bluuebunny/crossref_metadata_2025 huggingface dataset:
Towards the environmental noise assessment of Unmanned Aircraft Systems operations
Authors: Torija Martinez Antonio J. , Ramos Romero Carlos , Green Nathan , Hughes Richard
Published: April 2023

The rapid expansion of the Unmanned Aircraft Systems (UAS) sector poses a significant challenge for acoustic engineers working on the environmental noise impact assessment of these new aerial technologies. As widely recognised, the noise signatures and operational profiles of UAS differ significantly from conventional aircraft, and therefore, existing measurement procedures and assessment methods might not be able to provide an appropriate assessment of UAS noise. There are specific questions that should be addressed for a wider deployment of UAS operations without compromising communities’ health and well-being due to noise exposure: (i) how will communities respond to the unconventional noise signatures of UAS? and (ii) what measurement procedures and metric can ensure an accurate assessment of UAS noise impact? This publication describes the work carried out for the measurement and development of acoustic hemispheres for UAS operations containing sound level, frequency, and directivity information; and how this acoustic data can be used for noise mapping and auralization. Furthermore, a review of the state-of-the-art of noise metrics for UAS is presented, with a focus on existing gaps and further work required.
Attention to rattles and a non-equal-energy model are required for proper sonic boom assessment
Authors: Schomer Paul
Published: April 2023

This paper is concerned with the assessment of community response to sonic booms or blasts. It summarizes and analyzes the totality of results from studies in the English language that used real booms or blasts, with subjects in real buildings. In acoustics, we are accustomed to noise sources operating in accordance with the equal-energy principle (a 1 dB increase in amplitude is equivalent to a 1 dB increase in duration). The results show that rattles are the most important attribute contributing to the annoyance engendered by sonic booms/blasts, and that the process is not equal-energy. Rather, the equivalent annoyance generated by a change of 1 dB in the C-weighted boom or blast amplitude is equal to about a 1.5 to 2 dB change in the boom or blast duration where the exchange rate is defined to be 1 over these changes in duration, 0.67 and 0.5, respectively. The exchange rates found in several sonic boom/blast noise studies are given, and as an example, the exchange rate for the historical Oklahoma City study is calculated. The conclusions from the Long-Term Sonic Boom Noise Environments study are examined in relation to the range of exchange rates found in other boom/blast studies.
Particle image velocimetry of supersonic jets with micro vortex generators
Authors: Saleem Mohammad , Rodriguez Omar L. , Karnam Aatresh , Gutmark Ephraim , Liu Junhui
Published: April 2023

The flow field of supersonic jets with micro vortex generators (MVGs) is investigated using Particle Image Velocimetry (PIV) to shed light on the noise reduction mechanisms associated with such devices. Recently, MVG nozzles have been developed as a new noise reduction technology through the collaboration between the University of Cincinnati and the Naval Research Laboratory. MVGs were implemented on model scale nozzles representative of GE F404 engine nozzles, and noise reductions up to −6 dB have been observed in both microphone measurements and LES simulations. The PIV measurements of the flow field reveal that the MVGs alter the shock cell spacing and strengths in the jet plume and substantially reduce the mean axial velocity at the jet axis. In addition, streamwise vortices generated by MVGs enhance shear layer mixing and redistributes turbulence along the shear layer to narrower regions. The measured flow field quantities are extracted to explain flow field changes on the noise reductions observed in the acoustic far field.
Noise exposure of spectators at Utah air show
Authors: Lawrence David C. , Gee Kent L. , Moats Levi T.
Published: April 2023

Spectators are exposed to a variety of loud noises at air shows, which can contribute to noise-induced hearing loss. A previous study [Pääkkönen et al., Appl. Acoust. 64, 121–127 (2003)] on three Finnish air shows concluded that their air shows did not seem to exceed damage risk levels. This study investigated noise that spectators are exposed to at the Warriors Over the Wasatch Air and Space show at Hill Air Force Base. Noise dosage, exposure times, and LAeq for various aircraft were analyzed. The LAeq ranged from 75 to 95 dBA and the total noise dosage for the airshow was 118 %, exceeding the NIOSH recommended exposure limits with most of the noise coming from the fighter jets. This shows that spectators should use hearing protection if they plan to stay for the entire air show or at least during portions of an air show that contain fighter jets.
Development of gulfstream acoustics simulator
Authors: Wang Tongan
Published: April 2023

An acoustic simulator has been developed at Gulfstream Aerospace Corp. to evaluate aircraft interior acoustic environments. Many acoustic simulators developed in the past were based on headphones, but they could not be used to evaluate communication between passengers. Ambisonics and wavefield synthesis are popular methods to recreate sound fields in a 3D space, but they are either limited in the size of the recreated sound field or require great number of speakers. Therefore, a modal-based approach was used to recreate the sound field inside the Gulfstream acoustics simulator. This paper will discuss the construction of the simulator mockup, the analysis to determine the speaker placement, the test to measure the acoustic environment, and the hardware and software systems to control the simulator playback. The acoustic simulator will be used to demonstrate the acoustic environment on different aircraft in different flight conditions, evaluate the effect of improvement options, and develop advanced technologies to create finest aviation experience.
Sound transmission through raised access floors
Authors: Lemert Bryce , Salt Eric
Published: April 2023

