bluuebunny/crossref_metadata_2025 huggingface dataset:
Mid-frequency acoustic localization of breaking waves
Authors: Saenger Ryan , Lenain Luc , Kuperman William , Hodgkiss William
Published: April 2023

During an experiment in deep water off the coast of Southern California, winds between 20 and 25 knots resulted in large breaking waves. A mid-frequency planar hydrophone array recorded underwater ambient noise while an airplane equipped with a high-resolution video camera recorded images of the sea surface above the array. Beams of ambient noise between 5 and 6kHz were projected onto the sea surface and aligned in space and time with the aerial images. The array’s resolution of the surface is coarse (20 by 50 m) due to its modest 1 meter horizontal aperture and relatively deep 130meter deployment depth. Nonetheless, concentrated regions of high intensity in the acoustic surface projection match visible breaking events in the aerial images. [Work supported by the Office of Naval Research.]
Dynamics of focused ultrasound-enhanced glymphatic transportation in the mouse brain
Authors: Gong Yan , Xu Kevin , Ye Dezhuang , Yang Yaoheng , Chen Hong
Published: April 2023

The glymphatic system, a perivascular network in the brain, regulates the exchange of cerebrospinal fluid and interstitial fluid in the perivascular space. Focused ultrasound combined with microbubbles (FUSMB) has been recently shown feasible to manipulate the glymphatic transportation by enhancing the intranasal delivery of agents in the perivascular space. The objective of this study was to reveal the dynamics of FUSMB-enhanced agent transport in the glymphatic system. A ring-shaped FUS transducer was confocally aligned with an objective of a two-photon microscope (2PM). Fluorescently labeled albumin was administered to the mouse nose, where it transported along olfactory nerve and trigeminal nerve from nose to brain and then spread in perivascular space in the brain. FUS sonication was performed after intravenous injection of microbubbles. In vivo 2PM recorded the dynamics of agent transportation before, during, and after FUS sonication. Time-lapse recording showed that FUSMB enhanced the agent accumulation at the perivascular space. FUS significantly increased the accumulation of the agent in the perivascular space by 1.2-folds immediately after the sonication (p = 0.0325), and 1.6-folds at 5 min after the sonication (p < 0.0001). In conclusion, this study showed, for the first time, direct evidence of FUSMB-enhanced glymphatic transportation in the mouse brain.
Progress in understanding seismic wind noise
Authors: Raspet Richard , Hickey Craig J. , Samad Md. A.
Published: April 2023

Previous work at NCPA on predicting and measuring wind noise in the ground used a quasistatic calculation employing Shield’s wind noise correlation function. This method predicted the vertical displacements at the surface well, but under predicted the horizontal displacement and predicted a rapid decay of levels with depth that was not observed in the measurements. A new measurement of the wind noise correlation coefficients using flush mount microphones was presented at the Seattle Meeting (2aPa1). In this talk additional measurements and improved methods for evaluating the coefficients are described. An improved calculation of the seismic levels due to wind induced pressures at the ground has been developed based on the wavenumber-frequency analysis developed for studying airframe noise due to turbulence. This calculation correctly predicts the surface vertical component and the near constant seismic level in the first 40cm of the ground. It still under predicts the horizontal component, but the under prediction is smaller than that predicted by the quasistatic calculation. [This research was sponsored by the Department of the Navy, Office of Naval Research under ONR Award No. N00014-18-2489.]
Optimized directionality in acoustically coupled, dual motor, uniphase, moving coil microphones
Authors: Grinnip Roger
Published: April 2023

In uniphase, moving coil microphones, pneumatic vibration cancellation is an effective means to minimize structural excitation. However, pneumatic vibration cancellation requires precise control of the transfer function between the capsule and the microphone body, and the internal volumes are large. Therefore, the uniphase, moving coil capsule with pneumatic vibration cancellation is not well suited as a portable platform in applications that require a compact size. The addition of a secondary transduction mechanism is commonly used to mitigate a variety of unwanted signal sources in microphones, and is an effective alternative to the pneumatic vibration cancellation. Because the secondary transduction mechanism is integral to the capsule, precise control of the capsule/body transfer function is not needed, resulting in a more portable solution. However, the current strategy for vibration cancellation is to isolate the secondary transduction mechanism from the acoustical excitation, which does not minimize the internal volume and is not compact. A new strategy proposes an alternative architecture where the two transduction mechanisms share an internal volume. When certain constraints are met, acoustically coupling the motors results both a minimized internal volume and an optimized microphone directionality at low frequencies. Simulated and measured results are shown to illustrate the implementation.
Novel design method for sub-miniature MEMS microphones with enhanced acoustic SNR
Authors: Pedersen Michael , Naderyan Vahid , Loeppert Peter
Published: April 2023

