bluuebunny/crossref_metadata_2025 huggingface dataset:
Boundary-induced prosodic strengthening and its function in interactive and read speech
Authors: Shin Seulgi , Tremblay Annie
Published: November 2021

This study investigates the functions of boundary-induced prosodic strengthening relative to speech style, focusing on English plosives and nasals in Intonational-Phrase(IP)-initial and IP-medial positions in interactive and read speech. Two accounts seek to explain the function of prosodic strengthening: syntagmatic contrast enhancement (SCE: enhancement of the contrast between neighboring consonants and vowels) (e.g., Cho & Keating, 2001) and paradigmatic contrast enhancement (PCE: enhancement of phonological contrasts) (e.g., Georgeton & Fougeron, 2014). For interactive speech, pairs of participants produced words while exchanging information about scenes; for read speech, each participant individually produced words in written sentences. For plosives, Voice-Onset-Time measurements showed SCE in read speech, with plosives being more consonant-like (less voiced) IP-initially than IP-medially, but PCE in interactive speech, with voiced and voiceless plosives being more distinct from each other and from other places of articulation IP-initially than IP-medially; spectral measures showed PCE in both interactive and read speech. These results suggest that speakers make plosives phonologically more distinct from one another in interactive speech to help listeners identify them better. Nasals were more consonant-like (less nasality) IP-initially than IP-medially in both interactive and read speech, showing SCE, attributable to nasals being phonetically and phonologically distinct from non-nasal consonants.
Evidence for F0 preplanning with delayed stimuli
Authors: Kim Seung-Eun , Tilsen Sam
Published: November 2021

A sentence production experiment was conducted to investigate F0 preplanning, specifically examining whether speakers plan pitch targets according to utterance length and whether preplanning limits dynamic control of pitch range. The experiment used a novel elicitation method in which visual stimuli that cue part of the utterance are delayed so that participants initiate the utterance without knowledge of its length. Participants read sentences in which the subject noun phrase was composed of one, two, or three conjoined noun phrases with controlled lexical and phonological content (e.g. Eight red weasels and nine green rhinos and eight blue llamas live in the zoo). On half of the trials with two and three noun phrases, the presentation of the visual stimuli that cued non-initial phrases (e.g., nine green rhinos and eight blue llamas) was delayed until after detection of utterance initiation. The effects of length and delay on F0 measures were analyzed. The results showed the length effect; the utterance-initial F0 peak was highest when three phrases were presented initially and lowest when one phrase was presented initially. Moreover, the utterance-initial peak in delayed stimuli was similar to that of the single phrase stimuli. In non-initial phrases, the pitch range of the delayed stimuli was constrained such that the F0 peak of the stimuli without delay was higher than those with delay. The findings suggest that speakers plan F0 targets and range before production, and such planning restricts subsequent control of F0.
Intonational phonology of Farasani Arabic: intonation ignores stress unless a word is focused
Authors: Abbas Abeer A. , Jun Sun-Ah
Published: November 2021

This study proposes an Autosegmental-metrical model of intonational phonology of Farasani Arabic, an under-documented dialect of Arabic spoken in the Farasan Islands, Saudi Arabia. Tonal patterns of utterances, produced in neutral and narrow focus contexts, were examined by varying the length of a word and a phrase, the location of stress, syntactic structures, and sentence types. Results suggest that Farasani Arabic has three prosodic units higher than a word: Intonational Phrase > Intermediate Phrase > Accentual Phrase (AP). An AP is defined by a rising tonal pattern, [L Ha], without including a pitch accent, even though the language has stress. This is unique among Arabic dialects and also typologically unusual. So far, only a few languages (e.g., Kuot, Uyghur) have been claimed to be an exception to the association between stress and intonational pitch accent. A further unique feature of Farasani Arabic is that a pitch accent (H*) does occur on the stressed syllable of a word when the word is emphasized (in this case, the AP final tone is Low, i.e., [L H* La]). In other words, stress is partially involved in the intonation system of Farasani Arabic, further challenging the current models of intonational phonology and prosodic typology.
Design of a flagship studio suite for a major recording arts educational program
Authors: Paek Hyun , Siebein Gary W. , Miller Jennifer , Vetterick Matthew , Roa Marylin
Published: November 2021

The architectural acoustic design of a studio, isolation booth and control room as well as an intimate performance hall for amplified music was undertaken for a major recording arts educational program. The university which already has many recording studios, considered this facility as their “Audio Temple” or the showpiece of the entire campus. Acoustical design criteria for reverberation time, low frequency sound control, room response, diffuseness, background noise and sound isolation were established in conjunction with the faculty who will use the spaces. There are classroom spaces above the studio suite and mechanical equipment located near-by, so sound isolation design was an important part of the design effort. A three-layer sound isolation system was used for each of the rooms. The faculty had specific requirements for the interior acoustical qualities of the rooms. The paper presents comparisons of the rooms as designed with the criteria for acoustical quality described by the users for reverberation, low frequency sound, room response, diffuseness and background noise. Efforts were maintained during design and construction to preserve these qualities through the realities of the value engineering and construction process.
Converting an empty office to a podcast studio
Authors: Savitala Indi
Published: November 2021