Raised access flooring systems have become an increasingly popular option across the construction industry, but especially in the office environment. These systems allow for a modular design where electrical conduit and data cables can be easily accessed, and the underfloor air supply can eliminate the need for overhead mechanical systems. While the design has many benefits, the sound transmission through the plenum is a concern as the system introduces an additional flanking path to adjacent rooms. A variety of underfloor baffle options exist to help reduce the transmission through the plenum, each with their own challenges. There is currently limited understanding of the effect of sound transmission through the raised access plenum between adjacent rooms. This paper provides an introduction to the acoustics surrounding the raised access flooring system based on experiences and lessons learned in an as-built environment, both in terms of airborne and structure borne sound transmission. In particular, this paper examines the flanking path that is introduced through the plenum under walls constructed above the raised floor and the effect of underfloor baffles on this sound transmission.
The sound of the ingenuity Helicopter on Mars
Authors: Lorenz Ralph , Maurice Sylvestre , Chide Baptiste
Published: April 2023

The sounds of the Ingenuity Helicopter flying in the Martian atmosphere are among the most notable recordings of the microphone on the SuperCam instrument on the Mars 2020 Perseverance Rover. Distinct acoustic signatures of the helicopter were recorded on the 4th, 5th, 6th, and 8th flights. The detected signatures are around 84 Hz and (occasionally) at 168 Hz, at the blade crossing frequency and its first harmonic. Several higher harmonics were prominent in hover tests in short-range recordings in a test chamber on Earth; these are attenuated by CO2 absorption at the 50 m-plus ranges on Mars. Doppler shift of the 84 Hz signal can be measured and is consistent with the trajectory measured with Ingenuity’s navigation camera and inertial navigation unit, and documented by Perseverance’s cameras. A striking feature of the sound recordings is an unanticipated deep modulation of the signals with nulls spaced by around 15–20 s, superposed on the simple and expected decline in amplitude with distance. We have evaluated and rejected models of multipath sound interference as requiring implausibly strong near-surface temperature gradients. We find instead that the modulation appears to be the signature of a slight asynchrony between the rotation rates of the two coaxial rotors, such that the blade-crossing azimuth rotates slowly during flight, resulting in a “lighthouse” sweeping of the radiated sound pattern. Analysis of blade orientations seen in the shadow of the helicopter observed in down-looking navigation images supports this model.
Martian Wind and turbulence heard by the SuperCam microphone on the perseverance rover
Authors: Stott Alexander , Murdoch Naomi , Gillier Martin , Banfield Don , Bertrand Tanguy , Chide Baptiste , De la Torre Juarez Manuel , Hueso Ricardo , Lorenz Ralph , Martinez German , Munguira Asier , Mora Sotomayor Luis , Navarro Sara , Newman Claire , Pilleri Paolo , Pla-Garcia Jorge , Randazzo Nicolas , Rodriguez Manfredi Jose Antonio , Sanchez-Lavega Agustin , Smith Michael , Viudez Moreiras Daniel , Williams Nathan , Maurice Sylvestre , Wiens Roger , Mimoun David
Published: April 2023

On top of listening to laser shots, rover sounds and the Ingenuity rotorcraft, SuperCam’s Mars microphone has recorded over 7 hours of ambient background noise on Mars. These background recordings contain signal due to the Martian wind. Through a comparison to the meteorological data recorded by the MEDA (Mars Environmental Dynamics Analyzer), we can determine the relationships between the microphone data, the wind and the atmospheric stability. Based on these relationships, we have determined a way to estimate the wind speed using the microphone through Gaussian process regression, a machine learning technique. Owing to the sampling rate of 25 000 samples per second, the microphone data can be used to examine Mars’ atmospheric dynamics at high frequencies, as yet unexplored on Mars. We will demonstrate how the wind speed estimates from the microphone provide an assessment of turbulence at fine scales, shedding light on the dissipative regime on Mars. One particularly interesting signal recorded by the microphone was a dust devil, which had fast varying winds within the walls of its vortex and signal from dust particles hitting the rover. Combining the microphone data with information from the MEDA sensors and navigation camera (Navcam) images enabled a full parameterization of this event.
Acoustic recording of near-surface turbulence on Mars
Authors: Maurice Sylvestre , Blanc-Benon Philippe , Chide Baptiste , Bertrand Tanguy , Murdoch Naomi , Lorenz Ralph , Jacob Xavier , Dragna Didier , Stott Alexander , Gillier Martin , De la Torre Juarez Manuel , Rodriguez Manfredi Jose Antonio , Mimoun David , Wiens Roger
Published: April 2023

