bluuebunny/crossref_metadata_2025 huggingface dataset:
Towards a comprehensive model of binaural processing
Authors: Dietz Mathias , Eurich Bernhard , Klug Jonas , Encke Jörg
Published: November 2023

Most classic models of binaural processing are partly built on assumptions that have been challenged or even contradicted by physiologic or psychoacoustic data. For example, that delay lines encode interaural time difference (ITD), that “binaural filters” are wider than auditory filters, or that the binaural system is sluggish and cannot encode rapidly changing ITDs. While these assumptions have been motivated by psychoacoustic data, they have also been contradicted by other psychoacoustic data. The present study revisits and challenges the respective reasonings. One result is that the psychoacoustic proof of delay lines contained an unmet assumption. Instead of “sometimes wider filters” we propose a spectral incoherence interference mechanism that appears to resolve the impasse of inconsistent filter bandwidth requirements. In the temporal domain, we model fast ITD encoding and binaural sluggishness is realized by slow reformation of the interaural statistics of auditory objects. The resulting model still has some unproven assumptions; however, it does not need to change its parameters depending on the type of stimulus or task. As the binaural filter bandwidths and processing speeds are now equivalent to their monaural counterparts and consistent with physiological findings, the model may be instrumental in moving to a more unified understanding of auditory processing.
The effect of angular disparity between sound source sequences on the perceptual organization of auditory objects
Authors: Sakamoto Shuichi , Tamakawa Maho
Published: November 2023

Within auditory scene analysis is a well-known streaming phenomenon which is observed when listeners group several sounds into “auditory objects” in complex auditory scenes. When two auditory sequences consist of similar sounds, these sequences tend to be perceived as a single stream, but can form segregated streams when the sounds are presented from disparate angles. This study investigated the tolerance thresholds for the angular disparity at which the sound sources would segregate rather than group together into single auditory objects, when 50-ms one-third octave bands of noise were presented in the horizontal plane with changing azimuth angle. Listeners were asked to judge whether the presented noise sequences were perceived as a single stream or not. The results revealed that listeners tend to perceive the presented sequences as a single stream when the angular disparity between noises was small; however, these tolerance thresholds depended on the spatial region within which the sequences were presented. Tolerance thresholds became large when the noise sequences were presented from the side, in comparison to the situation when sequences were presented from in front of the listeners. Results were consistent with the minimum audible angle on the horizontal plane.
Disrupting perceptual anchoring to pure-tone sequences in human listeners
Authors: Shulver Kurt , McAlpine David , Badcock Nicholas A. , Hernandez Perez Heivet
Published: November 2023

Perceptual anchoring, a process akin to statistical learning, occurs rapidly and without conscious awareness and is integral to our ability to successfully navigate a noisy world. Here, we investigated anchoring abilities in typical hearing and reading participants by implementing an anchoring paradigm (Agus et al., 2014) using rapid pure-tone sequences (Barascud etal., 2016). We then attempted to disrupt anchoring by applying rapid transcranial magnetic stimulation (rTMS) to frontal cortical regions—areas implicated in the processing of and integration of tone sequences (Abla and Okanoya, 2008). Pure-tone sequences consisted of 50 ms tone-pips that were arranged according to two segments, random (RAND) and regular (REG). RAND segments were generated as tones of random frequencies, and REG segments were generated as in RAND but were iterated to create a repeating pattern. Sequences were presented across three conditions: REPfixed (identical sequences repeated across trials), REPnovel (identical sequences not repeated across trials), and NonREPnovel (nonidentical sequences not repeated across trials). We observed a significantly higher sensitivity to REPfixed relative to REPnovel across all participants (i.e., an anchoring effect). The disruption of frontal regions using rTMS did not significantly impact overall performance but did alter how participants completed the task over time.
Extending existing models of cochlear mechanics to emphasize physiological mechanisms that support innate perception of harmonic relations among pure tone frequencies
Authors: Biswas Amitava
Published: November 2023

Tonotopic mapping along the basilar membrane of the cochlear organ of Corti naturally supports a consistent relationship between the physical frequency of a tone and its perception of pitch. For example, higher frequencies tend to be mapped to higher pitch perceptions. Nevertheless, a precise perception of harmonic relations among pure tone frequencies apparently lacks a strong foundation on the tonotopic mapping mechanism alone. We are presenting a supplementary hypothesis based on temporal delays and cross-correlations between delayed signals in the cochlear fluids and the surrounding structures that provide a robust mechanism to establish innate perception of applicable harmonic relations among pure tone frequencies.
Influence of cortical inhibition on auditory efferents in humans
Authors: Leaver Lilly A. , Hernandez Perez Heivet , McAlpine David , Boothalingam Sriram
Published: November 2023