Companies of various types are converting empty offices to podcast studios. The existing office space presents many acoustic challenges: (1) single-glazed office front, (2) proximity to noise producing adjacency, (3) limited available surface area for room finish treatments, and the list goes on. This presentation analyzes an existing office space that was converted to a podcast studio and presents criteria and recommendations that were used to optimize the space for recording.
Transformation of a warehouse into a professional production studio
Authors: Paek Hyun , Siebein Gary W. , Miller Jennifer , Roa Marylin , Vetterick Matthew
Published: November 2021

A major film production studio was slated for demolition due to the expansion of a theme park. Audio tracks for many popular films and animated productions were designed, recorded and mixed in the facility. Space for the new studio was included in a large office renovation project that was occurring in several large existing warehouse/office buildings. The acoustical challenges of providing sound isolation between and among adjacent recording, control and editing spaces as well as between the studios and the exterior which included building box-in-box-in-box isolation systems within the existing warehouse posed an interesting challenge. With the unforgiving structural system of the existing warehouse building, thinking both outside and inside of the box was necessary. Fitting the low velocity ductwork in the relatively low ceiling height of the existing structure was not easily accomplished. Each of the existing limitations of the warehouse building was overcome by closely working with the Design Team and the Contractor. Acoustical shaping and finish materials were designed and selected to meet the criteria of the users for reverberation, room response, low frequency sound control, diffuseness and background noise. The users were pleased to work in a studio that allowed the artists and the engineers to work throughout the day into the night and through thunderstorms. The studio has been very well-received by the users, since the resulting sound tracks translated very well when played back in a variety of venues.
A study of a renovated broadcast control room with a concave enclosure
Authors: Eligator Ronald , van der Harten Arthur W.
Published: November 2021

Broadcast control rooms are monitoring stations which can have many operators. One such room with ellipsoidal plan shaping was recently renovated. The original room had sufficient absorptive wall treatment, such that any focusing effects were less obvious, and the occupants could perform their work in relative comfort. The renovated space included much more computer screen equipment—so much so that the original treatment was covered, and the concave surface shaping was duplicated in hard surfaces. The resulting space was distracting for the occupants, due to whispering gallery effects, and at times could become excessively loud. In this talk, we discuss our process for measuring anomalous effects in the space using room impulse response measurement techniques, as well as our computer modelling approach, which helps us identify the surfaces implicated in the measured anomalies. We will also discuss our proposed solutions, and the challenges associated with each.
The need to standardize soundscape analysis metrics—A case study: Comparing temporal and spectral kurtoses of underwater sounds
Authors: Martin S. B. , Alavizadeh Zahra
Published: November 2021

To evolve our ability to compare soundscapes across time, location and research groups, a standard suite of metrics is essential. Significant progress towards establishing standard approaches for quantifying the amplitude of the soundscape has been made in recent years, however advancing qualitative metrics has been challenging. Temporal kurtosis is often proposed as a soundscape metric that quantifies impulsiveness, and that filtering a sound for an animal’s audiogram could quantify the impulsiveness for animals with different hearing capabilities. This frequency-weighted kurtosis could be computed by filtering in the time domain, or perhaps by computing the spectral kurtosis over the hearing range. Comparing the two approaches provides a case study for the importance of standardizing analysis methods. Here the temporal and spectral kurtosis of common underwater sounds are compared. The band-limited temporal and spectral kurtoses are correlated for sounds from vessels, natural sounds, and seismic airgun surveys. They are substantially different for impact and vibratory pile- driving and the spectral kurtoses depend heavily on the analysis parameters, a result that is similar to a previous study of the acoustic complexity index. It is concluded that for qualitative soundscape metrics, standardized analysis methods are essential.
Listening space reduction calculations
Authors: Hannay David E.
Published: November 2021

Listening space reduction analysis has been applied recently by several authors to evaluate the relative reduction of distance or space within which listeners can effectively detect and recognize important sound sources, due to increased acoustic masking caused by a known increase in masking noise. The approach balances the increased masking noise level by reducing source-listener distance so that propagation loss is commensurately reduced. Its recent applications have not considered all important parameters, including listener hearing sensitivity and directionality, listener cognitive signal processing gain, non-uniform acoustic propagation loss, and temporal and spatial distributions of masking noise variability. Here we derive the listening distance and space expressions from the sonar equation, accounting for the parameters above. Listening space reduction calculations are insensitive to some uncertain parameters, including source level and detection threshold (for non-human listeners) that are required for communication space calculations. The method is applicable to any sound type, including predator sounds, prey sounds, conspecific communications, and natural sounds. A modified version of the method is derived for echolocation sounds, and a corresponding echolocation space reduction factor is derived.
Large-scale assessment of masking potential by underwater ship noise the North Sea
Authors: Tougaard Jakob , Folegot Thomas , de Jong Christ , Griffiths Emily T. , von Benda-Beckmann Alexander M. , Merchant Nathan D. , Kinneging Niels A.
Published: November 2021

