bluuebunny/crossref_metadata_2025 huggingface dataset:
A comparative analysis of Violin and Erhu: Examining the differences and similarities through statistical analysis of multiple musical excerpts
Authors: Song Wenyi , Huang Zeyu , Horner Andrew B.
Published: November 2023

Recent work has compared the different emotional characteristics between the violin and erhu on the Butterfly Lovers Concerto. In this study, we investigate whether the previous studies’ results hold generally in Chinese and Western classical music. Building upon previous research, we hypothesize that the violin conveys more positive emotions, while the erhu is perceived as sadder. We also expect the violin to be better at conveying high-arousal excerpts. To test these hypotheses, 46 subjects were presented with 14 excerpts, with each excerpt represented by at least four different performances of both instruments. For each performance, subjects were asked 4 binary questions: whether it was happy, sad, agitated, and calm. Results show that the erhu is consistently perceived as sadder than the violin, while the violin is perceived as happier, calmer, and more agitated when significant differences appear. Linear regression analysis suggests that instrument is a more significant factor in the emotional perception of low-arousal excerpts than high-arousal ones. Additionally, performance was a less important factor than instrument on affect perception, and made more of a difference on low-arousal than high arousal excerpts. Meaning, there was more variation between different performances of the same except on low-arousal excerpts than high-arousal excerpts.
Broadband noise absorption by time-varying devices
Authors: Han Xue , Hu Ying , Zhu Xiaocong , Huang Lixi
Published: November 2023

A resonator array can broaden the effective sound absorption bandwidth by using the structure with multiple cavities in parallel or in series in space. However, this kind of fixed mechanical structure cannot flexibly adapt to different noise sources, which severely limits the development prospect of the resonator array in practical applications. In this paper, a time-varying resonator is proposed based on a shunted electrical circuit, realizing the equivalent effect of multi-cavities in space. Based on the working principle of spatial and temporal resonators, the theoretical models are established, and the three designs for achieving broadband effects are analyzed theoretically. Through time-domain numerical calculation, the sound absorption performance of the two spatial designs and the temporal design with the same cavity volume is obtained. This study focuses on the scheme design and performance optimization of the temporal resonator. Compared with the traditional spatial resonator, the proposed temporal resonator has the advantages of tunable frequency and high adaptability to varying sources while achieving similar or even better sound absorption performance.
Approximation of the power distribution from multiple sound sources in the atmosphere using sums of gamma random variables
Authors: Kamrath Matthew J. , Krackow Max E. , Wilson D. Keith
Published: November 2023

A sum of gamma random variables is a mathematically tractable approach to approximate multiple sources when the power (amplitude squared) of a single source is nearly gamma distributed because the sum can be expressed analytically for a wide variety of cases. Previous work indicates that the gamma distribution is a good two-parameter empirical approximation of received power from a single, elevated sound source in a turbulent atmosphere. The gamma distribution can be conceptualized as a sum of k independent and identically distributed exponential random variables, each with mean m. Here, k and m are called the shape and scale parameters, respectively. Thus, the summation of multiple gamma random variables with the same scale parameter still yields a gamma distribution. When multiple sources can be approximated well using a gamma distribution, then those sources could be grouped together for simplicity and conceived as a single source in a turbulent atmosphere. In addition, multiple authors have derived analytic expressions for the sum of N independent gamma random variables with distinct parameters in terms of the confluent hypergeometric functions. If the gamma random variables are correlated, then the result is still analytic using recurrence relations.
Providing acoustical advice for the purpose of strategic land-use planning
Authors: Teyhan Katie
Published: November 2023

Strategic land-use planning is the process where stakeholders work together to design future land-use to achieve more desirable economic, social or environmental outcomes. There is often uncertainty around the type of acoustical advice required for the purpose of informing strategic land-use planning decisions. There are also limitations to the level of technical detail that can be made available when little is known about the nature or locations of potential future development. EMM Consulting Pty Limited’s experience in recent years has provided opportunities to work on various strategic land-use planning projects. This experience has enabled an understanding of what is required by relevant stakeholders to appropriately inform decisions as well as what is possible from a technical perspective. The importance of establishing clear expectations around technical outcomes and uncertainties is highlighted, as well as the importance of collaboration with all relevant stakeholders. A strong understanding of the planning framework the project will be approved and operate within is critical. The importance of having an appropriate authority and/or framework to facilitate the implementation of required noise measures and a plan to transition existing land use is discussed. The benefits and limitations of a Noise Management Precinct, as described in the Noise Policy for Industry (NSW EPA, 2017), are identified. Noise modeling methods and technical assumptions that could be utilized to predict and manage likely impacts are described.
Effects of the preference for acoustic stimuli on sleep quality
Authors: Maki Shota , Otsuka Sho , Nakagawa Seiji
Published: November 2023