A well understood performance limitation in the conventional design of MEMS microphones relates to the dimensions of the back volume, which, along with the barometric vent, sets the ultimate limit of acoustic noise in the system, regardless of the microphone transduction principle. The acoustic noise in the back volume is generated from the heat flow within the thermal boundary layer near the isothermal walls. In this paper, a new and previously unused part of the back volume design space is explored, in which the primary loss mechanism is thermal (as opposed to viscous), and the effective thermal conductivity and heat capacitance of the gas in the volume is designed to achieve low acoustic noise in extremely small enclosures. In this new regime, the acoustic SNR in frequency bands of interest can be optimized to achieve values comparable or even larger than those in the conventional design space with much larger enclosures. The primary trade-off in design relates to achievable acoustic SNR versus necessary acoustic compliance with the selected transduction principle. Underlying principles and design examples are presented with supporting measurements from prototype devices, showing acoustic SNR in excess of 70 dB with a back volume of less than 0.2 mm3.
Longitudinal standing waves, mechanical waves, and diagnostics
Authors: Dostal Jack A.
Published: April 2023

The Standing Wave Diagnostic Test is a 22-item multiple choice survey designed to assess student understanding of longitudinal standing waves in air. I created it to measure my students’ difficulties with the subject. I also created the Longitudinal Standing Wave Tutorial to address these difficulties. The tutorial uses marked springs, tuning forks, pipes, and plenty of discussion to develop students’ understanding. Both the diagnostic and tutorial are based in physics education research and developed using survey and interview data from college physics classes. I often use the tutorial as a laboratory exercise in my Physics of Music class, which generates some interesting differences from the college physics classes. Some are a result of students’ prior knowledge about sound, while others are influenced by the course material covered prior to the tutorial. I will discuss some of my own results with these materials and put them in context with other physics education research based mechanical wave surveys.
Engaging students with team based and open-ended response projects in a descriptive acoustics course
Authors: Andersen Bonnie
Published: April 2023

Helping non-science majors feel comfortable in a physics class can be a challenge. Inclusive pedagogy techniques encourage creating learning communities and providing more opportunities for students to engage with the content. Elements of Team Based Learning (TBL) and open-ended response projects were applied to a descriptive acoustics course. TBL allows students to work with permanent, strategically placed teams during the semester. Teams are selected to help spread the abilities uniformly for all teams to be successful. In this course, group activities, a group component of exams, and the peer evaluation were implemented. The evaluation holds students accountable for their effects with their teams, rewarding students who work hard and minimize freeloading, an often-challenging aspect of group work. In addition to TBL, open-ended response projects were used in place of a research paper. Students can choose to research an acoustics topic or perform their own experiment. The students can also decide how they would like to present their work. The flexibility allowed students to display their results in a variety of ways from traditional written work to podcasts.
Applications of the psychoacoustic tonality method
Authors: Sottek Roland , Gomes Lobato Thiago Henrique
Published: April 2023

Psychoacoustic tonality calculated using the Sottek Hearing Model is an established method, standardized in ECMA 418-2 that can be used in various product assessments to identify and quantify prominent tonal components. The perception and evaluation of sound events containing such components has become increasingly important, e.g., in the field of vehicle acoustics to evaluate tonality due to alternative powertrains, or in information technology (IT) equipment due to hard disk noise. In addition, many products contain fans, e.g., IT equipment, household appliances, and air conditioning systems in buildings. Noticeable noise can emanate from these fans. However, there is no central publication describing most applications of the method, so its capabilities are not widely known. The goal of this article is to fill this gap by presenting the method clearly and concisely, and highlighting its various applications in industry. By providing a comprehensive overview of the method and its applications, we aim to help practitioners improve the quality of their audio designs by making them aware of the benefits of psychoacoustic tonality.
An air handling equipment manufacturer’s perspective on tonal noise measurement and application
Authors: Fly Mark W.
Published: April 2023

In order to reliably predict sound from HVAC equipment, including tonal noise, sound power data needs to be determined for each noise producing component in the equipment. Though there are accepted standards for determining broad band sound in resolutions no finer than one-third octaves, there is a general lack of component data regarding tonal characteristics. This noise produced by the HVAC system in indoor environments is often an important source of masking noise improving speech privacy and the overall acoustical environment. The presence of prominent tones that are propagated into the space is counter to creating comfortable acoustical environments. The primary HVAC noise source is the fan and all fans produce tones at the blade pass frequency and harmonics. There is currently no accepted standard method of test for the tonality of fan noise. This paper proposes a standard method that can consistently be used to determine the tonality of fan noise, which can in turn be used to determine if when combined with other self gen noise generated by the air distribution system to determine the prominence of tones that will propagate to the occupied space.
Radiation-induced acoustic imaging
Authors: Xiang Liangzhong S.
Published: April 2023