The JOMOPANS project created one year of soundscape maps of the North Sea, based on ship information from the Automatic Identification System (AIS) and a ship source model. This assessed the potential impact of ship noise on the marine ecosystem through the masking of communication and other relevant acoustic signals. Specifically, the excess noise was quantified, which express the deterioration of the signal-to-noise ratio caused by the ship noise and hence the reduction in maximum communication range. The dominance of ship noise over natural sources was quantified as the percentage of time where excess was 20 dB or higher. A decrease in signal-to-noise ratio of 20 dB compared to a reference condition (ambient plus weather) without ships indicates a substantial decrease in communication range, and hence a substantial risk of impact on the ecosystem. Maps of excess and dominance in different frequency bands showed the largest ship contribution in the lowest frequency bands and in the most trafficked areas, with less affected areas in shallow waters, including the Dogger Bank. These maps, in combination with distribution maps of sensitive species, form the basis for the joint assessment of environmental status of the North Sea by the surrounding countries.
Using Axial Base cabled array sensor data to study the prediction of second-order pressures from nonlinear surface wave interactions associated with microseisms
Authors: Korde Umesh A. , McBeth Michael S.
Published: November 2021

There are currently no published experimental measurements of second-order pressures in the water column from nonlinear surface wave interactions. Microseism researchers have focused on predicting and measuring microseisms directly without measuring second-order pressures in the water column. We considered several Ocean Observatory regional cabled arrays as sources for water column measurements to compare with analytical model second-order pressure predictions based on hindcast directional wave spectra. We selected the Axial Base cabled array for its location and suite of instruments including two hydrophones, 3D velocity sensor, and seismometer near the seafloor. Here we present results for predicted second-order pressures along with hydrophone measurements at the Axial Base site over different times of a year (2019–2020) to demonstrate a correlation. Validating a prediction model for second-order pressures based on directional surface wave spectra using the OOI cabled array sensor data could spur development of wave energy harvesting devices in the deep ocean and other applications.
Low-intensity pulsed ultrasound induces metabolic lipolysis of adipocytes
Authors: Kim Sangnam , Yoon Sangpil
Published: November 2021

We used low-intensity pulsed ultrasound (LIPUS) to uncover underlying lipolysis mechanism of 3T3-L1 adipocyte. Ultrasound pulses with the center frequency of 2 MHz were applied for 10 min/day to promote the lipolysis of white adipocyte. Lipolysis is the process of breaking down lipids and the metabolic pathway through which lipid triglycerides are hydrolyzed into a glycerol and three fatty acids. The proliferation of 3T3-L1 adipocytes was detected by cell viability XXT assay, RT-PCR and Western blot. The Triglyceride Assay quantitatively measures triglycerides levels in differentiated adipocytes. LIPUS reduced the triglycerol content significantly in adipocytes. The differences between transcriptional genes and metabolites were analyzed by transcript analysis and metabolomic profiling experiments. The results of RT-PCR, and Western blot after LIPUS showed the increased lipolysis. The expression of genes related to lipolysis-related factors, ATGLand HSL, was up-regulated. In addition, cellular RNA-sequencing (RNA-Seq) showed an increase in lipolysis and adaptive immune cells under ultrasound stimulation. The algorithm and additional analysis reveals a gene network that is predicted to be associated and potentially drive adipocyte lipolysis and heterogeneity. LIPUS can promote the lipolytic capacity of 3T3-L1 cells in the differentiated state. This study provides an important experimental and theoretical basis for the clinical application of LIPUS in promoting the lipolysis of 3T3-L1 adipocytes.
Characterization of nonlinear field of a dual-mode linear array for image-guided applications of pulsed high-intensity focused ultrasound
Authors: Khokhlova Vera A. , Yuldashev Petr V. , Williams Randall P. , Karzova Maria M. , Kaloev Azamat Z. , Nartov Fedor A. , Khokhlova Tatiana D.
Published: November 2021