Auditory activity in humans is influenced by feedback networks in the brain. The final leg of this pathway originates in the brainstem and plays an important role in protecting and aiding communication in competing noise. Previous studies have used auditory and/or visual attention tasks to manipulate cortical activity when exploring its influence on the periphery via the auditory efferent system. Using subjective attention does not control for variability across individuals in attentional state, alertness, and arousal. Hence, a consensus on the relationship between cortical activity and how it influences more caudal efferent reflexes is still needed. Here we describe the first assay to non-invasively influence the human auditory cortex activity using repetitive transcranial magnetic stimulation and measure its consequence on peripheral structures using otoacoustic emissions. We hypothesized that depressing brain activity temporarily affects auditory functioning. By instigating a virtual cortical lesion in normal hearing participants, we were able to characterize the influence that the auditory cortex has on the sensory cells in the cochlea, mediated via the medial olivocochlear reflex. Our results will open avenues for further research into new diagnostic and therapeutic approaches for hearing disorders.
Measurement of distortion-product otoacoustic emissions at low frequency and effect of contralateral acoustic stimulation on its level
Authors: Koike Takuji , Hara Yuta , Lee Sinyoung
Published: November 2023

Measurement of distortion-product otoacoustic emissions (DPOAEs) is one of the functional tests for the outer hear cells in the cochlea. Since the sound levels of the DPOAEs are quite low, it is easy to be buried in noise especially in the low frequency range, and frequency analysis and time averaging are required to detect them. In this study, focusing on the frequency stability of two stimulus sounds and a most prominent DPOAE-component, we tried to reduce noise floor and shorten the measurement time by choosing an adequate time window length for averaging the sound pressure waveform in the ear canal and the number of the averaging. As a result, it has become possible to measure DPOAEs at the low frequencies around 300 Hz in a relatively short time. Using this method, the changes in the DPOAE level induced by contralateral acoustic stimulation, which are caused by medial olivocochlear reflex, were measured. Although some exceptions were observed, the DPOAE was suppressed with increasing the sound pressure of the contralateral stimulus, and the degree of suppression was greater for the lower-frequency DPOAEs.
Comparison of different auto-detection methods for wave V with a wireless automated auditory brainstem response (AABR) measurement system
Authors: Wu Chao-Min , Peng Kang-Cheng , Yang Ming-Xiu
Published: November 2023

The wireless automatic auditory brainstem response measurement system developed in the previous research uses Kalman filter with exponential weight averaging method (Kalman filter with EWA) to filter signal and used the differential method to detect the Wave V of ABR. However, the signals are too noisy to be accurately determined. Therefore, this study compares the Wavelet Kalman filter and Moving average to the Kalman filter with EWA, and the fitted parametric peak (FPP) to the differential method, respectively. The simulation results showed that the signal-to-noise ratio of ABR is the highest after Wavelet Kalman filtering, and the audiologist can mark the waves III and V of ABR the most. The latency of the wave V detected by FPP was used to calculate the Pearson product-moment correlation coefficient with the audiologist’s manual mark. The two latencies are highly correlated, and the correlation coefficient is higher than the differential method. Therefore, the Wavelet-Kalman filter and FPP algorithm were implemented in the AABR measurement system. To evaluate the accuracy of the algorithm in this study, subjective experiments were conducted with four normal hearing subjects. The Mann-Whitney U test was used to test thedifference between the average value of automatic detection and reproducibility.
The frequency modulation transfer function provides supplemental measures for the objective evaluation of pitch extractors
Authors: Kawahara Hideki , Sakakibara Ken-Ichi , Yatabe Kohei
Published: November 2023

We propose to apply the frequency modulation transfer function as a supplemental measure for evaluating pitch extractors' performance. We introduced a new family of time-stretched-pulse for acoustic system analysis (Kawahara and Yatabe, ICASSP2021, called CAPRICEP). Composing a test signal using the CAPRICEP units by Walsh-Hadamard sequence enables simultaneous measurement of the linear-time-invariant, non-linear-time-invariant, and random-time-varying attributes. We applied the proposed analysis method to eighteen pitch extractors and visualized their behavior (represented more than five thousand plots) as a movie. The proposed procedure will be available as open-source tools in our GitHub repository.
Frequency shifting of transmitted ultrasound in thick composites containing fiber wrinkles and its application in non-destructive evaluation
Authors: Cao Andong , Zhang Zhen , Li Qian
Published: November 2023