To study Mars chemistry, SuperCam onboard the NASA Perseverance rover fires bursts of 30 laser shots at rocks. Its microphone records the shock wave generated between 2 and 15 kHz by each laser-induced plasma for distances between 2 m and 8 m, at varying local times, from strong thermal turbulence during daytime, to weaker one at dusk or dawn. In each case, the scintillation index (the normalized variance of the intensity), and travel time are calculated. Based on extensive literature on the propagation of a spherical wave through a turbulent medium, there are enough statistics to constrain the field that causes the dispersion of acoustic data. Initial results show that data are well modeled by a Gaussian field. A negative time shift, ∼0.5% at 6 m, is observed: the resulting velocity is higher than the mean speed of sound (fast path effect). The variance of arrival times leads to a 15 cm characteristic scale during daytime. Fluctuations of the scintillation index allow the strength of the turbulence field to constrained. Other turbulence models are tested, including the Kolmogorov energy-cascade which typically prevails on Earth for the inertial regime, but has been challenged several times on Mars.
N-waves propagating through the Mars atmosphere
Authors: Chide Baptiste , Maurice Sylvestre , Jacob Xavier , Lorenz Ralph , Wiens Roger , Blanc-Benon Philippe , Murdoch Naomi , Mimoun David , Lanza Nina
Published: April 2023

One of the particular interest of the SuperCam microphone onboard the NASA’s Perseverance rover is that it is coupled with its own reproducible sound source, the blast waves generated by the SuperCam laser-induced plasma expansion. This unique emission-reception pair on Mars is used to investigate the propagation of spark-induced N-waves through the turbulent CO2-dominated Mars atmosphere. The analysis of waveforms shows large distortions over a burst of 30 subsequent shots, which is consistent with previous laboratory recordings of N-waves through thermal turbulence. Especially, this distortion leads to a scattering of the peak pressure amplitude, whose distribution can be fitted with a generalized gamma function. For bursts recorded farther than 4 m, the distribution gets asymmetric with a shift of the maximum toward the left of the median due to peaks amplified more than twice the median amplitude, likely due to caustics that randomly focus the acoustic wave. On the other hand, over a Martian year, the absolute peak pressure varies by ∼50% due to changes in the acoustic impedance and Rankine-Hugoniot conditions, due to the seasonal cycles of pressure and temperature at the surface of Mars.
What might we hear on other worlds? A free demonstration programme for planetaria
Authors: Leighton Timothy G. , Joseph Phil
Published: April 2023

In order to plan missions with acoustical sensors for other worlds, and to design those instruments appropriately, it is useful to predict the nature of the signals they might detect. Such predictions could, for example, identify in advance that a planned single microphone system should be replaced by a 3-microphone system, because the predictions indicate the dominance of uncorrelated non-acoustic (hydrodynamic) pressure fluctuations that need to be separated from the incident sound, allowing (in addition) its the direction of arrival to be estimated. Similarly, calibration errors could also be predicted resulting from the fluid loading experienced by the off-world microphone, or acoustical artifacts resulting from the presence of coupled waves in the structure supporting the microphone. One offshoot of generating such predictions was the ability to build a software package to provide to planetaria the ability to predict certain environmental sounds on other worlds and entertain the public by changing their voices to reflect how they would sound on another world, if they could speak and live. The interest of the public has always been key to ensuring policymaker support for space and extraplanetary exploration. This should be supported by rigorous science, or where guesses need to be made, these should be transparently communicated. This project endeavoured to do this through the aforementioned software package.
Seismo-acoustic coupling efficiency at the surface of Venus
Authors: Averbuch Gil , Houston Reyna , Petculescu Andi
Published: April 2023

The extreme conditions at the surface of Venus pose a challenge for monitoring the planet’s seismic activity using long-duration landed probes. One alternative is using balloon-based sensors to detect venusquakes from the atmosphere. This presentation assesses the efficiency of seismic-to-acoustic energy transfer from Venus' crust to its deep atmosphere. It is, therefore, restricted to immediate neighborhood of the planet's surface. In order to account for supercritical conditions near the surface, the Peng-Robinsonequation of state is used to obtain the acoustic wavenumber in the lower atmosphere. The energy transported across the surface from deep and shallow sources is two orders of magnitude larger than on Earth, pointing to a very strong seismo-acoustic coupling. For a more realistic scenario, we simulated the acoustic field generated in the lower atmosphere by the ground motion arising from a vertical array of subsurface point-force sources. The resulting transmission loss maps show a strong epicentral cone accompanied by contributions from leaky surface waves.
Considerations of undersea exploration of an extraterrestrial ocean
Authors: Eastland Grant
Published: April 2023

Hypothetical investigations and simulations of the potential effects to acoustic propagation and modal structures in oceans on extraterrestrial planets and moons are presented. Europa, one of the many moons of Jupiter is thought to have a water-based ocean that has a depth of 60 to 150 km and covered by a suspected 15 to 25 km thick ice sheet. Another moon of Jupiter, Ganymede, is the largest moon in our solar system is thought to have an underground saltwater sea 100 km deep. Titan, a moon of Saturn, is also thought to have a water-based sea under an ice sheet in addition to surface, rivers, lakes, and seas of hydrocarbons like methane. Exploration of such exotic environments will require great leaps in technology and a fundamental understanding of the physics of the environment. Understanding the acoustics of such environments will provide the mechanism to develop the advanced sensors needed for the exploration missions. The drive to explore such places could provide evidence of life beyond Earth, since where there is water, life is possible.
A lower frequency signal emitted from tornadoes based on a new mechanism
Authors: Liang Bin , Waxler Roger M. , Markowski Paul
Published: April 2023