Recent studies have shown that nonlinear pulsed high-intensity focused ultrasound (pHIFU) is capable of inducing cavitation, without the need for contrast agents, to enhance drug delivery in tissues with poor perfusion. Here, acoustic characterization of a dual-mode linear array designed for image-guided cavitation-enhanced drug delivery applications is performed. The array consists of 64 elements (1.07 MHz, 14.8 × 51.2 mm2, 0.8 mm pitch) and is controlled by an ultrasound system (V1 Verasonics) configured with an external power supply for pHIFU excitation. Acoustic holography measurement data were collected for varying focus position electronically steered in the transverse and axial directions and used for setting a boundary condition in the acoustic model. Nonlinear simulations of the array field are performed using the Westervelt equation at increasing power outputs of the array. Modelling results are validated by comparing with pressure waveforms measured in the focus using a fiber optic hydrophone. It is shown that the amplitude of the shock fronts formed at the focus increases for larger focusing angles of the field and is sufficient to maintain the therapeutic level of cavitation. Simulation results are in good agreement with the measurement data. [Work supported by NIH R01EB023910 and RSF 20-12-00145.]
Dependence of cavitation behavior induced by a pulsed high-intensity focused ultrasound array on focal waveform parameters and transducer F-number
Authors: Williams Randall P. , Karzova Maria M. , Yuldashev Petr V. , Khokhlova Vera A. , Cunitz Bryan W. , Morrison Kyle P. , Khokhlova Tatiana D.
Published: November 2021

Pulsed high-intensity focused ultrasound (pHIFU) is capable of inducing cavitation without the need for contrast agents, which can enhance drug transport in tissues with poor perfusion. We report on the experimental characterization of cavitation induced by a new dual-mode ultrasound arraydesigned for image-guided pHIFU therapies. The 64-element array (1.071 MHz, aperture of 14.8 × 51.2 mm2 and pitch of 0.8 mm) is driven by the Verasonics V1 ultrasound system, configured for pHIFU excitation. Acoustic properties of the beam in the focal region were characterized through hydrophone measurements in the linear and nonlinear operating regimes while steering the beam azimuthally and axially. A high-speed camera was used to observe the cavitation behaviors induced in tissue-mimicking gel phantoms near the focus of the beam for different pHIFU exposure parameters. As the focal pressure increases, a change in cavitation behavior occurs, from the appearance of single, stationary bubbles, to groups of proliferating bubbles. The pressure at which the transition from stationary to proliferating cavitation was observed corresponds to the onset of shocks in the focal region. Beams with larger F-numbers were shown to induce cavitation at lower pressures than beams with lower F-numbers. [Work supported by NIH R01EB023910 and RSF 20-12-00145.]
Demonstration of nonlinear interaction of crossed turbulent streaming jets
Authors: Cartron Jenna M. , Korman Murray S.
Published: November 2021

An experimental apparatus was built for demonstration purposes involving two mutually perpendicular crossed ultrasonic turbulent streaming jets in water. A 2D Particle Imaging Velocimeter (LaVision) measured the turbulent flow generated by their interaction. Experiments were performed in an open 10 cc acrylic water tank. The apparatus consisted of two Langevin ultrasonic transducers—both equipped with stepped horns with section diameters: 1/2, 1/4 and 1/8 in.2. A kit developed by Sonics and Materials included a 40-kHz oscillator driving a 20 W amplifier (impedance matched to the 40 kHz transducer CV245) and stepped horn (Part # 630-0594). Two such units were needed to generate the crossed ultrasonic turbulent streaming jets. In the viewing plane the axes of each streaming jet was—i cos30—j sin30, + i cos30—j sin30, respectively. The horn tips (1/8 inch) (slightly submerged in the water) also generated small cavitation bubbles. Lighthill’s theory of acoustic streaming (1978) for a single source will be discussed. Lighthill recognized the importance of “Stuart streaming,” Reichardt’s turbulent jet measurements, Schlicting’s turbulent jet theory (involving eddy viscosity) and Squire’s exact solution for a nonlinear laminar jet flow. Earlier, Lighthill predicted that a turbulent jet would generate aerodynamic sound.
Nonlinear scattering of crossed ultrasonic beams in the presence of a turbulent bubbly jet flow in water
Authors: Haas Katherine A. , Korman Murray S.
Published: November 2021

Experiments involve the nonlinear scattering of mutually perpendicular crossed ultrasonic beams of primary CW frequency components: f1 = 2.240 MHz, f2 = 2.293 MHz; interacting nonlinearly with turbulent bubbly shear flow generated by a circular water jet (nozzle exit diameter D = 1.6 mm and volume flow rate 32 cc/s). The jet axis is perpendicular to the crossed beam axes. The nozzle exit is downward (5 mm above the surface). The water pump’s suction port was at the bottom center of the 10 cm cubic acrylic water tank (wall thickness 4.8 mm). Identical 1.27 cm diameter quartz transducers (T1 and T2) were epoxied at the centers of adjacent vertical tank sidewalls generate the primary beams (in the i or j directions). Identical 4.5MHz receiving transducers (6.35 mm diam PZT-4) measure nonlinear scattering in the forward or backscattered directions. Receiver Rf located in the plane formed by the primary acoustic beam axes) detects in the i cos 45 + j sin 45 direction. Receiver Rb was located in the opposite direction. In the absence of turbulence virtually no radiated sum frequency component exists. Doppler shift, frequency broadening, skewness and kurtosis from the received sum frequency power spectrum were measured.
Ultrasound coherent plane-wave compound imaging: Image quality evaluation in phantoms and breast lesions
Authors: Hendriks Gijs , Weijers Gert , Chen Chuan , Hertel Madeleine , Lee Chi-Yin , Dueppenbecker Peter , Radicke Marcus , Milkowski Andy , Hansen Hendrik , de Korte Chris L.
Published: November 2021