Since pharmacological treatment for sleep disorders has a risk of addiction, developments of non-pharmacological tools to enhance sleep are needed. Colored noise sounds characterized by the power spectrum, e.g., white, pink, brown, blue, and purple noises, have been used in some non-pharmacological sleep aids. Former reports showed that white and pink noises were effective for sleep, however the mechanisms how such noises promote sleep remain unknown. In this study, we proposed a hypothesis that effects of colored noises are depending on participants' auditory impressions and examined how each participant's preference for the noises affected sleep-quality indices (sleep latency and duration of slow-wave sleep (SWS)). Sleep states of each participant were examined by EEG in three conditions: (i) the most preferred and (ii) the least preferred noises for each subject, and (iii) no stimulation. Sleep experiments were started at 3:00PM in a soundproof room and the stimulus began to be presented at lights-out and continued for 60 min. In results obtained, there were no significant differences in the sleep quality indices among the three conditions. Since duration of the experiment may not be enough to observe the effect of the stimuli, further investigations are needed after reviewing the experimental conditions.
Environmental noise predictions using a statistical approach
Authors: Wassermann John H. , Hall Nic
Published: November 2023

Noise pollution from industrial premises has the potential to have an impact on neighbouring properties. In New South Wales the Environment Protection Authority has developed the Noise Policy for Industry (NPfI). The NPfI requires noise assessments to be conducted using a typical assessment procedure that results in setting project noise trigger levels (PNTLs) which are the benchmark levels against which potential noise impacts from industrial developments are judged. The PNTLs are then used in Environmental Protection Licences to regulate the premises. The NPfI requires noise assessments to consider worst-case (i.e., noise-enhancing) meteorological conditions. In addition, regulators and consent authorities often require noise assessments to include a range of other conservative assumptions such as worst-case source levels and locations. This process appears to be very conservative, particularly considering that the PNTL in each assessment period (day, evening and night) are based on lowest 10th percentile background noise levels. This paper, through a statistical approach of using random probability distributions, will identify the likelihood that modelled noise levels and associated impacts are likely to occur and comment on the appropriateness of the conservative assessment process.
Bubbles as high-frequency rheometers for soft matter characterization
Authors: Lajoinie Guillaume , Oratis Alex , Rezaei Ali , Dijs Kay , Versluis Michel , Snoeijer Jacco
Published: November 2023

Precise knowledge of bubble dynamics in tissue is essential for optimizing both ultrasound imaging and ultrasound therapy. Great efforts have therefore been made, over the past decade, to model the behavior of (micro)bubbles in viscoelastic materials. This has led to a series of models based on modified Rayleigh–Plesset equations. Last to date, we propose a novel generalized model build on finite strain theory and relaxation functions. At this stage however, the bottle neck remains our limited knowledge of tissue viscoelasticity at high strain rates, which is a necessary input to any theoretical model. Indeed, traditional rheometers cannot reach frequencies above 1kHz, which is 3 orders of magnitude below the desired MHz frequencies. We will show how ultrasound-driven bubbles can be used as microscale rheometers. More specifically, we use the volumetric oscillations of (monodisperse) phospholipid-coated microbubbles embedded in hydrogels to measure the storage and loss moduli in the MHz frequency range. In addition, we can bridge the gap between kHz and MHz using the surface modes of cylindrical microbubbles trapped in micropits. These oscillations can be both modelled and simulated, and provide access to the effective surface tension and viscosity in the range of 50 to 500 kHz.
Numerical investigation of bubble pinch-off dynamics
Authors: Jacob Chinthaka , Manasseh Richard , Ooi Andrew , Nelli Filippo , Zhu Shaung Jie
Published: November 2023

While several mechanisms have been conjectured for the bubble pinching-off process, the underlying mechanism is still poorly understood, leaving the connection between the observed kinematics and the amplitude of the sound generated during the process unclear. Despite some experimental studies reporting the kinematics and the corresponding amplitude of the bubble sound emissions simultaneously (Nelli et al., AFMC, 2022), minimal numerical studies have been conducted to supplement these experiments. We report a numerical study by reproducing incompressible bubble pinch-off interface kinematics. Numerical simulations were performed by the volume-of-fluid (VoF) method, which keeps track of each phase fraction using a solution of the interface advection equation. Simulations are in good agreement on the kinematics at pinch-off despite several challenges associated with high-speed, high-distortion-rate interfacial dynamics.
Evaluation of photogrammetry-based near-field head related transfer function estimation for immersive sound reproduction
Authors: Hossain Shayikh , Sun Huiyuan , Jin Craig
Published: November 2023