Thick composite structures are prone to defects such as fiber wrinkles and voids during manufacturing. It is challenging to accurately evaluate the forming quality of the structures using conventional ultrasonic inspection, due to the coupling effects between time-frequency features of ultrasound and mixed-type defects. Propagation behaviors of through-thickness transmitted ultrasound in thick composites with fiber wrinkles, voids and no defects were comparatively investigated by both simulation and experiment in this study. Influence of out-of-plane fiber wrinkles on the ultrasonic frequency shifting was studied by comparing the time-frequency characteristics of simulated ultrasonic signals after propagating different distances in the intact and wavy composites. Changes of transmission coefficients of converted transverse waves caused by fiber wrinkles were concluded be the reason for the appearance of high-frequency components above the excitation frequency in the transmitted ultrasound signal. Thereby ultrasonic defect inspection indices based on the phenomenon of ultrasonic frequency shifting were defined. Effects of interaction angles between ultrasonic propagation direction and fibers on the defined inspection indices was further investigated quantitatively. The thick composites with diverse defects were successfully diagnosed using the ultrasound frequency shifting and energy dissipation behaviors.
A real-time auralization framework for scientific experiments
Authors: Schaefer Philipp , Aspoeck Lukas , Palenda Pascal , Fels Janina , Vorlaender Michael
Published: November 2023

The software Virtual Acoustics (VA) is an open-source auralization framework developed at the Institute for Hearing Technology and Acoustics, RWTH Aachen University, Germany. Using physics-based models for source emission and sound propagation, it allows plausible rendering of virtual scenes based on purely synthetic data. Its modular design provides a variety of rendering modules using different assumptions for the sound propagation. This allows the rendering of various indoor and outdoor scenarios with adjustable degree of complexity. Based on a similarly modular concept, VA allows a flexible way of reproducing the sound via headphones or loudspeaker arrays. For this purpose, the signals can be spatialized using binaural synthesis, higher-order ambisonics or VBAP. The respective scenarios, including source and receiver movement, can be controlled using the C + +, C#, Matlab, Python programming languages. Additionally, there are interfaces for the Unreal and Unity game engines allowing the combination with sophisticated visual cues, e.g., using HMDs. The software’s flexible structure and configuration possibilities enable the controlled application in listening experiments while providing an adequate level of plausibility. This work discusses the options as well as the limitations of the software and presents application examples in scientific experiments.
Divided spectro-temporal transformer for sound event localization and detection in real scenes
Authors: Shul Yusun , Choi Jung-Woo
Published: November 2023

Sound event localization and detection (SELD) involves the detection of sound events (SED) and the estimation of their direction of arrival (DoA) by utilizing multichannel sound signals. Recent research in SELD has predominantly focused on deep neural network (DNN) based models, which specifically emphasize learning temporal context. Examples of these models include the convolutional recurrent neural network (CRNN) and the ResNet-conformer architecture, which handle spectral and channel information only as the embeddings of temporal features. To fully exploit spectral information providing a crucial cue for both SED and DoA, it is imperative to devise a network architecture that effectively learns both spectral and temporal contexts. In this regard, we propose a divided transformer architecture that separately identifies the spectral and temporal context to encourage the model to learn more spectral characteristics of signals while retaining the temporal context. The efficacy of the divided spectro-temporal transformer approach is validated using the DCASE 2022 and 2023 challenge task 3 datasets. Furthermore, a series of parameter studies carried out to optimize the performance of SELD demonstrates that the number of frequency bins for attention and the pooling location impact the performance, and the divided spectro-temporal transformer is beneficial for both SED and DoA.
Cancer ablation with histotripsy
Authors: Hall Timothy L. , Xu Zhen
Published: November 2023

Histotripsy is an ablation method using mechanical action of cavitation bubbles to fracture cells and tissue structures as a non-invasive cancer treatment for tumor masses occurring at locations in the body with a suitable acoustic window. Non-thermal ablation modalities including histotripsy have been shown to enhance immune system stimulation with potential for anti-tumor benefit beyond the targeted volumes. This talk will give an overview of histotripsy cancer research to date treating cancer models and early clinical trials. Key areas of research include instrumentation for treating rodent models, best strategies for spatial-temporal dosing of histotripsy, and working to understand the mechanisms of immune stimulation to best take advantage of abscopal effects and adjuvants for combination therapy. We have constructed several precision histotripsy systems for targeting subcutaneous and orthotopic tumors in mice and rats using a combination of ultrasound, MRI, and stereotactic guidance. Evidence to date has shown the strongest immune stimulation occurrences with moderate cavitation doses. Histotripsy ablation studies show stimulation of tumor-specific immune responses capable of magnifying the impact of checkpoint inhibition immunotherapy.
Delivery of ultrasound cavitation therapy with a modified clinical scanner
Authors: De Koninck Lance H. , Krolak Connor , Vuong Kaleb , Powers Jeffry , Averkiou Mike
Published: November 2023