Coherent plane-wave compound imaging (CPWCI) can achieve high temporal resolution (e.g., to prevent breathing artefacts in volumetric scanning). It has to be verified that CPWCI using a limited number of steering angles (na) can achieve at least similar image quality as conventional focused imaging (CFI). The aim is to compare image quality between CPWCI and CFI in phantom and in breast lesions. In CPWCI, plane-wave channel data were recorded (na = 15, ±11 deg) by a Sequoia Ultrasound system (10L4, 14L5; Siemens Healthineers); beamformed (delay-and-sum (DAS), Lu’s-fk and Stolt’s-fk) for each steering angle, and coherently compounded. For comparison, images were recorded by CFI (10, 35 mm focus). Image quality metrics were obtained in images of a multipurpose phantom (CIRS Model057). We have just initiated a reader study (n = 200) to investigate how these phantom results translate to in vivo. Phantom results showed that contrast sensitivity (CS) and resolution (CR), lateral resolution (LR) and contrast-to-noise ratio (CNR, depth < 45 mm) were similar for CPWCI and CFI (10, 35mm) for both transducers, whereas CNR (>45 mm), LR and penetration were improved. In CPWCI, Lu’s f-k and DAS resulted in optimal CS (10L4) and LR, and CNR, respectively. In the ongoing reader study, image quality of breast lesions will be evaluated.
Comparison of the relative performance of three ultrasonic backscatter parameters measured in vivo at the femoral neck
Authors: Hoffmeister Brent K. , Delahunt Sarah I. , Downey Kiera L. , Viano Ann M. , Newman Will R. , Thomas Doni M. , Georgiou Loukas A. , Gray Aubrey J. , Main Evan N. , Pirro Gia
Published: November 2021

The global impact of osteoporosis as a major public health problem has generated interest in developing ultrasonic techniques that can be used to screen populations for this bone disease. The goal of this study was to assess the relative performance of three ultrasonic backscatter parameters: apparent integrated backscatter (AIB), frequency slope of apparent backscatter (FSAB) and frequency intercept of apparent backscatter (FIAB). Measurements were performed at the left and right femoral necks of 88 healthy volunteers using an ultrasonic imaging system equipped with a 3 MHz convex multi-element transducer. Backscatter signals from the femoral neck were captured for analysis. AIB was determined from the frequency averaged power in the backscatter signal compensated for the frequency dependent response of the measurement system. FSAB and FIAB were determined from the slope and intercept, respectively, of a line fitted to the compensated spectrum. Linear regression analysis was used to compare measurements performed at the left and right femur. All three parameters demonstrated similar and highly significant (p < 0.000001) correlations between left and right side measurements (RAIB = 0.62, RFSAB = 0.56, RFIAB = 0.51) indicating that they are equally sensitive to naturally occurring variations in the ultrasonic properties of the femoral neck.
Measuring signal quality in low power wearable ultrasound imaging
Authors: Acuña Samuel A. , Bashatah Ahmed , Chitnis Parag V. , Sikdar Siddhartha
Published: November 2021

Frequency Modulated Continuous Wave (FMCW) ultrasound is an emerging imaging method adapted from radar that can be implemented in wearable ultrasound systems due to the reduced size, power, and signal processing requirements. Acoustic reflections are encoded in the frequency domain, and thus evaluating signal quality currently requires extracting frequency information from a time-varying acquisition signal, which requires additional signal processing. Question: Can we differentiate FMCW ultrasound signal quality using an acquired FMCW time-series? We collected FMCW ultrasound images with a custom ultrasound transducer contacting and losing contact with tissue, to simulate moments of poor signal quality. We used two potential time-domain signal quality metrics: the mean absolute value (MAV) of the signal, and Sample Entropy. Sample Entropy is an information theory method for assessing complexity in a time-series. Both MAV and Sample Entropy could differentiate when the transducer was in good contact with the tissue. MAV required less processing time, but Sample Entropy had less noise when the transducer lost contact. FMCW ultrasound imaging is a promising imaging method that has application in wearable ultrasound systems, and FMCW ultrasound signal quality can be assessed in the time-domain without extracting frequency information. [Work supported by NIH 5U01EB027601-02.]
Model validation in the test and evaluation community: Current practices
Authors: Pees Edward
Published: November 2021