Binaural reproduction algorithms are commonly applied in virtual and augmented reality applications to create immersive audio environments. Nonetheless, flexible near-field binaural rendering remains challenging. In this work, we explore the acoustic accuracy of photogrammetry-based, near-field head-related transfer function estimation. Photogrammetry measurements of the Head and Torso Simulator (HATS) are taken using a photogrammetry rig consisting of 44 synchronized Canon 1300D DSLR cameras mounted on ten aluminium poles arranged in a circle of 0.8m radius. An Apple iPhone 14 Pro mobile phone is used to acquire the ear data. Commercial photogrammetry software is then used to create a 3D mesh from the still images. Finally, numerical acoustic simulations using the fast multipole boundary element method (FM-BEM) technique are applied to the mesh to generate the near-field HRTFs. We present comparisons of acoustically-measured and photogrammetry-based near-field HRTFs.
An evaluation of various spatial audio rendering and presentation techniques to enhance active navigation with sensory augmentation
Authors: Nguyen Minh , Zhu Howe , Sun Huiyuan , Nguyen Vincent , Jin Craig , Lin Chin-Teng
Published: November 2023

Active navigation is essential in everyday life and refers to the combination of cognition (spatial mapping, path planning, and decision making) and motor-sensory execution (moving and sensing environment). For people who are blind or have low-vision, auditory and tactile sensory augmentation is critical to active navigation. In assistive technologies, binaural spatial audio rendering is widely adopted. However, the most effective methods to support fluent spatial navigation are still being studied. For example, in a previous study, we demonstrated the feasibility of using spatialized earcons to support a shorelining task. In this work, we use the same shorelining task to explore various forms of spatial earcon presentation with a focus on standardization and effectiveness. We also explore the development of an intuitive auditory grammar for spatial and contextual cues. We conduct psychophysical experiments and present experimental measures such as performance time and accuracy, heart-rate variability, and the NASA task load index.
Deep-subwavelength phononic beams with topological interface states
Authors: Park Seongmin , Jeon Wonju
Published: November 2023

We propose deep-subwavelength phononic beams that can support topological interface states (TISs) at low frequencies. To achieve this, we employ unit cells with acoustic black hole (ABH) configurations, enabling the creation of the first band gap in a low-frequency range where the unit cell size is much smaller than the wavelength of the controlled wave. Connecting two distinct beams with different topological properties results in TISs within their low band gaps. Through numerical simulations and experimental validation, we demonstrate the realization of TISs in the frequency range of 4.3–8.5 Hz, utilizing the designed phononic beams with lattice constants less than λ/20.
The integration of metamaterials into building elements
Authors: Hall Andrew , Sorokin Vladislav , Calius Emilio P. , Schmid Gian , Dodd George
Published: November 2023

The building industry continues to rely on homogeneous materials for acoustic insulation despite the progress of research into acoustic metamaterials. With the inevitable densification of housing, the severity of noise pollution within residential living environments is escalating. While the insulation of high-frequency audible sound through building elements is often relatively good between 1 and 5 kHz, the overall acoustic transmission loss performance is often significantly limited by two specific frequency regions. The mass air mass resonance band, and the coincidence band. We present the results of an investigation into the use of metastructures and metasurfaces to improve transmission loss in these frequency regions with a focus on scalable implementation. These metastructures are metamaterial systems constructed from impedance change elements, surface variations and vibroacoustic resonant elements. The performance of selected systems from this research are presented. Experimental and modeling results are in good qualitative agreement and promising diffuse-field testing results indicate significant attenuation within the targeted band regions. The merits of each technique are analysed, and results indicate which methods are most effective at either mitigating or shifting the regions of poor transmission loss outside of the most important part of the audible frequency region.
Analysis on sound absorption in Sonic Black Holes
Authors: Zhang Xiaoqi , He Nianwen , Cheng Li , Yu Xiang , ZHANG Linke
Published: November 2023

Exploration of Acoustic black holes (ABHs) for sound wave manipulation is referred to as Sonic black holes (SBHs). Different from the ideal SBH structure with continuously varied wave propagation boundary formed by putting extensive number of rings inside, the wave trapping and energy dissipation mechanism of practically realized SBH structure with discrete varied wave propagation boundary formed by quite limited number of rings inside are still not clear. To fill the gap, finite element simulations are performed to assess the sound absorption performance of a practical discrete SBH structure and explore the sound absorption mechanism behind. The validity of the FEM results is demonstrated through comparisons with experimental data obtained through impedance tube tests. Analyses reveal that the physical mechanism underpinning the sound absorption of practically realized SBH device is attributed to the combined effects of the ABH-induced wave speed changes, energy trapping and the spatially graded local resonances of series cavities formed by the space between two adjacent rings. While shedding light on the underlying sound attenuation mechanism, studies provide guidelines for further investigations on SBH structures.
The acoustic metasphere. A solution to improving speech intelligibility and acoustic measurements
Authors: Hernandez Gregory , Li Junfei , Cummer Steven
Published: November 2023