Ultrasound-induced bioeffects from stable and inertial cavitation of microbubbles in tumors have been shown to enhance systemic drug delivery. However, the high pressures and long cycle lengths needed for cavitation treatment are not available on current clinical ultrasound scanners. Here, we implement acoustic conditions (1.6 MHz, 12-500 cycles, <3 MPa, 10-200 Hz PRF) suitable for cavitation treatments (USCTx) on the S5-1 probe of a Philips EPIQ scanner. Hydrophone measurements confirmed the acoustic conditions. Passive cavitation detection (PCD) in solutions and tissue mimicking phantoms containing microbubbles demonstrated the spatial and temporal extent of the produced cavitation with 20 consecutive pulses. Inertial cavitation was observed at peak negative pressures of ∼0.5 MPa and ∼0.9 MPa in the solutions and phantoms, respectively. At low PRFs (<100 Hz), inertial cavitation was only observed within the first 5-10 pulses for both media, suggesting USCTx may generate most bioeffects in the first few pulses. The higher PRFs sustained cavitation activity for a greater duration, consistent with gas diffusion of micron size bubbles after shell disruption with the first pulse. Having implemented USCTx with a clinical scanner and confirmed the produced cavitation in vitro, we plan to evaluate this technique in an upcoming mouse study.
The listening brain's response to adversity
Authors: McMahon Catherine
Published: November 2023

How the brain hears, responds to adversity, and adapts with hearing interventions, can inform clinical decisions, device design and, ultimately, broader policy and practice. While audiological practice today remains focused on the use of a limited test battery, improving assessment techniques to identify how well adults comprehend speech in across a range of listening environments (and beyond the pure tone audiogram) can lead to greater personalization of treatments, devices, and rehabilitation. Moreover, understanding how the brain responds to interventions, such as cochlear implants or rehabilitation programs for tinnitus, could improve our understanding of which work, and for whom. In this presentation, I discuss a number of experimental techniques that we have used to explore how the brain responds to sound under challenging listening conditions using speech-in-noise and vocoded stimuli. In addition, I will discuss how the brain adapts after cochlear implantation for those with significant hearing loss, and following a 30-week rehabilitation program for those with significant tinnitus. Finally, potential limitations of electrophysiological measures within current clinical assessment batteries will be considered, as well as opportunities to better understand how we can improve hearing healthcare for individuals and populations.
Investigating the behavior of the slow dynamic recovery at early times
Authors: Yoritomo John
Published: November 2023

Slow dynamics (SD), a type of non-classical nonlinear elastic behavior, is characterized by (i) a material softening due a minor mechanical conditioning and (ii) a subsequent slow recovery that approaches the original macroscopic elastic state. Early work in sandstones and other consolidated granular materials—and more recent work in unconsolidated granular materials—have found the recovery to be logarithmic-in-time, at least for seconds to hours after conditioning. However, other recent studies have observed recoveries in consolidated granular materials that deviate from log(time), particularly for early recovery times. This talk will present experimental investigations in to the nature of the SD recovery, especially at early times. The experimental venue will be the single bead system (a single bead confined between two large plates of a similar material) introduced previously. We will measure SD recoveries using multiple methods, such as Dynamic Acoustic Emission Testing (DAET) and Larsen Monitoring, to better compare our experiments with previous work. The effect of different conditioning mechanisms on the early time recovery will also be investigated. The presentation will conclude with some discussion of proposed mechanisms for slow dynamics.
Evaluation of the Fresnel approximation for the longitudinal particle displacement in shear wave beams
Authors: Kaufinger Philip G. , Archer Branch T. , Cormack John M. , Spratt Kyle S. , Hamilton Mark F.
Published: November 2023

The longitudinal particle displacement in shear wave beams generated with disks that vibrate longitudinally at several hundred hertz is used to assess stiffness of soft tissue in vivo. Nonlinear elasticity of tissue, although less commonly used than linear stiffness, may be a more sensitive or specific biomarker of disease. A mathematical model for linear propagation of both transverse and longitudinal motion in a shear wave beam in an isotropic elastic half-space, and comparisons with measurements in tissue-mimicking phantoms, was published earlier this year [Archer et al., JASA 153, 1591 (2023)]. When including elastic nonlinearity in a propagation model, the complexity is reduced substantially by deriving an evolution equation based on the Fresnel approximation [Zabolotskaya, Sov. Phys. Acoust. 32, 296 (1986)]. For application to elastography, the parameter space in which the Fresnel approximation provides an accurate description of the longitudinal particle displacement must be established. In this presentation, the accuracy of the Fresnel approximation is assessed for linear shear wave beams, both unfocused and focused, by comparison with the existing mathematical model. Attention is devoted primarily to the longitudinal particle displacement in nearly incompressible media. [PGK is supported by the ARL:UT Chester M. McKinney Graduate Fellowship in Acoustics.]
Corticofugal regulation of predictive coding
Authors: Lesicko Alexandria , Angeloni Christopher , Blackwell Jennifer , De Biasi Mariella , Geffen Maria
Published: November 2023

