bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of the instrumentalist on the sound of the concert harp
Authors: Le Carrou Jean-Loïc , Chadefaux Delphine , Chomette Baptiste , Fabre Benoît , Gautier Francois , Leclère Quentin
Published: October 2015

The sound of musical instruments comes from a subtle mix between its mechanical behavior and its interaction with the instrumentalist. For the concert harp, the instrumentalist defines the initial conditions which determine the vibratory contents of the strings. This vibration is then radiated through the soundboard and the sound-box over a range of 7 octaves. Besides, this radiation may be affected by the instrumentalist's physical presence next to the instrument. The aim of the talk is to show, thanks to ten years of research on the physics of the concert harp, how the instrumentalist and the instrument act in the sound from the instrumentalist gesture to the radiated sound. For that, specific set-up and models are carried out in order to carefully analyze each important step of the sound production : plucking, strings coupling, dynamical behavior of the soundboard and radiated sound. These studies are performed when the instrument is isolated, without the harpist, or in playing situation in a musical context. The results show, for instance, that the instrumentalist gesture is a part of the spectral content of the sound, whereas the instrument's design has consequences on the directivity of each string’s partial.
Experiences evaluating acoustics in occupied hospitals
Authors: Miller-Klein Erik , Roe Matthew
Published: October 2015

The acoustic performance of patient rooms for four fully operational Veterans Affairs hospitals were completed over the past year. The nurse and facility managers goal was to identify the causes and solutions to improve the “quiet at night” scores. The testing included measuring speech privacy between patients and staff, background sound, occurrence rate of noise impacts during nighttime hours, and reverberation time. The testing procedures and methods were completed in cooperation with the hospital staff to optimize accuracy of the results while maintaining patient privacy, safety, and comfort. This included short duration pink noise measurements from room to room, and from nurses stations to patient care areas; these measurements provided accurate speech privacy metrics, though required direct approval and coordination with the nursing staff. The occurrence rate and background noise level was evaluated with 12 hour continuously logging sound level meters in patient rooms on tripods near patients with the approval of patients and guidance of nursing staff.
Opportunity for the session's participants to share their insights and lessons learned
Authors: Madaras Gary , Holtrop Jim
Published: October 2015

This session on measuring sound fields in healthcare environments will conclude with an open microphone period whereby participants can contribute their brief insights and lessons learned from their past experiences performing acoustical measurements in healthcare settings. Contributions should be limited to measurement methods, standards, and interpretation of findings.
Numerical modeling of acoustic propagation in Harbor porpoise’s (Phocoena phocoena) head
Authors: Wei Chong , Au Whitlow W. , Ketten Darlene , Song Zhongchang , Zhang Yu
Published: October 2015

Harbor porpoises (Phocoena phocoena) use narrow band echolocation signals for locating prey and spatial orientation. In this study, acoustic impedance values of tissues in the porpoise’s head were calculated from the Hounsfield Units (HU). A two-dimensional finite element model was set up base on the computed tomography (CT) scan data to simulate the acoustic propagation through animal’s head. The far field transmission beam pattern in the vertical plane and the waveforms of the receiving points around the forehead were compared with prior measurement results, the simulation results were qualitatively consistent with the measurement results. The role of the main structures in the head such as air sacs, melon and skull in the acoustic propagation was investigated. Additionally, the relative sound pressure level within the porpoise’s sonar field across the transitional near and far field was obtained to compare with the spherical spreading loss.
Use of vibrational duetting mimics to trap and disrupt mating of the Asian citrus psyllid, a devastating pest in Florida groves
Authors: Mankin Richard , Rohde Barukh
Published: October 2015

The Asian citrus psyllid (ACP) is the primary vector of a devastating disease of citrus, huanglongbing, and efficient surveillance of ACP at low population densities is essential for timely pest management programs in Florida. ACP males search for mates on tree branches by producing vibrational calls that elicit duetting replies from receptive females. The males then search for the location of the reply. We constructed a vibration trap by using a microcontroller with signal detection software, a contact microphone to detect ACP calls, and a piezoelectric buzzer to produce calls. The buzzer plays back a female reply when a male calls, which stimulates the male to search and find it. In this report, we discuss the construction and operation of the vibrational trapping system. In addition, we discuss methods that have been developed in laboratory studies to interfere with ACP courtship and mating. Our goal is to develop field-worthy systems that target ACP infestations and reduce their populations.
Observations on the mechanisms and phenomena underlying vocalizations of the gray seals
Authors: Nowak Lukasz , Skora Krzysztof E.
Published: October 2015