Computer modeling and simulation (M&S) continues to play a growing role in the acquisition lifecycle of commercial systems throughout every stage from developmental testing to operational evaluation. During system development, M&S may be used to evaluate options for meeting performance requirements. For operational systems, M&S may be used to enable the design of physical experiments aimed at assessing operational effectiveness, suitability, or durability. When performing actual system testing, M&S is often useful for reinforcing conclusions drawn from experimental measurements by supplementing test results, or simulating test cases that are experimentally inaccessible. Given the high value of decisions that may be based on the outcomes of these and other types of simulations, the need for a rigorous verification and validation (V&V) process becomes evident. This presentation provides an overview of the basic design and analysis techniques that are being promoted by the operational testing community to perform quantitative comparisons of simulation and experimental data. As advances in computing technology lead to more extensive use of M&S for supporting system assessments, stakeholders will require more extensive use of defensible validation practices. The focus of this presentation, therefore, is to provide an overview of the process, required data, and statistical techniques recommended for validating complex acoustic models.
Validation of a sonic boom model through atmospheric turbulence with flight test data
Authors: Lonzaga Joel B.
Published: November 2021

This paper presents a validation of an extended Burgers equation that accounts for mean scattering effects of turbulence in the atmospheric boundary layer (ABL). The scattering effects are calculated from a scattering wavenumber formulated using the multiple scattering theory and are incorporated as an additional linear term in a Burgers equation commonly used to model sonic boom propagation. The scattering wavenumber represents the interaction of an acoustic wavefield, including backscattering, with a turbulent field and gives rise to signal attenuation and distortion. Numerical models obtained using the extended Burgers equation are compared to measured sonic booms from conventional supersonic aircraft. The acoustic measurements are supplemented by measurements of the turbulence conditions as well as the thickness of the ABL. Results show that the mean effects of scattering on sonic booms smooth out shocks in the waveforms, reduce the peak amplitudes, and thus reduce the loudness. The results also indicate that the loudness reduction is dependent on the variance, correlation length, and thickness of the turbulent field. The performance of the extended Burgers equation is compared to that of existing signal processing-based approaches developed to represent turbulence effects on sonic booms through the ABL.
A Helmholtz equation implementation for finite element method based on FEniCS project
Authors: Velasco-Segura Roberto , Martínez-Lule Cristian U.
Published: November 2021

Many systems in acoustics have relevant stationary states, which can be described using the Helmholtz equation. In this work we present an implementation of the Helmholtz for Finite Element Method based on FEniCS Project. Even when this is a single equation, the modeling of different systems requires different versions of it, regarding: domain of the involved variables, dimensionality, symmetry, boundary conditions, and homogeneity of the media (including parameters related to attenuation). Accordingly, these versions require different parts of the code to be adjusted. We present a set of examples, with increasing complexity to incorporate a variety of situations, and a convergence test against analytic solutions for some representative cases, which show some of the limitations of the code. Even when this code is presented with simple examples for clarity, its usage is not limited to this scope, it has successfully been used for research projects, which are briefly mentioned as well. The code is provided with the same open source license as FEniCS Project. [This work was supported by UNAM-PAPIIT TA100620.]
Application of Monte-Carlo simulations for validating adaptive psychophysical procedures
Authors: Shen Yi
Published: November 2021

In psychoacoustics, data collection from human listeners is commonly done by adaptively varying the stimulus parameters according to the data collected from preceding trials during an auditory task. Compared to the method of constant stimuli, the adaptive procedures allow the adjustment of stimuli for individual listeners to achieve a desired performance range. The adaptive procedures may be designed to estimate performance thresholds, psychometric functions, or the parameters of psychophysical models. The algorithms within these procedures that govern the selection of stimulus parameters may be based on heuristics or Bayesian active learning, and they may differ in terms of computational complexity, accuracy, reliability, stability, and rate of convergence. Choosing an appropriate adaptive procedure for a specific application can be assisted by Monte-Carlo simulations, in which candidate procedures are run on simulated listeners whose responses are governed by ground truth psychometric functions or psychophysical models. The estimated model parameters can be then compared to the ground-truth parameters to evaluate the performance of each adaptive procedure. In this presentation, an introduction of this approach will be provided with examples from psychoacoustics. The analysis techniques that address accuracy, reliability, stability, and rate of convergence will be discussed.
Shallow water transmission loss inversion for seafloor characterization
Authors: Albritton James , Gunderson Aaron M.
Published: November 2021

A Bayesian inference algorithm has been developed for seafloor geoacoustic parameter determination through analysis of transmission loss measurements taken in shallow water environments. It uses a parallel tempering scheme for improved parameter space sampling and bias reduction, and evaluates ray acoustic forward models in Bellhop. The algorithm is verified by application to synthetic data generated using finite element and ray acoustic propagation models for frequencies from 0.5 to 5 kHz. Verification is assessed through the ability to recover inversion parameter values prescribed within the synthetic data, and inspection of ambiguous inversion situations. Initial inversion parameters include bulk sediment density, sound speed, and attenuation, as well as ripple height and wavelength for some seafloors. The inversion yields posterior probability distributions for each inversion parameter, which inform parameter resolvability and covariance. Algorithm accuracy, efficiency, and applicability to data from different ocean environments will be discussed. [This work has been supported by the Office of Naval Research, Task Force Ocean.]
Reproducible excitation of string instruments using a robotic arm
Authors: Pàmies-Vilà Montserrat , Mayer Alexander , Chatziioannou Vasileios
Published: November 2021