Sensory systems must account for both contextual factors and prior experience to adaptively engage with the dynamic external environment. In the central auditory system, neurons modulate their responses to sounds based on statistical context. These response modulations can be understood through a hierarchical predictive coding lens: responses to repeated stimuli are progressively decreased, in a process known as repetition suppression, whereas unexpected stimuli produce a prediction error signal. A potential substrate for top-down predictive cues is the massive set of descending projections from the cortex to subcortical structures, although the role of these corticofugal neurons in predictive processing has never been directly assessed. We tested the effect of optogenetic inactivation of the auditory cortico-collicular feedback in awake mice on responses of auditory midbrain neurons to stimuli designed to test prediction error and repetition suppression. Inactivation of the cortico-collicular pathway led to a decrease in prediction error and repetition enhancement in these neurons. Overall, our results demonstrate that the auditory cortex provides cues about the statistical context of sound to subcortical brain regions via direct feedback, regulating processing of both prediction and repetition.
Listening to the room: Disrupting activity of dorsolateral prefrontal cortex impairs learning of room acoustics
Authors: Hernandez Perez Heivet , Monaghan Jessica J. , Mikiel-Hunter Jason , Traer James , Sowman Paul , McAlpine David
Published: November 2023

Navigating complex sensory environments is critical to survival, and brain mechanisms have evolved to cope with the wide range of surroundings. In noisy spaces listeners place more emphasis on early-arriving sound energy, nevertheless, reverberant energy is highly informative about those spaces per se, and human listeners show improved speech understanding when re-encountering known reverberant environments. We assessed the ability of listeners to perceive speech (Coordinate Response Measure corpus) in noisy and reverberant rooms. We mimicked the acoustic characteristics of real rooms using loudspeakers positioned within an anechoic chamber. Listeners were also exposed to repetitive transcranial stimulation (rTMS) to disrupt the dorsolateral prefrontal cortex activity (DLFPC), a region believed to play a role in statistical learning. Our data suggest listeners rapidly adapt to statistical characteristics of an acoustic environment to improve speech understanding. This ability is impaired when rTMS is applied bilaterally to the DLPFC. The data demonstrate that speech understanding in noise is best when exposed to a room with reverberant characteristics common to human-built environments. Our findings provide evidence for a reverberation “sweet spot” and the presence of brain mechanisms that might have evolved to cope with the acoustic characteristics of listening environments encountered every day.
Physics-informed learning for modeling infrasound propagation in extreme weather conditions
Authors: Millet Christophe , Khoa Nguyen Thi Nguyen , Mougeot Mathilde
Published: November 2023

Extreme events in fluid flows are characterized by the coexistence of complex nonlinear dynamics, high intrinsic dimensionality and intermittency, which often results in spatially localized disturbances (turbulence spots, gravity wave breaking). Although many studies have shown that atmospheric ducting of infrasound is sensitive to these disturbances, yet the link between their statistical properties and that of the infrasound wavefield remains an open question, mainly because very little data are available for extreme events. The present work focuses on catastrophic events in climate systems where the amount of data available (typically a few decades) is not sufficient to extrapolate the PDFs. This class of problem involves geophysical fluid flows over climate scales where reanalysis data are a reliable source of information. In contrast to methods that rely on standard models to compute the PDFs from available data, the focus here is on data-driven methods that encode some information about the wave dynamics. The idea behind this approach is to combine two sources of information (reanalysis data and wave theory) using physics-informed neural networks to extrapolate the PDFs. The performance of this approach is illustrated around two types of events that affect infrasound propagation: sudden stratospheric warmings and mountain-induced extreme weathers.
Improving the acoustic contrast control performance in car cabins
Authors: Wang Shuping , Xu Qing , Zhu Qiaoxi , Tao Jiancheng , Qiu Xiaojun
Published: November 2023

The car cabin is an enclosure where personal audio is very important because different occupants may have individual listening requirements. Potential approaches to improve the acoustic contrast control performance in enclosures are discussed in this paper, including the configuration of loudspeakers and the sound absorption of sidewalls. The effect of the number of loudspeakers on the acoustic contrast control performance is first investigated, and the locations of a fixed number of loudspeakers are then optimized to maximize the acoustic contrast achieved with the system. The sound absorption of sidewalls also has an effect on the acoustic contrast control performance and it is discussed in detail. The simulations are based on the acoustic transfer functions obtained with a finite element model of a car cabin. The findings in this paper may serve as a guide to future designs of personal audio systems in car cabins.
Effect of reference value and ensemble size on perception of reverberation in simulated listening environments
Authors: Jasinski Christopher M. , Celmer Robert D.
Published: November 2023