We explore new ways to generate ultrasound for medical diagnosis and treatment monitoring. Specifically, we use varies radiations (X-ray, proton, and electrical field) to treat diseases, simultaneously it will produce ultrasound waves for image-guided interventions. This talk will cover three primary research areas: (1) x-ray-induced acoustic computed tomography (XACT) for precision radiotherapy and radiology; (2) proton-induced acoustic imaging for proton therapy guidance; and (3) electroacoustic tomography (EAT) for irreversible electroporation (IRE) monitoring. Prospects and challenges for the clinical implementation of these techniques will be discussed. The successful development of these technologies will expand the current clinical paradigm towards precision medicine.
Verification of interaural cues using OpenSoundNavigator
Authors: Tsai Hannah , Diedesch Anna C.
Published: April 2023

Advancements in hearing aid technology have led to increasingly complex digital signal processing features. Processing strategies in Oticon Opn hearing aids have features including complex noise reduction and directional microphone technology that allows for amplification of speech located behind the listener. These features are meant to assist listeners in complex acoustic scenes, but it is currently unknown whether there are unintentional effects on the spatial location of auditory objects in the environment. Additionally, do open-fit versus occluding earmolds interact with the complex digital signal processing. This study examined effects of interaural cues for Oticon Opn hearing aids. Devices were placed on a Bruel & Kjaer Head and Torso Simulator (HATS) in an anechoic chamber. Spondees were played from 11 speakers (±75°) separated by 15° azimuth in quiet and in the presence of a speech-shaped noise. Two-channel recordings were analyzed using binaural models to evaluate frequency specific interaural cues for each speaker location. Hearing aids were coupled to HATS using open-fit and occluded domes and compared to unaided recordings. All features available in the OpnSoundNavigator fitting software were systematically evaluated. Enhancements, reductions, and distortions of interaural cues were found across conditions in comparison to unaided recordings.
The effects of aging on the across-frequency processing of interaural time differences
Authors: Bilokon Anhelina , Goupell Matthew J.
Published: April 2023

Aging and hearing loss cause temporal processing deficits, including poorer interaural-time-difference (ITD) processing, for simple stimuli like tones. However, there is little understanding of how aging and hearing lossaffect across-frequency ITD processing. Binaural models suggest that lateralization depends on the alignment of peaks of the interaural cross-correlation function across frequencies (“straightness”) and considerable weighting around 700 Hz (“dominant region”). We hypothesized that aging and hearing loss would reduce across-frequency ITD processing and/or shift the dominant region to lower frequencies. Sixteen younger normal-hearing (YNH, <45 yrs), ten older normal-hearing (ONH, >65 yrs), and ten older hearing-impaired (OHI) listeners performed an intracranial lateralization task. They were presented complex tones and narrowband noises with fixed upper-frequency boundaries, varying bandwidths, and ITDs. For complex tones, the range of lateralization was smaller for older compared to younger listeners, but there were no effects of hearing loss. Some conditions showed less efficient across-frequency ITD processing with age, and others showed the dominant region shifted to lower frequencies. For narrowband noises, there were no effects of age or hearing loss, suggesting that envelope ITDs can affect lateralization in this task. These results suggest that accounting for aging in across-frequency binaural processing models is important.
Event-related potential responses to differences in vibrotactile frequency: Evidence for continuous encoding of tactile information during early perception
Authors: Henderson M. Ryan , Toscano Joseph C.
Published: April 2023

Perception of vibrotactile frequency is driven by activation of different types of mechanoreceptors embedded in the skin, which respond to vibrations in a frequency range of approximately 0.4 to 500 Hz. While previous behavioral work has measured participants’ sensitivity to differences in vibration frequency, it is unclear how this information is encoded in neural representations during perception. This issue was addressed in an event-related potential (ERP) experiment investigating responses to vibrotactile stimuli. EEG data were recorded while participants rested their hand on a tactile transducer. On each trial, the transducer delivered a sinusoidal vibration with a duration of 1000 ms. Frequency of vibration ranged from 30 to 70 Hz in 10 Hz steps. Results revealed that frequency is encoded in early somatosensory ERP responses recorded at Cz. Specifically, the amplitude of a negative-going ERP component, centered at approximately 50 ms post-stimulus onset, increased as stimulus frequency increased from 40 to 70 Hz. These results demonstrate that vibrotactile frequency is encoded continuously during perception and that these responses can be measured using scalp-recorded EEG.
Investigating the parameters affecting spectro-temporal integration in pitch
Authors: Kooistra J. C. , Mehta Anahita H.
Published: April 2023

Previous research has shown that a virtual pitch percept of the fundamental frequency (F0) can be extracted from a sequence of non-overlapping, harmonically related tones in the presence of background noise. We have established that the F0 percept is strongest for low numbered harmonics and absent when only high-numbered harmonics (>10) are presented as well as when the tones are inharmonically related. The present series of experiments explores the effect of dichotic presentation, notched noise, and varying degrees of inharmonicity on this virtual pitch percept. F0 difference limens (F0DLs) for synchronous and sequentially presented components in noise were measured in normal-hearing participants. For the dichotic conditions, each ear received a random subset of components to investigate if this percept was dependent on peripheral interactions. The inharmonic conditions varied the extent of spectral jitter on each of the components (by 10%, 20%, and 30%) to understand if F0DLs worsened with increasing amounts of jitter. Finally, the notched noise conditions investigated whether background noise within the harmonic frequencies was essential for the F0 percept. Preliminary results indicate that the virtual pitch can be perceived dichotically and the characteristics of the background noise and harmonic relations play key roles in this illusory percept.
Modeling the nonlinear mechanics and dynamics of Cochlear Outer Hair Cell Stereocilia
Authors: Goyal Varun , Grosh Karl
Published: April 2023