The application of acoustic metamaterials has found utility in several disciplines ranging from biomedical ultrasound to architectural acoustics, and even the music industry. However, an underlying complication with these devices is their narrow bandwidth which limits the effectiveness of acoustic metamaterials in research and industry. Additionally, within architectural acoustics and noise control engineering, an issue that arises is speech intelligibility and clarity of the source. For example, within a populated and dense environment, such as an airport or shopping market, loudspeakers are placed every several feet to surmount the beaming directionality of these transducers at higher frequencies. Also, consequently, the gain must then be high enough to overcome this beaming effect and the noise floor generated by the environment and its occupants. Moreover, methods to more efficiently and cost effectively characterize the response of an acoustic space are needed to improve upon the noise control efforts within these locations. A solution to these obstacles is proposed with an acoustic metamaterial called the Acoustic Metasphere. Utilizing various twisting unit cells that fully envelop a loudspeaker, we demonstrate here that this acoustic metamaterial can improve the limitation of a loudspeaker due to its directionality, while simultaneously increasing the bandwidth of operation for this engineered structure.
On the nature of Tone 4 alternation in Taiwan Mandarin: Insights from acoustic analysis of trisyllabic right-branching word productions
Authors: Liu Chin-Ting
Published: November 2023

Tone 4 (T4) alternations refer to the phenomenon where the tone values of a T4 syllable reduces from ‘51' to ‘53' when it is followed by another T4 syllable in Mandarin Chinese. It is inconclusive if the nature of T4 alternations is tone sandhi (an abstract phonological rule) (Chao, 1948; Jang, 2021) or tonal coarticulation (an articulatory phenomenon in speech production) (Lin, 20007; Shen, 1990). The current study invited 30 Taiwan Mandarin speakers to produce 10 pairs of right-branching trisyllabic words, including sequences of [T4[T4-T4]] (e.g., dà diàn shì 'big television') and [T4[T4-Tone1]] syllables (e.g., dà diàn jiā ‘big store'). The T4 sandhi view predicted that the surface tone values of the first syllables in these two sequences would differ (“51i” vs. “53”), while the T4 coarticulation view predicted that the tone values would be the same (“53”). Results from the acoustic analysis on fundamental frequency (f0) contour, f0 slope and vowel length of the first T4 syllables indicated that the differences were not statistically significant. These results supported the tonal coarticulation view. Discussions pertaining to the mental grammar for the tone value distances of two adjacent T4 syllables and the typology of tonal coarticulation in Mandarin Chinese are formulated.
Making figure models of speech articulators for speech production research
Authors: Hirayama Makoto J.
Published: November 2023

Physical 3D figure models of speech articulators including tongue, lips, upper and lower jaws with teeth, were made with regin and gel materials, for research and educational purposes of speech production mechanisms. Regin models were made using a 3D printer and gel models were made with hand crafted cray and a molding method. The models focuses on physiological organs and muscles inside a mouth to understand coordinated speech articulator motions driven by multiple muscles of musculoskeletal systems. For upper and lower jaws, and a hyoid bone, 3D models are designed using computer graphics software and transferred to a 3D printer to make regin models. For tongue and tissues inside mouth, cray was used to make handcrafted original model and molding was done using viscoelastic urethane gels to be duplicated. Intrinsic and extrinsic tongue muscles were modeled as one figure model, but some extrinsic muscles connected outside a tongue body were modeled individually. The models are used to teach speech production mechanisms in a university class. By using physical models, they are contributed to understand complex speech articulation mechanisms inside a mouth, more intuitively and easily.
Synthesizing medical terms—Quality and naturalness of the deep Text-to-Speech algorithm
Authors: Kostek Bozena , Szyca Barbara
Published: November 2023

The main purpose of this study is to develop a deep text-to-speech (TTS) algorithm designated for an embedded system device. First, a critical literature review of state-of-the-art speech synthesis deep models is provided. The algorithm implementation covers both hardware and algorithmic solutions. The algorithm is designed for use with the Raspberry Pi 4 board. 80 synthesized sentences were prepared based on medical and everyday language employing the TTS algorithm developed. For tests, an application is built, containing a questionnaire allowing for evaluating the quality and naturalness of the synthesized speech, for both types of language. It is followed by the algorithm efficiency tests. A presentation of the performed tests, along with the results obtained from 30 respondents, is shown. The discussion consists of a statistical analysis of the obtained results and a comparison with other speech recognition solutions used as a reference. Finally, in the summary section, there is an overall conclusion of this approach and promising directions for future development. [This work is supported by the Polish National Center for Research and Development (NCBR) project: “ADMEDVOICE-Adaptive intelligent speech processing system of medical personnel with the structuring of test results and support of therapeutic process,” no. INFOSTRATEG4/0003/2022.]
Efficient measurement of spoken English skills: Design and validation of a 6-minute assessment
Authors: Bernstein Jared C. , Cheng Jian , Suzuki Masanori
Published: November 2023