Reverberation time is an important metric characterizing one of the key differences between performance venues caused by various furnishing, materials, and geometry within such spaces. To justify alterations to a venue, architects and acousticians refer to the just-noticeable-difference (JND) of reverberation time, cited in the ISO 3382-1 room acoustics standard as 5% of the reference value. This JND was determined experimentally using impulsive noise with varying reverberation. In real performance venues, overlapping and simultaneous sounds are more common than isolated impulses. As such, the JND noted in literature may not provide a complete picture of perceived reverberation for persons listening to live performed music. For this study, multiple test methods were evaluated by using different reference reverberation times as well as using a variety of instrumentation and genres for musical signals. Results were generated using test participants who were asked to listen to multiple virtual soundfields and provide subjective evaluation. Reverberant soundfields were recreated in an anechoic listening environment and auralizations were produced using ODEON room acoustics software. Results indicated statistically significant mean differences in perceived reverberation across instrumentation subsets, genre subsets, as well as through different testing configurations. [Work supported by The Paul S. Veneklasen Research Foundation.]
A novel method for optimizing in-car rolling noise levels within a railway tunnel environment
Authors: Zoontjens Luke , Sostaric Jelena
Published: November 2023

In-car noise levels within trains rolling on surface track are usually controlled by noise and vibration which is generated at the wheel–rail interface and then transmitted through the chassis and floor of the train cabin. In a railway tunnel environment, higher noises levels result from the build up of reverberant noise, and if left untreated this increased noise can affect passenger comfort and make it harder to listen or converse. In extreme cases, it can lead to adverse health effects: travellers may complain and avoid using the rail service as a result. Accordingly, the acoustic design of railway tunnel environments generally includes consideration of various treatments to reduce noise ingress into vehicle interiors, particularly given treatments to the vehicles themselves may not be cost effective. Modeling of in-car noise levels within tunnels has traditionally used the Sabine equation as part of the design process. Because the Sabine equation was never intended for this application given the geometry and frequencies involved, an improved method which recognized the near field effects was developed in order to provide confidence in the acoustic design. In this presentation, this novel method for modeling in-car rolling noise levels and optimizing sound absorptive treatments within a tunnel is discussed. Modeling results and measurements from a recent major rail project are used to demonstrate the effectiveness and improvements in outcomes from traditional approaches.
Room acoustic computer modeling—A case study to compare industry standard software with measured results
Authors: Hopkins Guy , Field Chris
Published: November 2023

This paper extends a previous publication presented at the Inter-Noise 2005 conference [1] and investigates the predictive performance of some industry standard room acoustic software packages compared with measurements. The case study specifically examines the Twyford Theatre, comparing predictions of room acoustic parameters obtained from ODEON, EASE, and Treble software with measurements. To conduct the study, impulse response measurements were performed in the theater using the swept sine method. Architectural drawings and on-site inspection measurements were utilized to construct ODEON, EASE, and Treble models for prediction purposes. The findings of this study provide insights into the predictive performance of these industry standard room acoustic software packages with comparison to measured results. C. Field and S. Shimada, Acoustic Computer Modelling: A Case Study to Compare Predictions by CATT and Odeon with Measured Results, Inter-Noise 2005.
Design and integration of acoustic treatment to the Former Stock Exchange—Cathedral Room
Authors: Butera Frank , Searle Helen , White Jim
Published: November 2023

The Gothic Bank Cathedral Room within the Former Stock Exchange located in Melbourne is architecturally significant and largely original displaying ornate features for a historical public business arena. The Cathedral Room was the main trading floor for the Stock Exchange and was designed to represent the interior of a church, highlighted by the vaulted roof, columns, and the stained-glass windows. Through the guidance of Heritage Council Victoria, the Cathedral Room was granted permission to be converted into a commercial dining room. This paper details the methodology adopted to reality capture the interiors of the Cathedral Room by deploying LiDAR laser scanning, to develop a room acoustics model, and to investigate mitigation options. Furthermore, it explores the link between applying appropriate acoustic targets, guiding stakeholders, and delivering the project, which is essential to operate a successful commercial business to meet the expectations of their cliental. Arup developed an Odeon model, which allowed for the placement of speech sources and receivers and with integrated mitigation options. The modeling was presented to stakeholders in Arup’s SoundLab, an ambisonic sound studio, allowing the stakeholders to listen to the untreated space and compare it to various levels of mitigation prior to progressing to detail design phase.
Evolution of acoustic methods for assessing and managing exposure of gray whales to sound pulses from seismic surveys off Sakhalin Island, Russian Far East
Authors: Racca Roberto , Hannay David E.
Published: November 2023