Sound waves vibrating the eardrum excite the ossicles in the middle ear ultimately driving waves in the cochlea. Cochlear vibrations are processed by inner hair cells and outer hair cells (OHCs). Our focus is on the OHCs that nonlinearly amplify the sound converting a time-varying motion of its apically adorned hair bundle (HB) to an alternating current. The OHC HB consists of roughly three rows of stereocilia arranged according to their heights. Understanding how the bundle stiffness, sensitivity, and transduction current depend on the physiology and anatomy of the stereocilia is crucial and open question. Therefore, we are developing a three-row model of an isolated HB to quantify each row’s contribution to the passive and active mechanics of the HB. The derived equations of motion include the nonlinear kinematics, viscoelastic HB mechanics, and the nonlinear response of the mechano-electric transducer channels coupled to an adaptation mechanism. We also linearize the model to conduct stability analysis and determine the dependence of the responses on the rate constants. Our preliminary results show a higher current influx through the middle row than the shortest row and a more significant stiffness contribution from the middle-to-tallest row pair compared to the shortest-to-middle row pair connection.
Dissipation-induced acoustic nonreciprocity
Authors: Krokhin Arkadii
Published: April 2023

Linear acoustic transmission through a stationary elastic medium possesses Rayleigh reciprocal symmetry with respect to pressure produced by a source at point A(B) and measured at point B(A), pA(rB) = pB(rA). In ideal (inviscid) fluids, pressure plays the role of the scalar potential for velocity, v∼∇p. The Rayleigh reciprocity theorem is formulated for velocity potentials but not for their gradients. Any function of the absolute value of velocity, v(r), lacks reciprocal symmetry. In particular, acoustic intencity I = pv is not symmetric, IA(rB) ≠ IB(rA). Dynamics of ideal fluid is time-reversible, and lack of reciprocal symmetry is attributed to asymmetry in scattering. However, in a viscous environment dissipation breaks T symmetry making fluid dynamics irreversible. We report that acoustic transmission is not only irreversible but also becomes nonreciprocal due to different amount of dissipated energy for forward and backward propagation, provided that mirror symmetry (P symmetry) is broken. Since dissipation occurs within a narrow viscous layer at solid–fluid interface, the amount of nonreciprocity in transmission strongly depends on the quality of the surface of scatterers. Experiments performed with scatterers of different surface quality show how surface roughness affects the level of nonreciprocity. In a series of experiments with asymmetric phononic crystal, Tesla valve, and acoustic cavity, we demonstrate dissipation-induced nonreciprocity in transmission. [This work is supported by the NSF under EFRI Grant No. 1741677.]
Controlling elastic wave propagation in plates using magic squares
Authors: Vongsiri Marupong , Carrillo-Munoz Maria , Sharma Bhisham
Published: April 2023

A magic square is defined as a square array of distinct positive numbers arranged such that the sum along the horizontal, vertical, and main diagonal directions are the same, which is called a magic number. Previously, we leveraged the magic square concept to create a new class of phononic structures whose dispersion behavior can be tuned without altering their global mass and stiffness. In this study, we study the dispersion behavior of a thin plate with non-structural mass arranged in a magic square pattern. The plate unit cell is partitioned into nine portions and individual point masses are embedded at the center of each portion. Our results show that the magic square mass-embedded plate provides a low-frequency out-of-plane bandgap whose widths can be controlled while maintaining the global mass of the plate structure. Additionally, we investigate a magic plate concept by applying different densities at each portion associated with the magic square patterns. Our preliminary results show that the magic density distribution results in the emergence of polarized bandgaps and provides a possibility of altering the plate modal frequency without altering the mode shape or the global mass.
Unit cell of three nonlinear layers for the design of tunable nonlinear metamaterials
Authors: Ghodake Pravinkumar R.
Published: April 2023

Tang et al. (2012) and Kube (2017–2018) discussed the harmonic scattering of elastic waves from nonlinear inclusions through a theoretical perspective modeling early-stage damages as quadratic and cubic nonlinear elastic material models. Achenbach and Wang (2017–2018) studied the harmonic scattering of a wave from a single nonlinear layer embedded in a linear elastic material using the reciprocity theorem in elastodynamics and the concept of compensatory waves. They demonstrated sensitivity of the back and forward scattered waves towards the dimension and the intensity. Based on this understanding, a new unit cell is proposed in this study that can act as a tunable nonlinear metamaterial, where we can tune the amplitudes of the back and forward-scattered nonlinear waves. The unit cell contains three nonlinear layers of equal widths; the intensity of the central layer, along with the total width of the unit cell, is varied to tune the harmonic responses of scattered waves. Computational studies are carried out to demonstrate the presence and absence of harmonically backscattered waves from a unit cell. In some case studies, parameters are tuned so that the amplitudes of 2nd harmonics (2f) of forward, backscattered waves and waves recorded at the interfaces of the three nonlinear layers.
Comparing intelligibility and recognition memory of human and text-to-speech voices
Authors: Aoki Nicholas , Zellou Georgia
Published: April 2023