Tornadoes have been shown to radiate infrasound to great distances. After using Lighthill's acoustical analogy to study sound generated by a numerical tornado, we found that there is a significant low-frequency signal between 0.1 Hz and 0.5 Hz. We hypothesized that there is a Kirchhoff vortex-like source at the center of the numerical tornado. Based on vortex sound theory, characteristic frequencies only depend on the strength of the vertical vorticity which can change at different heights of the tornado. Compared to real data analysis, there is a possibility that when a tornado occurs, infrasonic sensors can detect a significant increase in low-frequency signals. This hypothesis is being tested against data collected in the field during the passage of tornado-producing storms.
Theoretical investigation on the moving flame–sound interaction in a closed-open combustor
Authors: Guan Yiheng , Zhao Dan
Published: April 2023

Self-excited thermoacoustic instability is highly undesirable for power generation gas turbines, aero-engine afterburners, liquid-fuelled ramjet, and rocket motors. It is typically generated due to the constructive interaction between acoustic perturbations and the flame. It is a general practice to assume that the flame is non-moving and the combustor is typically assumed to be acoustically opened. In this work, we consider a closed-open thermoacoustic combustor with a moving flame. To better understand the physics between the acoustic disturbances and the moving flame, we theoretically investigate the moving flame-sound interaction. We find that the presence of the moving flame can amplitude the gaseous oscillations. Furthermore, the amplification process is shown to depend on the laminar burning velocity on the temperature and density of the combustible gas mixture into which the flame propagates. The sound source is shown to be the quadrupole mode. It radiates very little energy, if the flame dimensions are smaller than the wavelength of the sound produced. The present work shed lights on the sound generation from a moving flame and its interaction with sound.
The underlying mechanisms for voice discrimination across the life span
Authors: Zaltz Yael
Published: April 2023

Speech understanding in noisy conditions changes across the life span. One strategy that assists listening in multi-talker noise is to track the voice of the relevant speaker, based on his/her fundamental frequency (F0) and formant frequencies (reflecting vocal tract length). Thus, age-related differences in voice discrimination (VD) may explain some of the difficulties that children or older-adults have in speech-in-noise perception. The present experiments aimed to assess VD from childhood to old age and explore the underlying mechanisms for VD across ages. Four experiments assessed difference limens (DLs) for VD, using an oddball paradigm with two-down one-up adaptive procedure in quiet conditions (Two experiments, including 41 children, 36 young-adults, and 15 older-adults), amid speech-shaped noise (16 children, 24 young-adults, and 12 older-adults) and following different testing methods (32 children, and 31 young-adults). Working memory, attention, and speed of processing were also assessed. The poorest VD was shown for the youngest children and the older-adults, with better cognitive abilities and/or improved acoustic accessibility/resolution advancing VD for these groups. children and older-adults may engage more top-down (cognitive) and bottom-up (periphery) resources for VD compared to young-adults, which may partly explain their difficulties in understanding speech in multi-talker environments.
Examination of audiovisual prosody in cochlear implant recipients
Authors: Meister Hartmut , Winter Isa , Waechtler Moritz , Sandmann Pasale , Abdellatif Khaled
Published: April 2023

Prosody plays a vital role in verbal communication. It is important for the expression of emotions but also carries information on sentence stress or the distinction between questions and statements. Cochlear Implant (CI) recipients are restricted in the use of acoustic prosody cues, especially in terms of the voice fundamental frequency. However, prosody is also perceived visually, as head and facial movements accompany the vocal expression. To date, few studies have addressed multimodal prosody perception in CI users. Controlled manipulations of acoustic cues are a valuable method to uncover and quantify prosody perception. For visual prosody, however, such a technique is more complicated. We describe a novel approach based on animations via virtual humans. Such a method has the advantage that–in parallel to acoustic manipulations–head and facial movements can be parametrized. It is shown that animations based on a virtual human generally provide similar motion cues as video recordings of a real talker. Parametrization yields fine-grained manipulation of visual prosody, which can be combined with modifications of acoustic features. This allows generating both congruent and incongruent stimuli with different salience. Initial results of using this method with CI recipients are presented and discussed.
Effects of audible bandwidth and stimulus modality on emotional responses to sound
Authors: Picou Erin M.
Published: April 2023