Efficient measurement of spoken language skills can improve educational and commercial services. Traditional spoken language assessments often require 30–90 minutes. We report the development and validation of a prototype mobile-browser test of spoken English, “APro”, that participants complete in 6–8 minutes. The APro test presents a stratified random draw of 20 interactive tasks (from pool of 377) to participants whose spoken responses are automatically scored, scaled, and reported. APro aggregates skill-specific measures from disparate task types such as open descriptions and story retellings. Each skill-specific score was independently validated, then combined into an overall spoken English score. APro scoring was trained on 30,000 responses from 354 non-native pilot-test participants who connected remotely from their nine home countries on five continents. The final APro instrument was validated on an independent sample of 79 participants resident in seven countries. In the validation set, human and machine scoring of same-test APro administrations correlated r = 0.98, suggesting accurate speech processing. APro scores predicted much of the score variance in traditional concurrent assessments from Oxford, r = 0.86, and Pearson, r = 0.92. Finally, we present detailed results on two new interactive tasks and share changes to the content, procedure, and scoring that yield improved accuracy at shorter duration. [Work supported in part by Google LLC.]
Neural network-based measure of consonant Lenition in Parkinson's disease
Authors: Wayland Ratree , Tang Kevin , Wang Fenqi , Vellozzi Sophia , Meyer Rachel , Sengupta Rahul
Published: November 2023

This study investigates the effects of Parkinson's disease (PD) and various linguistic factors on the degree of lenition in Spanish stops. The lenition is estimated from posterior probabilities calculated by recurrent neural networks trained to recognize sonorant and continuant phonological features. First, individuals with PD exhibit a higher degree of lenition in their stops compared to healthy controls, suggesting that PD has a significant impact on the articulatory control of stops, resulting in more pronounced lenition. Second, stress influences the degree of lenition, with stressed syllables showing less weakening compared to unstressed syllables. Thirdly, place of articulation plays a role in lenition, but the effects differ between PD and healthy control groups. PD patients demonstrate greater weakening in bilabial and velar stops compared to dental stops, while healthy controls exhibit more lenition in velar stops, with no significant difference between bilabial and dental stops. These findings suggest abnormalities in lip movement control among PD patients align with previous research on reduced lip velocities in Parkinsonian patients. Importantly, the study highlights the effectiveness of recurrent neural networks in quantifying lenition in PD patients.
Multizone reproduction by matching the velocity vectors
Authors: Wang Jiarui , Abhayapala Thushara , Zhang Jihui (Aimee) , Samarasinghe Prasanga N.
Published: November 2023

This paper proposes a velocity-based multizone reproduction method, which reproduces the velocity vectors throughout each listening zone. Velocity vectors are related to the localization of sound below 700 Hz. Previous work considered reproducing the velocity vectors at sweet spots or on the listening zone’s boundary, and usually involved measurements using multiple velocity sensors. In this paper, in each listening zone, the velocity vectors are calculated from the spherical harmonic coefficients of the pressure, which are obtained by a spherical microphone array. The calculation of the velocity vectors is based on the sound field translation formula. Moreover, by reproducing the desired velocity vectors throughout each listening zone, listener's movement within each zone is allowed. To enlarge the size of the listening zone, the sound field in each listening zone is expressed by a sparse distribution of plane waves that results in the same velocity vectors. The pressure transfer functions between each loudspeaker and each listening zone are measured by placing a spherical microphone array at multiple spatial sampling points within each listening zone. The loudspeaker driving functions are calculated by matching the velocity vectors due to the sparse distribution of plane waves in each listening zone.
Consistent physical frequencies in time-frequency analysis
Authors: Guers Manton J.
Published: November 2023

Wavelet transforms have been studied extensively for a wide variety of applications such as signal compression and signal denoising. Wavelet transforms have also been examined for the detection of transient signals. However, wavelet levels (and corresponding pseudo-frequencies) are inherently dependent on the sampling rate of the analyzed data. The work presented herein examines how wavelet analysis can produce inconsistent data representations for the same analytical signal digitized at different sampling rates. Results are compared to time-octave and other time-frequency representations to identify methodologies which produce consistent characterization of physical frequencies. Similarities and difference between approaches are discussed.
Shift-variant deconvolution beamforming using Implicit Neural Representation for near-field acoustic image measurement
Authors: Zhou Yifan , Fang Shiliang , An Liang , Chen Lijun
Published: November 2023

The conventional beamforming (CBF) output can be expressed as a convolution of the source distribution and the array dependent point spread function (PSF), which is defined as the response of the beamformer to a point source. The resolution and accuracy of sound source localization can be improved by deconvolution of CBF. The shift-invariant PSF assumption is only a good approximation when the source region is small compared to the distance between the array and the source. However, the PSF of the near-field underwater acoustic map measurement is shift-variant, whose mismatch with the beam could lead to performance degradation. In this paper, we proposed an optimized deconvolution method by using the neural network called implicit neural representation (INR) to solve the beam mismatch problem, due to its strong performance in learning and reconstructing spatial scenes. Rather than recompute the PSF for each pixel in the scene, INR predicts the complex-valued weight matrix in two-dimensional space that encapsulates both the spatially varying properties of the PSF and the scatter distribution of the scene. Numerical simulations and experimental results verify the effectiveness of our method. And this work can be broadly applied to arrays with shift-variant PSFs.
An overview of the MASTODON sonar simulator
Authors: Woods Denton
Published: November 2023