In string instruments, while the vibrations of the wooden bodies can be mostly described as linear, the excitation mechanism is usually nonlinear. For instance, the frictional forces that excite bowed-string instruments have undergone both theoretical and experimental studies due to the underlying complexity. In order to analyze the vibratory behavior and the radiation pattern of musical instruments, it is often necessary to excite the instruments repetitively under controlled conditions, for which artificial means are customarily used. In this work, the sound production in string instruments is studied with the usage of a computer-controlled robotic arm, which provides high precision in positioning as well as controlled motion with 6 degrees of freedom. Together with a customized 3D-printed clamp-system, it is possible to hold and move objects in order to mimic the gestures of instrumentalists, equipping the arm, for example, with a bow or a plectrum. This systematic experimental approach allows to repeatedly reproduce the player-instrument interaction, either by accurately recreating the player actions or by precisely adjusting one or several control parameters. In this study, the possibility to introduce such a robotic arm for the investigation of string instruments is presented and exemplified using different case studies.
Nonlinearities in the singing voice
Authors: Titze Ingo R.
Published: November 2021

The vocal ligament and the thyroarytenoid muscle are the vibrating elements that control fundamental frequency in singing. Their stress-strain relations are highly nonlinear. For a 3 octave fo range, it requires an exponential rise in stress of the form eBε, where ε is the strain. The exponent B must be greater than 8.0 if there is a 2:1 vocal fold length change. There are also strong interaction nonlinearities. Maximum acoustic and aerodynamic power is transferred from the source to the airway if the glottal impedance approaches the airway impedance. The airway impedance can be controlled with the epilaryngeal airway, which acts like the mouthpiece of a trumpet.
Spectral content of the attack portion of the tone produced by a soprano recorder
Authors: Giordano Nicholas , Thacker Jared W.
Published: November 2021

We have used Navier-Stokes-based modeling to calculate tones produced by a full-size soprano recorder. Of all the wind instruments, the player of a recorder has relatively little impact on the tone that is produced. However, one thing that the player does control is the way that the blowing pressure is increased from zero at the start of a tone to a final value that is maintained until the end of the tone. We show how the ramp-up time for the blowing pressure has a profound effect on the spectral content of the attack portion of the tone. Using a correlation analysis, we explore this spectral content and consider how it can, in certain blowing regimes, be an important and audible contributor to the tone color produced by a recorder. [Work supported by NSF grant PHY1513273.]
Measurements and simulations of sung multiphonics on a trombone played by an artificial mouth
Authors: Page Christopher , Gilbert Joël , Woolley Alan , Campbell Donald M.
Published: November 2021

Playing a sung multiphonic on a brass instrument is a specialised technique in which the performer sounds one pitch through lip vibration while simultaneously singing a different pitch. The result is typically a complex sound in which several different pitches are audible. A full acoustical description of the sound generation process would include the mutual interactions of the two nonlinear flow valves (vocal folds and lips), the player’s windway resonances, and the resonances of the instrument. Velut et al. (JASA 2016) reported measurements of mouth pressure, pressure inside the mouthpiece, and radiated sound while a trombone player performed various sung multiphonics. A simplified time domain simulation model replacing vocal folds and windway by a sinusoidal source was partially validated. In the present work the human player has been replaced by an artificial mouth, allowing the “sung” mouth pressure to be provided either by a sinusoidally excited loudspeaker or a human singer. Results are broadly in agreement with those of Velut et al., and with time domain simulations using sinusoidal forcing in the mouth cavity.
Constrained continuation of a physical model of brass instrument
Authors: Fréour Vincent , Guillot Louis , Masuda Hideyuki , Vergez Christophe , Cochelin Bruno
Published: November 2021

Constrained continuation is a method allowing some constraints to be applied to bifurcation diagrams, while relaxing some parameters of the model, which then become new unknowns of the system. Applied to a physical model of wind instruments, this method allows some constraints to be applied to a solution branch, and the evolutions of the relaxed parameters to be computed along this solution branch. We apply this approach to a physical model of trumpet, where constraints on the playing frequency and on the amplitude of the internal pressure with respect to the mouth pressure are established from experimental measurements on a trumpet player. By relaxing different parameters of the model, it is possible to approximate the behavior of the trumpet player using constrained continuation, and to quantify the variations of the model parameters that are necessary to fulfill the constraints. Application to different trumpet models reveal differences between instruments, that are confronted to some preliminary perceptual evaluations.
Relationship between vessel speed and sounds levels in the Bering Strait
Authors: Escajeda Erica D. , Stafford Kathleen , Woodgate Rebecca , Laidre Kristin L.
Published: November 2021