A wide range of emotional responses is typical and important for overall well-being. Adults with hearing loss demonstrate a reduced range of emotional responses to non-speech sounds; their ratings of valence to pleasant and unpleasant sounds are less extreme than those of their peers with normal hearing. The purpose of this project was to explore the role of two potential explanations, limited audible bandwidth and emotional processing differences. Adults with normal hearing and sensorineural hearing loss rated their emotional responses (valence and arousal) to non-speech, affective sounds and pictures (in combination and in isolation). To explore the potential contribution of audible bandwidth, adults with normal hearing rated stimuli that were full bandwidth and also bandpass limited. In addition, adults with hearing loss were specifically recruited to include heterogeneous hearing loss configurations. Differences in ratings between auditory and visual stimuli provide insight into whether reduced emotional responses for adults with hearing loss are specific to audition or generalize to visual stimuli. Results demonstrate the importance of audition and audible bandwidth as key factors in emotional responses to pleasant, non-speech stimuli. These findings have important implications for designing interventions to support the listening needs of adults with hearing loss.
Exploring the impact of hearing loss through music, irony, and rhythm
Authors: Lo Chi Yhun , Russo Frank , Singh Gurjit
Published: April 2023

Hearing loss is associated with challenges such as listening in noise, misinterpreting emotion, distorted music perception, and poorer quality of life outcomes relative to hearing peers. Despite this, research examining perceptual abilities for individuals with hearing loss has overwhelmingly focussed on measuring a narrow representation of speech perception. These typically include tasks ranging from the perception of simple words-in-quiet to more complex speech-in-noise. However, the full range of human communication extends far beyond this. In this talk, we will present several studies exploring topics that extend beyond traditional and contemporary approaches to perception. First, a music training study for children with hearing loss that enhanced both speech and psychosocial outcomes. Second, a paralinguistic study examining irony comprehension in children with hearing loss. Finally, an examination of rhythm and speech correlates for older adults with hearing aids, and how this can inform the focus of future intervention studies. Findings from these studies underscore the importance of extending our focus beyond traditional perceptual outcomes.
The dependence of sound radiation on position of acoustic source in an enclosure
Authors: Jensen Naomi M. , Bacon Ian C. , Sommerfeldt Scott D.
Published: April 2023

In some applications, acoustic sources may be confined to a small enclosure but still radiating sound outwards through the enclosure. However, the sound power that is radiated from the enclosure may potentially be impacted by the location of the source within the enclosure and the properties of the enclosure. The dependence of source position on sound power radiated from the enclosure was investigated using a small rigid rectangular enclosure with a flexible aluminum panel as one of the sides of the enclosure. An acoustic source was moved to numerous locations in the enclosure and sound power measurements were made using the ISO 3741 standard. Results will be shown to numerically quantify the effect of acoustic source position on excitation of the aluminum sheet and radiated sound power. These results are used to develop a calibration curve between the sound radiate by the enclosed source versus the sound radiated by the source in a free field environment. This curve can be used in the development of an alternative method of determining sound power for a source.
Improving transmission through honeycomb panels through modal considerations
Authors: Swift S. Hales , Reinke Charles M. , Parikh Anup
Published: April 2023

Recent efforts centered at Sandia National Laboratories have demonstrated transmission of power and data through continuous metal media using vibration in connection with piezoelectric tiles; however, solid metal construction may be disadvantageous in structural contexts due to the greater mass needed to achieve given stiffness characteristics. Other common structural materials, on the other hand, such as aluminum honeycomb panels, may offer poor transmission possibilities when their characteristics are not appropriated accounted for in the selection of transducers. In this study, COMSOL simulations of the aluminum honeycomb panel materials were used to select transducers with resonance frequencies in proximity to the natural modes of the panel's honeycomb cells. This enabled improved transmission through the honeycomb panels in comparison to less targeted approaches. [SNL is managed and operated by NTESS under DOE NNSA Contract No. DE-NA0003525.]
Spatio-temporal evolution and precursory indicators of rock failure processes using acoustic emission tomography
Authors: Dong Longjun
Published: April 2023

The characterization of stress and crack development plays important part in monitoring disasters. To capture the instability enlightenment from the spatio-temporal evolution of rock damage, this paper constructs the velocity field of key nodes in the rock failure process with the active and passive collaborative acoustic emission (AE) tomography method. It realizes the exploration of the micro-crack propagation law and its potential connection with the stress environment, combining the velocity field, the AE density field, and the energy field. Furthermore, from the spatial integrity and directional evolution of the velocity field, the mutation trend coefficient (MTC) and deformation coefficient (DC) of the velocity field are proposed as precursor indicators of rock instability, respectively. Results show that the anisotropy of the velocity field increases with the aggravation of rock damage, and the stress environment controls the spatial heterogeneity of the velocity field. The most important feature of spatial heterogeneity is that there are the continuous decrease and extension of low-velocity regions and the transformation from the high velocity to the low velocity. Real-time acoustic emission monitoring of the velocity field with MTC and DC can early identify rock instability precursors and principal stress direction, which provides vital pre-alarm information for geotechnical engineering.
Voice production in virtual reality: Effects of room size and fullness
Authors: Nudelman Charles J. , Bottalico Pasquale
Published: April 2023