Clear speech can be more intelligible and better remembered than casual speech. Intelligibility and memory are assumed to be related—under the effortfulness hypothesis, the intelligibility-enhancing properties of clear speech (e.g., slower speech rate) facilitate processing, which frees up working memory resources and confers a memory advantage. However, prior work has only investigated naturally produced clear speech. How does clear speech influence memory for computer voices? The current study examines intelligibility and recognition memory of clear and casual speech for a text-to-speech (TTS) voice and a human voice, and compares older and younger adult listeners. In a speech-perception-in-noise task, clear speech was more intelligible than casual speech for both voices, the human was more intelligible than the TTS voice, and the younger adults performed better than the older adults. In an old-new recognition task, memory was better for the human voice relative to the TTS voice, consistent with the intelligibility results and the effortfulness hypothesis. However, inconsistent with the effortfulness hypothesis, there was no clear speech memory benefit, and the older adults performed better than the younger adults. The current findings are relevant for our understanding of human-computer interaction and theories about the relationship between speaking style and memory.
Acoustic characteristics of clear speech and noise-adapted speech in preschoolers
Authors: Yi Hoyoung , DiCristofaro Delaney
Published: April 2023

It is well-known that adults can change their speaking styles to make them more intelligible for their listeners. However, we do not know how young children can achieve the ability to alter their speech. The study investigated if preschoolers can modify their speech responding to challenging communicative situations. Children performed “spot the difference” tasks (Baker and Hazan, 2011) with a communication partner to elicit conversational speech (CO), noise-adapted speech (NAS), and listener-oriented clear speech (CL) production. We examined the acoustic features of the three speaking styles in 28 preschoolers. Suprasegmental features of CO, NAS, and CL were analyzed, including F0 (Hz), F0 range (Hz), energy in the 1–3kHz range(dB), and speech rate(syllables per second). Results showed conversation-to-NAS modifications for all four acoustic measures in all age groups. For conversation-to-CL modifications, all age groups decreased their speaking rate. The 5-year-olds increased their energy and pitch for CL. The 4-year-olds also increased the pitch for CL. The 3-year-olds did not change pitch and decreased energy for CL, which displays the opposite tendencies of adults. Preschoolers appear to be aware on some level of the challenging nature of communicative environments. They undergo ongoing development of speech modification for their listeners.
Acoustic correlates of perceived anger in the Ferguson clear speech database
Authors: Young Elizabeth D. , Morgan Shae D. , Ferguson Sarah H.
Published: April 2023

Previous work has shown that clear speech is perceived as sounding angry significantly more often than conversational speech (Morgan and Ferguson, 2017; Young, 2021). The current study examined possible acoustic correlates of perceived anger in clear speech. A principal component analysis was completed to guide selection of acoustic variables for analysis. The remaining six acoustic measures, fundamental frequency median, fundamental frequency variability, relative mid-frequency energy from 1000 to 3150 Hz, speaking rate, and degree of amplitude modulation at 2 Hz and 16Hz envelopes, were analyzed using mixed effects regression. Results indicated that after controlling for speaking style, fundamental frequency approached significance but did not significantly predict perceived anger. However, speaking rate significantly predicted perceived anger after controlling for speaking style, with slower rates leading to an increase in perceived anger. Further, there was a significant interaction between speaking rate and speaking style, where slower speech was only perceived as angry in the clear speech style. Finally, a decrease in the degree of low-frequency amplitude modulation (i.e., equal emphasis on both content and function words) led to an increase in perceived anger after controlling for speaking style. The results have implications for counseling individuals in the use of clear speech.
Speech intelligibility and listening effort: A dual-task paradigm for accented speech perception
Authors: Mallard Mel , Van Engen Kristin J.
Published: April 2023

Unfamiliar accents can make speech communication difficult, both by reducing speech intelligibility and by increasing the effort listeners must put forth to understand speech. In general, intelligibility refers to the proportion of words that a listener can correctly identify (100%, 50%, etc.), while listening effort refers to the cognitive resources that must be devoted to a difficult listening task. Generally, lower intelligibility is related to higher effort. However, it is now apparent that these two constructs, while related, are independent: for example, two 100% intelligible speakers may elicit different amounts of effort. To better characterize the relationship between intelligibility and effort, this study presents speakers of four intelligibility levels (one L1 English speaker, and three Mandarin-accented English speakers) within a dual-task paradigm (featuring a vibrotactile secondary task) to measure listening effort. We hypothesize an inverse relationship between intelligibility and effort, but the shape and slope of this relationship are of primary interest. These results will begin to illuminate the relationship between intelligibility and effort across a more continuous range of accent intelligibility. Data collection is ongoing. Results for the Mandarin Chinese accent will be presented. Preliminary results for the study’s second iteration (using a Korean accent) will also be presented.
Effect of a portable sound-booth on teachers’ voice acoustic parameters
Authors: Cantor-Cutiva Lady Catherine , Hunter Eric J.
Published: April 2023