Vessel speed limits have been proposed as a means of reducing underwater ship noise, however it is unclear how effective such a measure would be in the Bering Strait, a natural bottleneck for ships transiting into the Arctic from the Pacific Ocean. In this study, we examine how ship noise varies with vessel type and speed using Automatic Identification System (AIS) data collected from vessels traveling through the strait along with acoustic recordings from three moored hydrophones. We matched recordings with ship noise to individual vessels that passed within 100 km of each hydrophone in June through November 2013–2015. A total of 69 sound files were analyzed and matched with individual vessels, with tug (n = 21) and cargo ships (n = 18) as the most common vessel type observed in our dataset. Sound levels for each vessel were calculated and compared as a function of vessel type and speed. The results of our study could inform policymakers and managers on the effectiveness of vessel speed limits on reducing ship noise in a sensitive Arctic habitat.
Transmission loss calculation of a pipe with dissipative silencer containing porous materials
Authors: Yang Haesang , Lee Jongmoo , Lee Chul-Won , Seong Woojae
Published: November 2021

Various types of silencers have been used to reduce noise transmitted through pipe system. In particular, a dissipative silencer containing absorbing materials inside has an ability of noise control by transferring acoustic/vibrational energy to thermal energy. In this study, the acoustic performance of a dissipative silencer lined with two-layer absorbing materials is investigated. Herein, the absorbing materials in the form of a polymer foam are considered as a porous medium composed of a solid polymer skeleton and internal pores. From the boundary conditions at the rigid wall and the interfaces between the porous materials, eigenvalues and eigenfunctions in the dissipative silencer are determined. Finally the transmission loss is obtained through the mode matching method. The effects of geometry and acoustic properties of the porous medium are also discussed.
Evaluation of Ashrae background noise criteria through in situ measurement
Authors: Rawlings Samantha , Lo Verde John , Dong Wayland
Published: November 2021

Chapter 49 of the ASHRAE Applications Handbook establishes background noise design criteria for typical interior occupancies. These criteria are referenced and commonly used as an acoustical basis of design for codes, such as the International Green Construction Code, and for rating systems, such as LEED, as well as other project documents and design standards. They are set forth to determine the level of occupant comfort from mechanical systems. The authors have observed that compliance with these standards is not always necessary to avoid complaints. In fact, the benefit of compliance with the standards is limited to the protection of the acoustician, rather than meeting needs for the users of the space. This observation has motivated the authors to assess the established ASHRAE criteria as compared to measured interior sound levels with HVAC systems in operation. The authors will present objective data associated with noise measurements in specific HVAC applications. Using data from subjective determinations, the authors will propose a system for determination of occupant reaction that can be considered.
Encoding, reconstruction and representation of natural vocal communication signals
Authors: Theilman Bradley , Gentner Tim
Published: November 2021

How complex, natural communication signals are represented in the activity (spiking) patterns of neural populations is not well understood. I will describe data from a series of experiments that examine the spatiotemporal pattern of song-evoked spiking in large populations of simultaneously recorded neurons in the secondary auditory cortices of European starlings (Sturnus vulgaris), a species of songbird. Single neurons in these regions display composite receptive fields that incorporate large numbers (a dozen or more) orthogonal spectro-temporal features matched to the acoustics of species typical songs. This observation implies that the independent spiking response of any single neuron at any point in time is somewhat ambiguous with respect to the stimulus. I will discuss how this ambiguity can be resolved at the population level by considering an alternative representation of underlying latent stimulus space and the coincident pattern of firing among small groups of neurons. I show how this approach allows for high-fidelity reconstruction of spectrographic representations of novel birdsong from spiking responses. I then show how these coincident patterns of spiking can be measured directly in arbitrarily large neural populations, without reference to receptive fields, and conclude by discussing the implications of this combinatorial population encoding for the nature of perceptual representation.
Neural dynamics of the motor system during language development
Authors: Clarke Maggie , Bosseler Alexis , Zhao Tian , Kuhl Patricia K.
Published: November 2021

Motor and sensory cortices are traditionally thought to be functionally separate systems. However, many studies have shown their roles in both action and perception to be highly integrated. In particular, this has been observed in regard to speech, where listening to speech sounds elicits neural activity in motor regions of the brain. Two datasets containing magnetoencephalography (MEG) data from 2-, 6-, 7-, and 11-month-old infants were used to investigate the role of the motor system in speech perception throughout various stages of language development. We examined the relationship between activation in auditory sensory and motor regions of the brain with respect to: (1) the development of neural responses with increasing age, and (2) potential differences between speech and nonspeech auditory signals. Results showed that motor regions are activated during speech perception across all ages. At 2 months of age, infants show activity in both motor and motor planning regions in response to speech, but not nonspeech, acoustic stimuli. Our data suggest that infants’ activation of sensory and motor brain regions in response to speech does not require experience producing speech.