This study explores the influence of visual input on voice production in virtual reality with healthy participants. The effects of the size and fullness of various virtual rooms on acoustic voice parameters and self-reported vocal status ratings are examined. Speech samples from healthy participants were recorded in six virtual conditions. After each condition, the participants provided subjective vocal status ratings on visual analog scales. The voice recordings were processed to calculate objective voice acoustic parameters including sound pressure level, standard deviation of fundamental frequency, mean pitch strength, time dose, and cepstral peak prominence smoothed. The effects of the virtual reality conditions on these acoustic parameters and the vocal status ratings were analyzed. The largest virtual room resulted in significantly higher (worse) vocal status ratings. The size of the virtual rooms had statistically significant effects on mean pitch strength and cepstral peak prominence smoothed, among associations with other objective voice acoustic parameters. This study provides evidence that larger and more full virtual rooms contribute to higher (worse) vocal status ratings and changes in objective voice parameters in healthy speakers.
Development of an algorithm for characterizing speech production patterns as context-based Cue Production Profiles
Authors: Torres Deborah , Choi Jeung-Yoon , Shattuck-Hufnagel Stefanie
Published: April 2023

A given word or sound can take on a wide range of acoustic forms in conversational speech, and these patterns of variation are systematic with context. This substantial variability poses a problem for modeling human speech perception, but it can also be highly informative if it can be measured quantitatively; surface phonetic patterns can be used to characterize different speakers, dialects, speaking styles and speech disorders, as well as context-driven variation within a speaker. Adopting the view that individual acoustic cues provide a useful vocabulary for describing these variation patterns, we are developing an algorithm for tabulating the range of acoustic cue production patterns for each phoneme, in a corpus of recorded speech, with the potential for extension to words and phrases. This algorithm will enable the determination of key factors that govern systematic speech variation, including segmental, prosodic and lexical contexts, which can be used to create a profile for a speaker or defined population of speakers, i.e., a Cue Production Profile.
Variable production of voiceless sonorants in Hakha La
Authors: Ziegler Grayson , Flego Stefon M. , Berkson Kelly H.
Published: April 2023

Research on Tibeto-Burman voiceless sonorants often centers on nasals, which are standardly described as having two language-specific phonetic realizations: “voiceless unaspirated” nasals have a period of voicelessness and nasal airflow during closure followed by voicing prior to oral release ([m̥m]), while “voiceless aspirated” nasals have a period of voicelessness and nasal airflow optionally preceded by a voiced period, and voicing following oral release ([(m)m̥ʰ]) (e.g., Bhaskararao and Ladefoged, 1991; Chirkova et al., 2019). Little language-internal inter- or intra-speaker variation has been reported. An exception is South Central Tibeto-Burman (Chin) languages, such as Hakha Lai, in which voiceless nasals reportedly exhibit considerable inter- and intra-speaker variation (Hoffmann, 2018; Ziegler et al., 2022). As thorough investigation of this variation is absent from the existing literature, this paper investigates acoustic data from 9 native speakers of Hakha Lai (3M, 6F). Data for all voiceless sonorants (nasals, lateral, and rhotic) is presented, revealing that: (1) voiceless nasals in Hakha Lai indeed show a high degree of variation in the phasing of laryngeal and supralaryngeal gestures, defying the two-type approach; and (2) this variation extends to voiceless laterals and rhotics, which show similar bi-phasic and even tri-phasic variation.
Preschoolers with hearing loss have asymmetries in the rate of initiating conversations
Authors: VanDam Mark , Thompson Lauren , Jeson David , Brock Aleah , Wilson-Fowler Elizabeth , Bass-Ringdahl Sandie , De Palma Paul
Published: April 2023

Recent work has shown that preschool children initiate more conversations than their mothers and fathers. It has also been shown that boys and girls initiate conversations at about the same rate. It is not known if children with hearing loss initiate conversations at comparable rates to their typically-developing peers, or whether boys and girls with hearing loss differ. In this work, we collected daylong audio recordings from preschoolers with hearing loss using a body-worn audio recorder. We used automatic speech processing routines on the 7600 + hours of audio to identify talkers and conversational turns in their natural family settings. We examined how children with hearing loss initiate conversations compared with their typically-developing peers. We found no difference in rate of conversation initiation by hearing status or sex. We did find that regardless of hearing status or sex, children consistently initiate more conversations with their mothers than with their fathers. Results bear on the role of conversational exchanges, joint attention, and the auditory experiences during speech and language development in children with hearing loss.
Acoustic analysis of voicing errors in children with childhood apraxia of speech
Authors: Swartz Michelle T. , Koenig Laura , Hitchcock Elaine R.
Published: April 2023

Childhood apraxia of speech (CAS) is a complex neurological speech sound disorder (SSD) that involves impaired speech motor planning and programming. Speech characteristics of CAS include difficulty sequencing speech movements in the absence of muscle weakness resulting in segmental and suprasegmental speech deficits. Past work indicates that children with CAS are delayed in acquisition of voicing contrasts, and are often perceived to produce errors or distortions of voicing. However, not all past studies employed acoustic analyses to assess voicing characteristics in CAS. This study will use voice onset time (VOT) to analyze the voicing contrast in children with CAS (aged 8;0 to 15;11) compared to peers with residual speech sound disorder (RSSD) and typical development (TD). VOT of initial consonants from twelve children (CAS = 4, RSSD = 4, TD = 4) will be assessed in words of varying length, stress pattern and target complexity. Given that children with CAS are known to experience greater articulatory breakdowns in phoneme sequences of increasing length and complexity, we expect that group differences will increase with task complexity. Overall, based on past work, we also predict that children with CAS will demonstrate shorter and/or more variable VOTs for plosives than children with SSD and TD.
Gender-specific covariation of voicing cues in stops: Girls are leading the sound change
Authors: Arzbecker Lian J. , Goebel Riley , Jacewicz Ewa , Fox Robert A.
Published: April 2023