Gray seals vocalize both underwater and above the water surface using variety of sounds. The analysis of the differences in acoustic parameters of the emitted sounds suggests that the underlying phenomena may involve several different, independent mechanisms, which have not been yet investigated and understood. The aim of the present study is to introduce some important conclusions regarding those mechanisms and phenomena, based on the results of the original, long-term experimental investigations, and observations carried out at the sealarium of the Hel Marine Station of the University of Gdansk. Several thousands of vocalizations emitted by the mature specimens and cubs were recorded above and beneath the water surface, and analyzed for their acoustic parameters using the dedicated, developed software. The observations also involved video recording combined with synchronous acquisition of underwater sounds, which allowed to link the acoustic phenomena with the specific behavior of the animals. Based on the obtained results, the equivalent mechanical models of the corresponding anatomical structures responsible for generation of various sounds are proposed. An own, original classification of the vocalizations of the gray seals, based on the assumed separation of the involved generation mechanisms, is introduced.
Neural responses to songbird vocalizations in the nucleus taeniae of the amygdala in Bengalese finches
Authors: Fujii Tomoko , Ikebuchi Maki , Okanoya Kazuo
Published: October 2015

Emotions are important psychological processes that induce adaptive behavior in response to communication signals. Many species of songbirds form complex social relationships and communicate with others through a large variety of vocal sounds. Thus, songbirds could be a good model to search for the neural basis of emotion especially in a context of communication. Anatomical studies have shown that the nucleus taeniae of the amygdala (TnA) in birds corresponds to the medial amygdala in mammals. While the amygdala is suggested to be involved in recognition of conspecific vocalizations in rats and bats, the function of the TnA still remains unclear. The present study aimed to explore auditory response properties of the songbird TnA by electrophysiology. We examined activity of the Bengalese finch TnA neurons during the presentations of conspecific and heterospecific vocalizations, as well as synthesized sound. We demonstrated for the first time that a population of TnA neurons exhibited selective auditory responses to songbird vocalizations. Our findings suggested involvement of the songbirds TnA for the recognition of communicative sounds. Further investigation into the TnA response properties should be fruitful in understanding the relationship between emotion and vocal signals in animals. [Work supported by JSPS KAKENHI Grant # 26240019.]
Auditory sensitivity shift by attention in Mongolian gerbil
Authors: Miyawaki Hiroyuki , Nakayama Ayako , Hiryu Shizuko , Kobayasi Kohta I. , Riquimaroux Hiroshi
Published: October 2015

Mongolian gerbil, Meriones unguiculatus, communicate with others by various sounds. About 80% of those sounds range over 20 kHz. A threshold of hearing in this range, however, was about 20 dB higher than their most sensitive frequency (1 to 16 kHz). We proposed a hypothesis that the auditory sensitivity heightened when gerbils communicated with others. In order to test the idea, a cochlear microphonics (CM) was recorded under various behavioral context as a measure of auditory sensitivity. Under paired condition, a subject was set with another gerbil. The condition simulated the subject gerbils in their group, and the subject was considered to pay attention to sounds of the company. The CM response under the situation was higher than under single situation. Then, we investigated if the CM increase was specific under the situation. Subject was trained to pay attention to a sound of conditioned stimulus by electric shock as a negative reinforcer. The sound worked as an alarm sound for gerbils. The CM response increased while the gerbil was paying attention to the sound. Those results suggest that the sensitivity of auditory periphery is raised by attention in various behavioral contexts.
Vocal plasticity after laryngeal nerve lesion in rodent
Authors: Iwabayashi Hiroki , Hiryu Shizuko , Kobayasi Kohta I. , Riquimaroux Hiroshi
Published: October 2015

Several species of animals, human, bat, and songbird adaptively control and change their spectro-temporal structure of vocalizations depending on auditory feedback. On the other hand, most of the common laboratory rodent generally vocalize relatively simple sound, and have been regarded as having only limited or no vocal plasticity. In this experiment, we conducted unilateral mutilation of the inferior laryngeal nerve in Mongolian gerbil, Meriones unguiculatus, and recorded the effect of surgery and recovery of vocalization for about 2 months for evaluating their vocalization plasticity. Mongolian gerbil have several types of vocalization. A short (<50 ms) high frequency (>25 kHz) vocalization, called “greeting call,” is the most commonly observed in their colony. After mutilation of the nerve, they stopped producing greeting call. From 18 days after surgery (18 DAS) recovery began; spectro-temporal structure of high frequency vocalization altered day by day, and on 66 DAS they were able to vocalized calls similar to greeting call. Currently, we are investigating role of audition on the recovery by combining the laryngeal neurotomy and auditory deprivation. Neomycin was administrated in order to deafen the gerbil. We will discuss if auditory feedback is capable to modify vocal output in the rodent.
Analysis of bearings of vocalizing marine mammals in relation to passive acoustic density estimation
Authors: Vernon Julia A. , Miksis-Olds Jennifer L. , Harris Danielle
Published: October 2015