An effective program of estimation and mitigation of sound exposure from airgun array pulses is of vital importance when an endangered whale population forages in coastal waters near oil and gas production fields, where geophysical exploration campaigns regularly take place. Starting in 2001, increasingly sophisticated acoustic measurement and modeling techniques have been used for the environmental management of airgun array seismic surveys adjacent to the nearshore feeding grounds of the gray whale (Eschrichtius robustus) off the NE coast of Sakhalin Island, Russia. These monitoring data are also used in combination with visual observations for the analysis of the effects of sound exposure on whale behavior, distribution, and energetics. This talk follows two decades of evolution of the acoustic monitoring technology used in the Sakhalin studies, from rudimentary analog sonobuoys with limited bandwidth VHF telemetry, to digital stations capable of onboard signal processing and relaying of data via satellite to anywhere on the globe. In parallel, it traces the advancement of modeling techniques capable to fill the gaps between sparse measurement locations to yield high resolution estimates of the sound field from seismic sources operating concurrently at different, moving locations and in various regimes of ramp-up, production, or mitigation pulses.
Active Doppler monitoring of de novo cavitation induced by a dual-mode pulsed high-intensity focused ultrasound array
Authors: Williams Randall P. , Song Minho , Wang Yak-Nam , Totten Stephanie , Khokhlova Tatiana
Published: November 2023

Pulsed high-intensity focused ultrasound (pHIFU) is capable of inducing inertial cavitation in tissues without the need for microbubbles or other ultrasound contrast agents, thereby permeabilizing the tissue to enhance passive diffusion of systemically administered therapeutic agents. Here, we report on the use of ultrafast, synchronous power Doppler imaging to spatially map cavitation activity and resulting tissue disruption in ex vivo and invivo porcine tissues using a dual-mode imaging-therapy linear pHIFU array. The array (64 elements, aperture 51.2 mm × 14 mm, frequency 1.0MHz, 40% bandwidth) was driven by a power-enhanced Verasonics V1 system to deliver a series of 1 ms pulses at a 1% duty cycle while electronically scanning the pHIFU focus over an azimuthal range of ±1 cm. Plane wave Doppler ensembles were captured immediately after each pHIFU pulse to map the distribution and characteristics of the remnants of cavitation bubbles. The degree of resulting tissue disruption was assessed by histology and was correlated with cumulative Doppler power contours computed over the exposure region. The results show that ultrafast synchronous power Doppler is a promising approach for real-time quantitative monitoring of cavitational therapies. [Work supported by NIH R01EB023910 and T32DK007742.]
High quality low complexity binaural rendering for headphones
Authors: Brandenburg Karlheinz , Merten Nils , Thron Thomas , Sloma Ulrike
Published: November 2023

Playing back immersive audio via headphones has been a research topic for a long time. Although there have been advances, bigger breakthroughs are still missing. The basic idea of binaural rendering systems can be summarized with the following elements: The emission characteristics of the audio source, the transmission path from audio source to listener as well as suitable head related transfer functions. Systems following this basic paradigm range from dummy head stereophony over purely simulation based approaches to current parametric algorithms including the usage of room impulse responses. According to research in audio cognition, it is important to incorporate positional and rotational tracking data of the head close to real time as well as acoustic information about the listening room. Based on the chosen approach, the effort to acquire the measurements, to prepare the rendering or the computational demand of the rendering itself might be high. In this paper, we report on a low complexity rendering system which allows high quality binaural reproduction. A recent listening test and many reviews from listeners have proven, that the perception of the rendered audio signals is equivalent to listening to real audio sources in a room.
Generating 3-D auditory stimuli for the evaluation of spatial impression in musical instruments
Authors: Trevino Jorge , Ishimura Fusako , Tanaka Masaru , Shiozawa Yasuo
Published: November 2023

Spatial hearing plays an important, but not well understood, role in the perception of musical instruments and audio equipment. Psychophysical experiments are necessary to elucidate the processes which convey the spatial impression of sound sources. To this end, we propose a way to generate virtual stimuli for research on the spatial impression of musical instruments, specifically pianos. Our proposal, based on acoustical holography, takes a series of measurements over a dense grid and designs a virtual vibrating plate with the same directivity as the piano, as observed from the measuring grid. The number of active modes in the left-right and front-back directions of this virtual source can be controlled to reduce the radiation pattern complexity and generate a wide range of virtual stimuli. The resulting sound fields are rendered using binaural Ambisonics, using the position of the piano player as the spherical harmonic expansion center. The proposal was used in actual psychophysical experiments looking to shed light into the spatial impression of digital and acoustic pianos. The results show that the proposal does generate spatial sound signals which are consistently associated with different degrees of richness in the spatial impression.
Numerical simulation of flow-induced noise generation and propagation of a floating offshore wind turbine with prescribed pitch motion
Authors: Zha Ruosi , Wang Kai
Published: November 2023