Background: College professors expose themselves to different vocal demands during teaching. During the COVID-19 pandemic, college professors were exposed to extra working loads associated with working from home, with less-than-optimal acoustic conditions. This is the reason why it was needed to think of easy-to-implement and low-cost solutions for online teaching from home. Objective: To evaluate the effect of an insulating cabin prototype on the voice acoustic parameters of college professors during homeworking. Methodology: Longitudinal study with the participation of 32 (thirty-two) full-time college professors. Participants were asked to fill out a questionnaire before reading a paragraph of around 30 seconds of duration with and without the portable sound booth. A type I sound level meter was used to measure the background noise in professors' teaching environments with and without the cabin prototype. Results: Voice acoustic parameters changed when voice production was performed with the portable sound booth. Therefore, this low-cost solution is a good alternative to prevent vocal effort and vocal fatigue among teachers.
Comparing the effects of target and masker voice familiarity on children’s speech-in-speech recognition
Authors: Flaherty Mary M.
Published: April 2023

Familiarity with a target voice has been shown to aid spoken word recognition for both children and adults. Familiarity effects of a target voice are not well understood, and even less is known about the impacts of masker voice familiarity. The present study investigated long-term target and masker voice familiarity effects on children’s speech-in-speech recognition by using the child’s own mother’s voice as stimuli. Open-set sentence recognition thresholds (SRTs) were measured adaptively in a two-talker speech masker. Twenty children were tested in three conditions, hearing their mother’s voice and two unfamiliar female voices: (1) Familiar Target/Unfamiliar Masker; (2) Familiar Masker/Unfamiliar Target; and (3) Unfamiliar Target/Unfamiliar Masker. Condition 1 measured effects of target familiarity; Condition 2 examined effects of masker familiarity; Condition 3 served as baseline. Results showed SRTs were significantly better when target speech was spoken by a familiar talker (the mother). When background speech was spoken by the familiar talker, performance was worse relative to an unfamiliar masker. This suggests that children do benefit from long-term voice familiarity with the target but not the masker speech. Thus, voice familiarity may impact children’s ability to attend to the target speech but does not always improve segregation.
Voice acoustics and effort of three different communication scenarios presented in an anechoic baseline
Authors: Berardi Mark , Hunter Eric J.
Published: April 2023

While vocal pathology can elevate vocal effort, communication situations also have an effect. Previous work on vocal effort and communication situations have relied on listener ratings of effort rather than talker-centric vocal effort. Towards that end, in this study, talker-centric vocal effort was related to different communication demands. Additionally, vocal performance was measured to investigate potential relationships between effort, production, and communication demand. In an anechoic chamber, participants described to an interlocutor various maps. The communication demands were communication distance (1, 2, 4 m), loudness goal (54, 60, 66 dB), and background noise (53, 62, 71 dBA). Talkers rated their vocal effort after each task with a Borg CR100 scale and were recorded with a calibrated head-worn microphone. There were significant increases in ratings of vocal effort, fundamental frequency, intensity, and cepstral-peak prominence (CPP) from the control condition to the extremes of the distance and loudness goal vocal demands which are consistent with previously observed Lombard responses. This study shows that communication demands that exceed typical conditions (such as talking at 4 m) result in increases in vocal effort and a Lombard-like response. Therefore, considerations to potential communication barriers are important for the reduction of vocal effort.
Floor impact noise—The history and future of ASTM E3133
Authors: Lilly Jerry G.
Published: April 2023

The fundamental purpose of ASTM E3133 is to provide a test method for rating the relative noisiness of floor impacts (e.g., footfalls, dropped objects, and rolling carts) on a variety of finished flooring products. Unlike previous impact noise standards which only address the impact noise radiated to other nearby spaces, the focus of this test method is to evaluate the noise radiating into the source room where the floor impacts occur. Health care facilities and performing arts venues are an obvious application, but data of this type may also be important in other facility types including schools, churches, and courtrooms. Major flooring product manufacturers have been asking for this type of standardized test data for many years. This presentation will highlight the work conducted over the last decade in the development of this standard, culminating in the adoption of the standard in 2018, its recent withdrawal, and plans for a future revision.
Acoustic properties of chimpanzee pant-hoots reflect male mate quality
Authors: Desai Nisarg , Fedurek Pawel , Slocombe Katie , Arcadi Adam Clark , O'Bryan Lisa , Uhlenbroek Charlotte , Wilson Michael
Published: April 2023

