squirt flow model, both sandy and muddy sediments may be modeled by the same set of equations, which opens up the prospect of a universal model for marine sediments that can cover a wide range of sediment types over a broad range of frequencies.
      Citation: Proceedings of Meetings on Acoustics
      PubDate: 2023-02-14T07:24:02Z
      DOI: 10.1121/2.0001699
  • Suppressing reverberation in cochlear implant stimulus patterns using
           time-frequency masks based on phoneme groups

    • Authors: Kevin Chu, Leslie Collins, Boyla Mainsah
      Abstract: Proceedings of Meetings on Acoustics, Volume 50, Issue 1, December 2022.
      Cochlear implant (CI) users experience considerable difficulty in understanding speech in reverberant listening environments. This issue is commonly addressed with time-frequency masking, where a time-frequency decomposed reverberant signal is multiplied by a matrix of gain values to suppress reverberation. However, mask estimation is challenging in reverberant environments due to the large spectro-temporal variations in the speech signal. To overcome this variability, we previously developed a phoneme-based algorithm that selects a different mask estimation model based on the underlying phoneme. In the ideal case where knowledge of the phoneme was assumed, the phoneme-based approach provided larger benefits than a phoneme-independent approach when tested in normal-hearing listeners using an acoustic model of CI processing. The current work investigates the phoneme-based mask estimation algorithm in the real-time feasible case where the prediction from a phoneme classifier is used to select the phoneme-specific mask. To further ensure real-time feasibility, both the phoneme classifier and mask estimation algorithm use causal features extracted from within the CI processing framework. We conducted experiments in normal-hearing listeners using an acoustic model of CI processing, and the results showed that the phoneme-specific algorithm benefitted the majority of subjects.
      Citation: Proceedings of Meetings on Acoustics
      PubDate: 2023-02-08T03:42:40Z
      DOI: 10.1121/2.0001698
  • Inferring pitch from coarse spectral features

    • Authors: Danni Ma, Neville Ryant, Mark Liberman
      Abstract: Proceedings of Meetings on Acoustics, Volume 50, Issue 1, December 2022.
      Fundamental frequency (F0) has long been treated as the physical definition of "pitch" in phonetic analysis. But there have been many demonstrations that F0 is at best an approximation to pitch, both in production and in perception: pitch is not F0, and F0 is not pitch. Changes in the pitch involve many articulatory and acoustic covariates; pitch perception often deviates from what F0 analysis predicts; and in fact, quasi-periodic signals from a single voice source are often incompletely characterized by an attempt to define a single time-varying F0. In this paper, we find strong support for the existence of covariates for pitch in aspects of relatively coarse spectra, in which an overtone series is not available. Thus linear regression can predict the pitch of simple vocalizations, produced by an articulatory synthesizer or by human, from single frames of such coarse spectra. Across speakers, and in more complex vocalizations, our experiments indicate that the covariates are not quite so simple, though apparently still available for more sophisticated modeling. On this basis, we propose that the field needs a better way of thinking about speech pitch, just as celestial mechanics requires us to go beyond Newton’s point mass approximations to heavenly bodies.
      Citation: Proceedings of Meetings on Acoustics
      PubDate: 2023-02-08T03:41:00Z
      DOI: 10.1121/2.0001696
  • Piezoelectric finite-difference time-domain simulation of piezoelectric
           signals generated in cancellous bone by ultrasound irradiation

    • Authors: Atsushi Hosokawa
      Abstract: Proceedings of Meetings on Acoustics, Volume 50, Issue 1, December 2022.
      Bone formation can be driven by mechanical loads applied to the bone. By taking advantage of this mechanism, the accelerated healing of bone fracture using low-intensity pulsed ultrasound (LIPUS) has been medically practiced. Bone can behave as a piezoelectric material, and the piezoelectric effects are considered to accompany the bone formation. However, the piezoelectric properties in bone, particularly in cancellous bone with a porous structure, at ultrasound frequencies are too complex to easily clarify. In such a case, numerical simulations can be helpful because they enable visualization in the “black box”. Numerical simulations by an elastic finite-difference time-domain (FDTD) method have been widely performed to investigate ultrasound behaviors in bone. In this study, the elastic FDTD method with piezoelectric constitutive equations (PE-FDTD method) was used to simulate the piezoelectric signals generated in water-saturated cancellous bone by ultrasound irradiation. The cubic cancellous bone model was reconstructed from the X-ray microtomographic image. The piezoelectric signal waveforms when an ultrasound burst wave was irradiated in three orthogonal directions were calculated, together with the ultrasound signal waveforms propagated through cancellous bone. From the calculated results, the effect of the trabecular orientation was investigated.
      Citation: Proceedings of Meetings on Acoustics
      PubDate: 2023-02-08T03:35:32Z
      DOI: 10.1121/2.0001693
  • A dual sampling-rate active noise equalization algorithm for active sound
           quality control of vehicle interior noise

    • Authors: Shuai Zhang, Lijun Zhang, Dejian Meng
      Abstract: Proceedings of Meetings on Acoustics, Volume 50, Issue 1, December 2022.
      In-vehicle active sound quality control (ASQC) system is an advanced application of active noise control (ANC) technology, which always suppresses the interior sound pressure or improves the psychoacoustic features. However, the connection between the sound quality control state and the vehicle’s working state is normally ignored. The passenger’s sound perception typically expects a linear relationship between the vehicle speed and sound loudness. Therefore, this paper presents a dual sampling-rate active noise equalization algorithm. The low sampling-rate signal is used to improve system computing efficiency, the high sampling-rate signal is used to improve the ASQC effect. Their conversion communication uses a zero-order hold (low to high) and a re-sampler (high to low). The data relating to the ASQC system was collected, and some sound quality evaluations were conducted for determining two appropriate sampling-rate values. Combining a genetic algorithm and the corresponding ASQC simulation system, the algorithmic optimal gain coefficients were further determined at different engine speeds. The verification results of ASQC using this proposed algorithm show that the sound quality of interior noise is effectively suppressed; the nonlinear index is reduced to 1.33, improving by 37% relative to the original noise and by 20% compared to the ANC system.
      Citation: Proceedings of Meetings on Acoustics
      PubDate: 2023-02-08T03:29:55Z
      DOI: 10.1121/2.0001694
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