It is important to evaluate flow-induced noise emitted due to operations of floating offshore wind turbines since noise pollution can damage the environments of seabirds and aquatic species. This paper studies the aerodynamic and aeroacoustic performance of a laboratory three-blade wind turbine model with an airfoil profile of NREL S826. The wind turbine blade rotation motion is coupled with the prescribed pitch motion of the floating offshore wind power platform. The influence of prescribed pitch motions on the noise generated by wind turbine blades and noise propagation was discussed. Adopting the computational fluid dynamics (CFD) method, the aerodynamic noise field on a blade is simulated by the improved delayed detached eddy simulation (IDDES) model and Ffowcs Williams–Hawkings (FW-H) acoustic analogy. The overset grid technique is adopted to simulate the six degrees of freedom (DoFs) motions of the floating offshore wind turbine model. The sound source distributions on blades for noise generation are obtained, and the flow-induced noise propagation characteristics are analyzed. It is found that the influence of the pitch amplitude and frequency on the flow-induced noise field as well as the wake vortex characteristics should not be neglected.
Real time GMAW weld bead profile mapping using acoustic sensing
Authors: Cullen Mitchell , Ji J. C. , Parnell Jeffrey
Published: November 2023

Monitoring the penetration profile of Gas Metal Arc Welding (GMAW) is critical in determining the overall quality and structural integrity of the produced weld bead. However, due to the instability and complexity of the GMAW process, it can be difficult to accurately monitor the weld bead formation and penetration profile. Due to this complexity, traditional methods for modeling the welding process, such as CFD analysis, are unable to be computed in real time. In this work, a new analytical method of estimating the weld bead penetration profile in real time using the sound signal is proposed. This method monitors the sound signal generated during the droplet transfer process to estimate both the heat input and material deposition into the weld pool. Using this estimation, a digital twin of the welding process is produced, allowing for the operator to monitor the weld bead formation in real time, guaranteeing the structural integrity of the final weld bead.
The UNSW tip clearance flow noise test rig
Authors: Awasthi Manuj , Wills Angus , Moreau Danielle , Croaker Paul , Dylejko Paul
Published: November 2023

A new test rig to measure the far-field sound, surface pressure fluctuations and flow-field in tip clearance flows has been designed at UNSW. The test rig is a part of the UNSW anechoic wind tunnel (UAT) and has been designed to allow studies of the tip clearance flow and sound radiation across a vast parameter space—tip clearance height, Reynolds number, angle of attack, and the tip geometry. This paper will present and discuss the design, characterization, and capabilities of this new test rig, along with some far-field sound results for a tip clearance flow formed by placing a stationary cambered airfoil adjacent to a wall. The measurements were performed for 51 different clearance heights at free-stream velocity of 30 m/s. The geometric angle of attack in the measurements was 5.6 and the clearance height Reynolds number ranged between 2000 and 102,000. The far-field sound was measured using a 64-microphone spiral phased array and the array output was beamformed to reveal the tip clearance noise sources. It is expected that the test rig will aid in a better understanding of the sound radiated by tip clearance flows which may be used to devise noise control strategies in the future.
The design, characterization, and performance assessment of an aeroacoustic measurement system for a hard-walled wind tunnel
Authors: Awasthi Manuj , Doolan Con , Croaker Paul
Published: November 2023

A new aeroacoustic measurement system for the large wind tunnel (LWT) at the University of New South Wales (UNSW) has been designed and characterized. The LWT is a closed-return type wind tunnel with a 2.87m × 1.28 m × 0.92 m hard-walled test-section, which contains 0.61m × 0.61 m access windows one of which was used to attach a 1.06m × 0.61 m × 0.61 m anechoic chamber lined with 100 mm thick Basotect foam. A 16-microphone spiral phased array embedded in the chamber was used to characterize the acoustical properties of the chamber and localize several acoustic and aeroacoustic sources placed in the reverberant test-section. Acoustic sources considered include single and dual speaker setup, while a UAV propeller and a forward-backward step mounted on the test-section sidewall were used as an aeroacoustic source. The beamforming output in each case was deconvolved using several existing algorithms to assess their performance under reflective boundary conditions. Additionally, a numerical tailored Greens function approach to beamforming is being considered to exclude the effects of reverberations within the test-section from the array output. It is expected that the present work will help develop strategies and guidelines for aero/hydroacoustic testing under reverberant conditions.
Bringing free weight areas under acoustic control
Authors: Brahman Max
Published: November 2023

Fitness studios that are housed in office, residential, or hotel buildings are repeatedly confronted with the problem that the strong vibrations caused by dropping weights lead to noise and vibrations in the entire building or even cause damage to existing ceiling structures. For these situations, Getzner has developed the g-fit Shock Absorb system with low construction heights and low weight. This is achieved through several layers of polyurethane foam materials including high damping or high elasticity sub-layer. The impact is isolated, the drop energy is absorbed by the material and dangerous rebound of the weights (dumbbell, barbell, kettlebells, etc.) is prevented. But the best flooring system can hardly be used without a proper prognosis of the isolation effect and the achieved sound pressure level in adjacent rooms. This paper is about the development of a prognosis tool that allows to predict the sound pressure level as a function of the impact energy, the type of weight at gym, and the ceiling mass for all g-fit Shock Absorb floor coverings. The extensive drop tests as well as the evaluation and the development of a prediction function is described in detail and explained by examples.