Multiple cues to stop coda voicing in English can be distributed over larger domains, covarying at a long distance within a syllable (Hawkins and Nguyen, 2004). Our recent work uncovered systematic temporal relationships between voiced and voiceless consonants in the coda and the syllable-initial /b/, indicating that information about coda voicing—phonetic detail cueing the phonological voiced/voiceless contrast—is already available at the onset (Jacewicz et al., 2021). These systematic long-distance cues to coda voicing are further altered by regional dialect variation that defines the relative durations of /b/-closure and (un)broken voicing in this closure (extending from the preceding sonorant). However, systematic dialect effects were found in adult females and males (Arzbecker et al., 2022) but not in girls (Jacewicz et al., 2021). Here, we present the corresponding acoustic data from 8 to 12-years old boys (n = 47). The results show that boys have retained the pronunciation of men: They produced more voicing in the closure (83%) than girls (55%), and the closures of Southern boys were almost fully voiced, following the dialect-inherent pattern. Adding the missing link, the current study provides evidence that girls are leading the sound change and the covariation of voicing cues is gender specific.
Using a production-center methodology to probe syllabic constituency
Authors: Lin Yu-Jung , de Jong Kenneth J.
Published: April 2023

Research on speech production in the P-center paradigm (Rapp, 1972) explores how speakers produce various items with temporal regularity, as guided by a metronome. Studies find a regular pattern in which, with small offsets created by different types of onset consonants, and by material appearing after the vowel, the acoustic onsets of stressed vowels are aligned with the metronome. The current paper examines the extent to which language structure, in the form of syllabic constituency, affects speech in metronome alignment. Previous work (Lin, 2020) finds strong evidence that Mandarin speakers associate approximants with neighboring vowels, contra English wherein labial approximants (as in quick) appear to associate with the previous onset consonants. In the current work, 6 speakers of Mandarin produced syllabic forms in time to a metronome. Stimuli included items with and without vowel-like approximants before the vowel. Mandarin productions show strong evidence for metronome alignment with the onset of these approximants, as would be the case if a vowel complex forms the main unit of alignment and approximants are part of this vowel complex. Analysis of the parallel English productions is currently underway, and will be reported.
Duration impedes loss of the palatal lateral in Languedocien as compared to Gascon
Authors: Owens Kaitlyn
Published: April 2023

Previous acoustic evidence suggests loss of /ʎ/ in the Gascon dialect of Occitan is due to contact with French, however this study probes acoustic evidence for the notable retention of /ʎ/ in the Languedocien dialect. Both dialects of Occitan have been in intense long-term contact with French and maintain /ʎ/ in positions where it was lost in the development of French. We analyze 181 tokens of /ʎ/ in oral narratives performed in the contemporary dialects of Gascon and Languedocien in the OcOr Corpus by using mixed-effects linear regression to predict the durations of the lateral and glide segments in word-medial positions in tokens of [ʎj], the most frequently realized variant of /ʎ/ in both dialects. By examining the durations of both the glide-like transition and lateral segment in these tokens, we find that the lateral segment of these variants is longer in Languedocien than other segments in either dialect (p = 0.0009). We propose that the increased duration of the lateral segment renders the lateral feature of /ʎ/ more salient in Languedocien than in Gascon. Thus, this increased duration aides in impeding the loss of the lateral segment due to contact, given that synchronic perception may influence diachronic sound change.
Neural networks’ posterior probability as measure of effects of alcohol on speech
Authors: Wayland Ratree , Tang Kevin , Wang Fenqi , Vellozzi Sophia , Sengupta Rahul
Published: April 2023

Intoxication has a well-known effect on speech production. Lester and Skousen (1974) reported that the place of articulation for /s/ is retracted and /tʃ/ and /ʤ/ are deaffricated (i.e., substituted by a non-affricate segment) in drunken speech. Zihlmann (2017) further established the robustness of deaffrication as it cannot be consciously suppressed under intoxication. Using these prevalent speech errors as test cases, this study extends a phonologically-informed neural network approach to the study of intoxicated speech. The approach has success in measuring pathological speech and lenition patterns in healthy speakers. Degrees of place retraction for /s/ and deaffrication of /tʃ/ and /ʤ/ are estimated from posterior probabilities calculated by recurrent neural networks trained to recognize [anterior], [continuant] and [strident] features. When applied to a corpus of alcohol English speech, preliminary results suggested that sober versus drunken state could be reliably predicted by the three posterior probabilities. The directions of the effects are largely in line with previous studies. For example, /tʃ/ and /ʤ/ are more fricated (higher strident and continuant probabilities), and /s/ is more retracted (lower anterior probability) in drunken compared to sober speech. The results suggest that the intoxicated speech can be reliably quantified by this new approach.
Lexical tone and vowel duration in San Sebastián del Monte Mixtec
Authors: Weller Jae , Steffman Jeremy , Cortés Félix , Mantenuto Iara
Published: April 2023