The Modular Acoustic Simulation Toolset of the Department of the Navy (MASTODON) is a feature-rich ray-based sonar simulator derived from the Personal Computer Shallow Water Acoustic Toolset (PC SWAT) codebase, developed at the Naval Surface Warfare Center Panama City Division over several decades. This paper discusses the design of this new simulation architecture and gives an overview of its features and models used. New simulation capabilities will be highlighted that enable drastic speed improvements from the addition of graphics processing unit (GPU) simulation code into MASTODON’s codebase. [Work supported by the Office of Naval Research.]
Evolution of the highest sound pressure levels in mammalian echolocation calls
Authors: Walker Benjamin J. , Jordan Neil R. , Rogers Tracey L.
Published: November 2023

Recent work has shown that for some echolocating bat species there is a physical limit to the loudness of their echolocation signals, and this idea has been extended to suggest there is a physical limit to the loudness of echolocation signals of all species. This is at odds with the assumption that the loudness of a species call is driven by their body size, where louder species are larger species. This is also at odds with the prey detection hypothesis, where for echolocation calls the successful detection of prey at size extremes (both minima and maxima) drives the loudness of echolocation calls. A physical limit of loudness in echolocation calls may exist, but this has not been explored using comparative analysis. We compare the loudest echolocation calls across 63 echolocating mammals (including almost half of all aquatic echolocators) and show the assertion of a physical limit to loudness exists for bats in terrestrial habitats but breaks down for odontocetes in aquatic habitats. For aquatic echolocators, the loudness of their echolocation calls scales with body mass. We examine evolutionary and ecological pressures which may have led to these differences, and their influence on echolocation loudness.
Energy partitioning of the underwater soundscape
Authors: Barclay David R. , Shajahan Najeem
Published: November 2023

A four-element three-dimensional hydrophone array has been deployed on the Strait of Georgia node of the Victoria Experimental Network Under the Sea (VENUS) since March 2020. To the present, continuous pressure time series data from the four sensors has been streamed ashore and made available by Ocean Networks Canada. A technique for classifying and partitioning ambient noise using the three-dimensional noise coherence function is applied to the recordings. The noise coherence (directionality) due to wind generated surface noise and individual ships is analytically modelled using measured environmental inputs such as the time varying sound speed profile and sediment properties from the measurement site and compared with the observation. The theoretical coherence curve is computed by mixing the contributing sources until a best-fit is found. Since the wind generated surface noise coherence is stable and independent of the source effective sound power per unit area, the contribution of ship noise to the soundscape can be exactly determined. Applying this algorithm to the long-term data set allows the relative contribution of ship noise to the soundscape in the region to summarized succinctly. [Research supported by ONR.]
Underwater noise from submarine turbidity currents
Authors: Hay Alex E. , Hatcher Matthew , Hughes Clarke John E.
Published: November 2023

Submarine landslides and associated turbidity currents can be orders of magnitude larger than their terrestrial equivalents. Their prevalence globally is hugely underrepresented by in situ observations. In addition to their importance in mass transport and morphologic change they can pose significant threat to coastal communities and subsea infrastructure. This presentation focusses on noise measurements from turbidity currents flowing down the face of a fjord delta and how they can inform the use of passive acoustics as a tool for future observations of these under sampled phenomena. Noise was measured underwater at frequencies from 1 to 1200 kHz. The noise spectra are consistent with sound generation by collisions among sand-sized particles within the turbidity current, also known as acoustic sediment-generated noise or SGN. The spectra from the leading head of the current extend to higher frequencies than those from the trailing body, indicating that collisions were between finer-grained particles in the head and coarser-grained particles in the body. Noise intensity increased 100-fold for a two-fold increase in current head speed, consistent with the expected collision rate for granular materials in the high-flow gas-like phase and highly turbulent particle-laden flows.
Single and multiple scattering quantitative ultrasound methods in the lung
Authors: Dashti Azadeh , Roshankhah Roshan , Muller Marie , Mamou Jonathan
Published: November 2023