Sexual selection theory predicts that acoustic structure may provide cues of individual traits correlated with mate quality. Chimpanzee pant-hoots are complex, conspicuous calls that may be products of sexual selection. Insofar as pant-hoots are difficult to produce, requiring individuals to approach their physiological limits of sound production, they may serve as honest signals of physical condition. The highest pitch elements in pant-hoots appear the most difficult elements to produce, as they sometimes exhibit distortions in acoustic structure known as non-linear phenomena (NLP). Producing high pitch vocalizations with fewer NLPs may, thus, signal superior physical condition. We examined whether the proportion of NLPs, the pitch, and noise in these elements of the pant-hoots contain cues of mate quality including age, rank, and a measure of health (infection with the simian immunodeficiency virus, SIVcpz), and if they predict male mating success. Consistent with predictions from sexual selection, we found that (i) the proportion of NLPs was associated with age in a non-linear fashion—specifically, subadult and old males exhibited higher proportions of NLPs compared to males in their prime mating age; (ii) a lower proportion of NLPs predicted higher mating success; and (iii) SIVcpz positive individuals exhibited more noise in their pant-hoots.
Regularities in spectral entropy variations within humpback whale song sessions
Authors: Mercado Eduardo , Ashour Mariam , Krsmanovic Gala , Hyland Bruno Julia
Published: April 2023

Consecutive songs produced by humpback whales recorded off the coast of Hawaii show recurrent patterns of acoustic variation. Analyses of spectral entropy, a measure of the uniformity of energy distribution in the frequency domain, revealed that spectral entropy cycles in predictable patterns within song sessions. At time scales spanning tens of minutes, variations in spectral entropy appear to track changes in received intensity levels, which are correlated with song duration and may reflect the diving behavior of singers. Intra-individual variations in spectral entropy suggest that singing humpback whales may also vocally control entropic features of songs, both by gradually modulating the acoustic characteristics of units and by varying the amount of time they spend producing specific patterns of units. Preliminary analyses suggest that variations in spectral entropy within song cycles are indicative of the amount of time and energy singers spend producing constant-frequency (CF) elements versus more frequency-modulated/broadband elements. CF elements of units are generally more difficult to spatially localize, but easier to detect over long distances, suggesting that singing humpback whales may be varying the production of consecutive songs in ways that affect auditory spatial processing.
Using passive acoustic monitoring to characterize vocal behaviors of sperm whales (Physeter macrocephalus)
Authors: Rankin Cara L. , Joseph John , Margolina Tetyana
Published: April 2023

Sperm whales (Physeter macrocephalus) have been observed but not well studied in the Monterey Bay National Marine Sanctuary (MBNMS). Vessels transiting through MBNMS may pose a threat to sperm whales and modify their behavior. Knowledge of their activity in relation to vessel presence in MBNMS is largely unknown. In this study, passive acoustic monitoring (PAM) data collected at the Sur Ridge, in close proximity to shipping lanes, are used to characterize vocal and foraging behaviors of sperm whales in relation to vessel transits through MBNMS. PAMGuard automated detectors are used to detect sperm whale clicks and measure inter-pulse intervals with feature-based post-processing to reduce false positives. Probability density functions are used to determine distribution of sperm whale size, sex, and presence in relation to vessel transits. Foraging clicks were positively detected in sequences of bouts from June-August, 2020. Sperm whales observed were adult males. Container ship signatures were observed to cover the same frequency bandwidth as sperm whales with a higher amplitude. This study provides insight on the importance of MBNMS to sperm whales and informs policy makers on potential effects that shipping may have on sperm whale behavior, while providing a novel method to analyze PAM data.
Coronavirus disease 2019 patients prognostic stratification based on low complex lung ultrasound video compression
Authors: Khan Umair , Afrakhteh Sajjad , Mento Federico , Smargiassi Andrea , Inchingolo Riccardo , Tursi Francesco , Narvena Veronica , Perrone Tiziano , Iacca Giovanni , Demi Libertario
Published: April 2023

In the last years, efforts have been made towards automating semi-quantitative analysis of lung ultrasound (LUS) data. To this end, several methods have been proposed with a focus on frame-level classification. However, no extensive work has been done to evaluate LUS data directly at the video level. This study proposes an effective video compression and classification technique for assessing LUS data. This technique is based on maximum, mean, and minimum intensity projection (with respect to the temporal dimension) of LUS video data. This compression allows preserving hyper- and hypo-echoic regions and results in compressing a LUS video down to three frames, which are then classified using a convolutional neural network (CNN). Results show that this compression not only preserves visual artifacts appearance in the reduced data, but also achieves a promising agreement of 81.61% at the prognostic level. Conclusively, the suggested method reduces the amount of frames needed to assess LUS video down to 3. Note that on average a LUS videos consists of a few hundreds frames. At the same time, state-of-the-art performance at video and prognostic levels are achieved, while significantly reducing the computational cost.
Graduate student mentoring by Lawrence A. Crium
Authors: Crum Lawrence A.
Published: April 2023