Vowel duration has been shown to vary as a function of lexical tone (Gandour, 1977; Gordon, 2001; Yu, 2010). Here we explore the relationship between tone and duration in a dialect of Mixtec. San Sebastián del Monte Mixtec (SSM) has three tones which link to individual moras: H(igh) M(id) L(ow). These can be combined in a long (bimoraic) vowel, in some cases creating contour tones: HH MM LL HL ML LM (Cortes et al., forthcoming). Audio recordings of 14 native speakers (9F, 5M) were collected, producing 264 utterances with target words in phrase-medial position. The corpus includes all tones, as well as all vowels /i,e,a,o,u/ across four possible word shapes (with several lexical gaps). With mixed effects modeling, we find that duration varies as a function of tone with vowel and onset consonant controlled for (1) L tones are shorter than M and H tones in mono-moriacsyllables, and (2) tones in bimoraic (long vowel) monosyllabic words vary in duration as well: {MM,HH,LH} > {ML,LM,LL}. First vowels are longer, consistent with stress on the initial syllable. We further discuss the relation between duration, mean F0, and F0 range, and the influence of vowel features and preceding consonant on duration.
Acoustic characteristics of variation in vowels in Assamese
Authors: Ray Jupitara
Published: April 2023

This study provides an overview of acoustic characteristics of the vowel system in three regional varieties of Assamese. Recordings were made of 24 speakers producing the vowels /i/, /e/, /ɛ/, /ɑ/, /u/, /ʊ/, /o/ and /ɔ/ from a wordlist of 128 tokens. The speakers came from three locations in Assam, India: namely Lower Assam, Upper Assam, and Guwahati, and were balanced for region, sex, age, and education background. Acoustic analysis was conducted in Praat. First, the formant settings for male and female speakers were adjusted accordingly: 5500 Hz for female speakers and 5000 Hz for male speakers, where the vowel onsets and offsets were identified perceptually in the waveform, coinciding with the spectrogram in Praat. First and second formants were measured at the midpoint of the vowels for each of the 24 talkers, for a total of 9216 formant measurements. Formant measurements were then plotted on an F1xF2 chart using R. Findings show that Upper Assamese speakers had a high /ʊ/ production, while Lower Assam speakers had a low /ʊ/ in the acoustic space, while within Guwahati, more educated speakers produced /ʊ/ that was higher compared to speakers with less education.
Automatic detection of nasalization in speech via cue-based analysis
Authors: Kong Blisse , Choi Jeung-Yoon , Shattuck-Hufnagel Stefanie
Published: April 2023

Modern speech recognition systems are powerful, but it is not simple to understand the mechanisms by which they model speech, or precisely how they make use of acoustic cues. Moreover, a system for the explicit detection of individual acoustic cues may be useful not only for speech recognition but for understanding the principles that govern sub-phonemic patterns of surface-phonetic variation, and how specific cue patterns may reflect speech disorders. This report describes a transparent, acoustic cue-based nasalization detection module, that can be used to find not only nasal consonants but also nasalization wherever it appears, e.g., within a vocalic region. We lay out a framework for extracting measurements that are key to detecting nasalization, in particular, the nasality-related spectral peaks P0 and P1, and confirm the utility of these measurements for nasality detection in spoken words. In particular, we present a pre-processing and cue-value extraction framework, and propose a Gaussian Mixture Model-based approach to detect the regions of nasalization in a speech signal. This work on a detection module for nasalization is part of a larger effort to develop a speech recognition system that is based on landmarks and other acoustic cues.
Speech perception and children with speech sound disorder: An assessment of non-errored speech sounds
Authors: Hitchcock Elaine R. , Koenig Laura
Published: April 2023

Previous studies assessing speech perception in children with speech sound disorder (SSD) suggest inconsistent, if any, differences from typically-developing peers (TD). However, others suggest that children with SSD perceive inaccurate productions as acceptable variants of a sound. Currently, limited research explores speech perception of non-errored sounds in children with SSD compared to TD peers. This study assesses how distributional characteristics of naturally produced child speech stimuli, collected from six 2–3-year-old English-speaking children, might impact listening behavior of children with SSD for non-errored sounds. Stimuli included six exemplars per speaker and VOT categories of short-lag /b d/, short-lag /p t/, long-lag /b d/, long-lag /p t/. For each POA and VOT group, /b d/ and /p t/ VOTs were bimodally distributed (shorter for voiced targets), separated by a minimum 5 ms gap. We will compare perception results for TD children and children with SSD (ages 6;0–10;11). Earlier findings showed high accuracy in adults and TD children for targets with appropriate VOT values with adults slightly outperforming children. We hypothesize that children with SSD will demonstrate similar accuracy levels between groups when VOT values are appropriate for the target, and slightly greater response variability and group differences for inappropriate VOTs.