Lung ultrasound images are qualitative and rely on subjective interpretation for diagnosis. Ideally, quantitative ultrasound (QUS) methods applied to lung ultrasound data would provide biomarkers associated with specific diseases in an absolute fashion. While QUS methods are successful in numerous organ systems in preclinical and clinical applications, their direct application to lung ultrasound data requires taking multiple scattering (MS) into account. This presentation shows QUS methods independently exploiting MS and single scattering (SS) components of radio-frequency (RF) data, acquired from lungs from rodent models of pulmonary edema and fibrosis. SS and MS components were obtained using singular value decomposition and eigenvalue thresholding. Spectral and envelope QUS parameters were computed from the SS component. MS-based QUS parameters were obtained by extracting the diffusion constant and tracking the SS intensity decay rate. Stepwise linear discriminant analyses using only three QUS parameters yielded strong correlations between wet-to-dry ratio in healthy and pulmonary edema rats. Strong correlations were also obtained between QUS parameters and modified histological Ashcroft scores in healthy and pulmonary fibrosis rats. These results demonstrate the value of QUS parameters obtained from SS and MS approaches for assessing lung diseases with high specificity and sensitivity. [Supported in part by R21HL154156 and W81XWH1810101.]
Machine learning based flexible piezoelectric sensor
Authors: Lee Keon Ja E.
Published: November 2023

This seminar introduces flexible inorganic piezoelectric membrane that can detect the minute vibration of membrane for self-powered acoustic sensor and blood pressure monitor. Herein, we reported a machine learning-based acoustic sensor by mimicking the basilar membrane of human cochlear. Highly sensitive self-powered flexible piezoelectric acoustic sensor with a multi-resonant frequency band was employed for voice recognition. Convolutional Neural Network (CNN) were utilized for speaker recognition, resulted in a 97.5% speaker recognition rate with the 75% reduction of error rate compared to that of the reference MEMS microphone.
A high-fidelity MEMS microphone with a polymer membrane that can detect infra-sounds
Authors: Kim Junsoo , Kim Woongji , Lee Siyoung , Cho Kilwon , Moon Wonkyu
Published: November 2023

This study proposes a polymer MEMS microphone that operates through electromechanical amplitude modulation. We have developed a highly optimized MEMS structure with a flexible polymer material, resulting in a miniaturized and flexible device with excellent acoustic performance. The stiffness and damping characteristics of the polymer diaphragm are analyzed and it shows that the polymer material would be suitable for microphone applications. An equivalent circuit model is also developed for design purposes, so that the device could be properly designed using it and fabricated by in-house polymer thin film processes. The fabricated device is tested using a DC bias scheme to reach its signal-to-noise ratio (SNR) of 65 dBA within a bandwidth of 10 to 10,000 Hz, which is comparable to existing high-end commercial silicon MEMS microphones. We would then extend the frequency bands of linear detection down to the infrasound range by using electromechanical amplitude modulation. This operation scheme can also provide the microphone with no need for metal packaging. Its feasibility is confirmed theoretically by numerical simulations including electromechanical amplitude modulation and experimentally by implementing it at the PCB level. In addition, this approach enables the sensor stronger to the environmental noise so that metal shielding could be omitted.
Application of soundscape methodologies in an acoustic consulting context
Authors: Gleeson Sophie , Allen Mitchell J.
Published: November 2023

Understanding environmental sound from subjective perspectives is important for comprehending sound qualities beyond physical parameters. Soundscape approaches are promoted as valuable frameworks for understanding subjective experiences of environmental sound. However, the application of such approaches in acoustic consulting environments is limited and the demonstrated value is unclear. This study investigates the applicability of soundscape methodologies in a corporate consulting context. In this paper we summarise available soundscape methodologies and their known challenges, and test the application of select methods, including sound mapping and soundscape descriptors, in different acoustic consulting settings at Arup. Through practical application, we explore the contexts in which soundscape approaches may be used to document, assess and describe sound environments. We review barriers and limitations experienced through application, such as training, project constraints and the need for project-specific methodology adaptation, and discuss values that emerged, including an enriched understanding of sound qualities not otherwise captured through conventional acoustic approaches. We position this research as a step towards developing a soundscape toolkit for acoustic consultants and argue that the incorporation of a soundscape perspective in acoustic consulting is necessary to expand the ways in which we understand environmental sound and its effects on those within it.
The soundscape method and eco-acoustic indicators in the analysis of the acoustic environment of the mountain national parks in Poland and Sweden
Authors: Mlynarczyk Dorota , Wiciak Jerzy
Published: November 2023

Soundscape is one of the essential environmental elements affecting people’s experience in nature spaces. In the complex mechanism of landscape and soundscape perception, the acoustic characteristics of the environment are the primary influencing factor. The aim of the paper is the analysis of soundscape of two mountain national parks—Tatra National Park (TNP) in Poland and Sarek National Park (SNP) in Sweden. The first park is very frequently visited by tourists (around 4 million tourists a year) while the second park has an attendance of around a few thousand tourists. The paper presents the results of the analysis of acoustic measurements and ambisonic recordings made in the Koscieliska Valley (TNP) and the Rapa Valey (SNP, Swedish: Rapadalen) using classical method and the soundscape method. In addition, psychoacoustic parameters and soundecology indicators such as loudness, sharpness or roughness, ACI (acoustic complexity index), NDSI (normalized difference soundscape index), BIO (bioacoustic index), ADI (acoustic diversity index), and AEI (acoustic evenness index) were calculated.
Noise measurement, litigation, positioning and acoustic remediation of a heat pump installed at INAIL headquarters in the city of Salerno (ITA)
Authors: papa augusto , Mariconte Raffaele
Published: November 2023