For a period in excess of 55 years, I have had the opportunity and privilege to serve as an advisor to over 50 students at various levels of their academic instruction and development, particularly at the graduate and postgraduate level. Many of my students have achieved noted success in their careers and have served as Society Presidents, as Deans of Engineering schools, and Directors of Government Labs. Having no established approach to student mentorship, this success has been one of selecting good students with a potential for success in any field and providing them with an opportunity to develop their own careers. Indeed, my style has been one of “benign neglect,” if any. Nevertheless, I will attempt in this lecture to describe what I see is an approach that has resulted in successful career development for my students.
Jack of all trades: Challenges and opportunities for mentoring in interdisciplinary research
Authors: Stride Eleanor P.
Published: April 2023

Biomedical acoustics spans a particularly broad range of disciplines from neuroscience to quantum physics and everything in between. While this diversity is exciting and constantly stimulating, it can pose considerable challenges for students and mentors in finding the appropriate balance between breadth and depth. The aim of this talk is to share the author’s experience of designing graduate and undergraduate courses in biomedical acoustics and particularly of supervision and team building for graduate and post-doctoral researchers from different disciplines. Key topics will include the importance of co-supervision, promoting understanding and implementation of the scientific method; encouraging curiosity driven experiments; vital lessons from science communication; and finally the surprising insights provided by training to teach dance.
Lessons learned from mentoring and being mentored in a large environment
Authors: O'Reilly Meaghan
Published: April 2023

The Focused Ultrasound Lab at Sunnybrook Research Institute has over 60 regular members and trains an additional 30 + summer students each summer. Drawing on the speaker’s experience, as well as trainee data, this talk will focus on approaches to effective mentoring in a large environment. The role of mentor teams within biomedical acoustics and in other related fields will be discussed.
Mentoring from the other side of the fence: Student perspectives on good advising
Authors: Anderson Megan S.
Published: April 2023

As a fourth-year graduate student and ASA Student Council representative, I have had access to the opinions of students and gained insight on what they expect from their mentors and advisors. In this talk, I hope to demystify the student perspective by discussing the themes that have emerged from both Blackstock Mentor Award applications and a mentoring survey sent to Biomedical Acoustics students. One question drives the analysis: What kind of mentor/mentee relationship leads to the most successful outcomes and how is that success measured by students?
Correlation of electric field and acoustic output on a prismatic biaxial transducer: A finite element study
Authors: Salazar Cabral Javier D. , Chong-Quero J. E. , Delgado Sagid , Pichardo Samuel
Published: April 2023

In single multiaxial transducers, the ultrasound beam can be steered by shifting the phases of the signals of two or more orthogonal electric fields applied to the piezoelectric. These capabilities can improve focusing on therapy applications such as transcranial focused ultrasound. A biaxial piezoelectric transducer (DL47, DelPiezo, FL) was modelled using the finite element software COMSOL Multiphysics®. The upper face was in contact with a volume of water, while the rest were free. The steering angle was controlled by varying the difference between the electrodes’ phases at the crystal’s resonant frequency. To reduce bias, the acoustic particle velocity was recorded at various lengths above the upper transducer's face while the average electric field was calculated for different areas on the surface. Linear regression fits of the steering angle with respect to the average electric field and particle velocity were calculated. A correlation can be observed between the average electric field at the center of the piezoelectric and the steering angle. Furthermore, by reducing the recorded length of the particle velocity by 30%–40% there is a high correlation with the steering angle. A model can be derived using these correlations in which the ultrasound beam direction can be known by obtaining the electric field at the center of the crystal. [The authors want to acknowledge the support of the Government of Canada by the scholarship provided by Global Affairs Canada through the Emerging Leaders in the Americas Program.]
Numerical and Theoretical Investigations on Twin Standing-wave Thermoacoustic Prime Movers
Authors: Guan Lixian , Zhao Dan
Published: April 2023

In this work, we perform computational fluid dynamics investigations topredict the performance of the twin thermoacoustics engine (TAE) undervarious working gas/medium and at different charge pressures. The numerical model is validated by comparing with those of DeltaEC (Design Environment for Low-amplitude ThermoAcoustic Energy Conversion) predictions and previous experimental results. Additionally, the effects of (1) the geometry shape of the twin TAE and (2) different types of working gases on its performance are examined. The results indicate that the working gas/medium and charge pressure in the engine are critical to the twin thermoacoustic engine. Although the acoustic pressure amplitude is higher with air or nitrogen as the working gas, the acoustic oscillation frequency is higher with helium or argon and the value of the acoustic growth rate is larger, i.e., the limit cycle is observed growing faster in the twin TAE. Furthermore, the pressure-ratio is increased in the tapered resonator, because its velocity amplitude is decreased. It means the tapered resonator is the best choice for the twin TAE. The acoustic characteristics predicted are much closer to the experimental results than those of DeltaEC estimations, which provides a design tool for designing and predicting performances of twin TAEs.