The study concerns a particular case of an air conditioning system subject to a legal dispute with the residents of the building of the INAIL headquarters in the city of Salerno. The system moved from the terrace to the ground, involved a complex forecast assessment of acoustic impact with subsequent adequate acoustic remediation.
A wide field-of-hearing metalens for aberration-free sound capture
Authors: Lee Dongwoo , Oh Beomseok , Rho Junsuk
Published: November 2023

Metalenses, as a designer tool for manipulating waves, has demonstrated remarkable capabilities thus far. However, their performance is limited to normal incidence and they exhibit significant sensitivity to oblique incidence. This sensitivity often leads to a decrease in focusing efficiency due to coma aberration, posing a considerable challenge. Here, we present a novel solution in the form of a wide field-of-hearing (FOH) metalens, specifically designed for capturing and focusing sound without aberration. To overcome the limitations of conventional metalenses, we propose a hybridized metalens that combines Helmholtz and zigzag building blocks. By incorporating both complete phase modulation and unitary transmission, this hybrid metalens achieves superior performance. We conduct experimental validations to demonstrate the proof-of-concept sound reception, thereby introducing the concept of wide FOH monitoring systems. The rational design of this metalens holds great versatility and can be implemented across various platforms. Its applications potentially span diverse fields such as energy harvesting, monitoring, sensing, imaging, and communication in auditory and submerged environments.
Binaural renderers accuracy comparison
Authors: LaFountaine Lisa , Plasse Raymond , Bulla Wesley
Published: November 2023

This study explored the ability of binaural renderers to accurately reproduce the placement of objects within a three-dimensional soundscape. Previous works have only tested localization on the horizontal plane; whereas, this research expanded on prior methodology by adding vertical targets along the medial and sagittal planes. Two commercially available binaural renderers were compared. Subject task was to map from where they heard the localization percept onto a planar response sheet. Results were consistent with previous horizontal plane research. However, renderer performances in the medial and sagittal domains were considerably less accurate than the horizontal plane. Findings here suggest more work is needed to ensure greater accuracy of localization cues provided by the binaural rendering process.
Investigating the effect of cochleotopic region on temporal processing using binaural fusion
Authors: BK Prajna , Aronoff Justin , Soleimanifar Simin
Published: November 2023

Processing of temporal information in a signal may vary across apical, mid and basal regions of the cochlea—there is evidence for this in both cochlear-implant and typical-hearing listeners. This effect may also be task dependent and has not been studied with respect to binaural fusion. Fusion depends on tracking the temporal fluctuations across ears which can be manipulated by varying the interaural correlation (IC) of a signal. To investigate the effect of place of stimulation on fusion, 9 bilateral cochlear implant users were presented with 1000 Hz pulse trains with varying envelope IC. An apical, mid, and basal electrode were separately selected as reference, each of which was then paired with five electrodes in the contralateral ear, spread across the array. Listeners indicated the spatial diffuseness and the number of auditory “images” of the perceived sound by manipulating a visual representation of their perception superimposed on a picture of a head. Preliminary results indicate that, for optimally paired electrodes, fusion increases similarly for the three regions of the cochlea with increasing IC, and when IC is 1, the degree of fusion is comparable across regions. Processing of temporal information for binaural fusion is not significantly different across cochleotopic regions.
Does sensitivity to interaural correlation changes correlate with binaural fusion performance?
Authors: B. K. Prajna , Soleimanifar Simin , Bernstein Leslie , Aronoff Justin
Published: November 2023

The purpose of this study was to assess whether and to what degree sensitivity to changes in interaural correlation (IC) in bilateral cochlear implant (CI) listeners is related to the overall degree of binaural fusion those listeners experience. Compared to typical-hearing listeners, CI users often report perceiving a reduced degree of binaural fusion. Because IC is a strong determiner of perceived fusion, degraded perception of fusion might be coupled with a relative insensitivity to changes in IC. To investigate this, two experiments were conducted. First, discrimination of IC changes was measured using the method of constant stimuli in which CI listeners identified the “target” interval containing an IC differing from the “reference” values of either 0.7 or 1.0. Stimuli were generated by modulating 1-kHz pulse trains by speech-derived envelopes the IC of which were manipulated. The same stimuli were used in a second procedure in which the perceived degree of fusion was quantified for ICs varying between 0.4–1.0. Preliminary results from both studies suggest that relative insensitivity to changes in IC are associated with a lesser degree of perceived fusion, overall.