The use of passive acoustic monitoring in population density estimation of marine mammals is a current area of interest, providing an efficient and cost-effective alternative to visual surveys. One challenge that arises with this method is uncertainty in the distribution of individuals. With large arrays where instruments are placed randomly with respect to the animals, it is often assumed that animals are uniformly distributed with respect to the instruments; however with sparse arrays this assumption is likely violated and could lead to bias in the density estimates. Distribution can be better determined through consideration of the horizontal azimuths or bearings of vocalizing animals. This paper presents bearing estimates of fin whales around Wake Island in the Equatorial Pacific Ocean, using ambient recordings from the Comprehensive Nuclear-Test Ban Treaty Organization (CTBTO) hydrophones at this location. Bearings were calculated for calls detected automatically. Multiple automatic detectors were assessed for optimal performance. Spectrogram correlation was found to produce the best results and bearings were calculated on calls detected with this method. The bearings were calculated using time delay information from the cross-correlation of received signals. Seasonal variation in animal distribution is also discussed. [This work was supported by the Office of Naval Research.]
Estimation of low frequency sound attenuation in marine sediments
Authors: Duan Rui , Chapman N. Ross , Yang Kunde , Ma Yuanliang
Published: October 2015

This paper presents a method for estimating low frequency sound attenuation from information contained in normal modes of a broadband signal. Propagating modes are resolved using the time-warping technique applied to signals from light bulb sound sources deployed at relatively short ranges of 5 and 7 km in the Shallow Water ’06 experiment. A sequential inversion approach is designed that uses specific features of the acoustic data that are highly sensitive to specific geoacoustic model parameters. The first feature is the modal group velocity which is inverted for sediment sound speed and sediment layer thickness. The second feature is the modal amplitude function which is inverted for water depth and receiver depths. The third feature is related to the modal amplitude spectrum and is inverted for source depth and sound attenuation. In each subsequent stage, estimates from the previous stage(s) are used as known values. The sequential inversion is stable and generates geoacoustic model parameter estimates that agree very well with results from other experiments carried out in the same region. Notably, the inversion obtains an estimated value of 0.08 dB/λ in the band 120–180 Hz for the de-watered marine sediment characteristic of the continental shelf at the site.
Environmental inversion using bowhead whale calls in the Chukchi Sea
Authors: Warner Graham A. , Dosso Stan , Hannay David , Dettmer Jan
Published: October 2015

This paper estimates environmental properties of a shallow-water site in the Chukchi Sea using bowhead whale calls recorded on an asynchronous cluster of ocean-bottom hydrophones. Frequency-modulated whale calls with energy in at least two (dispersive) modes were recorded on a cluster of seven hydrophones within a 5 km radius. The frequency-dependent mode arrival times for nine whale calls were used as data in a Bayesian focalization inversion that considered the whale locations and range-independent environmental properties (sound-speed profile, water depth, and seabed geoacoustic profile) as unknown. A trans-dimensional inversion over the number of points defining the sound-speed profile and subbottom layers allows the data to determine the most appropriate environmental model parameterization. The whale-call instantaneous frequency, relative recorder clock drifts, and residual-error standard deviation are also unknown parameters in the inversion which provides uncertainty estimates for all model parameters and parameterizations. The sound-speed profile shows poor resolution but the thickness and sound speed for the upper sediment layer are reasonably well resolved. Results are compared to an inversion of controlled-source (airgun) dispersion data collected nearby which showed higher environmental resolution.
Three-dimensional and real-time two-dimensional topological imaging using parallel computing
Authors: Bachmann Etienne , Jacob Xavier , Rodriguez Samuel , Gibiat Vincent
Published: October 2015

We present the Fast Topological IMaging that has shown promising results to quickly process a picture by sending an ultrasonic plane wave within an unknown medium. This imaging algorithm is close to adjoint-based inversion methods but relies on a fast calculation of the direct and adjoint fields formulated in the frequency domain. The radiation pattern of a transducer array is computed once and for all, and then the direct and adjoint fields are obtained as a simple multiplication with the emitted or received signals, in Fourier domain. The resulting image represents the variations of acoustic impedance, and therefore highlights interfaces or flaws. Real-time imaging and high definition visualization both imply an expensive computation cost, that led us to implement this method on GPU (Graphics Processing Unit). Thanks to a massively parallel architecture, GPUs have become for ten years a new way to implement high performance algorithms. We used interoperability between OpenGL and CUDA to enable a real-time visualization. Experimental results in 2D/3D obtained with scalar waves are presented. At this time, the method has been implemented for acoustic waves in fluids, with an initial homogeneous medium, but it can be extended to elastic media and more complex configurations.
Temperature dependence of shear wave speed in a viscoelastic wormlike micellar fluid
Authors: Dayavansha E. G. Sunethra K. , Labuda Cecille , Gladden Joseph R.
Published: October 2015

Wormlike micellar fluids are viscoelastic and can support shear waves. Phase transitions of the micellar aggregates are temperature dependent and can manifest as sharp changes in the shear wave speed as a function of temperature. In this work, the variation of shear speed with temperature of 200 mM CTAB/NaSal micellar fluid in a 5:3 ratio was studied. The dependence of shear wave speed on time between fluid synthesis and measurement was also investigated. Shear wave propagation through the fluid was observed as a time varying birefringence pattern by using a high speed camera and crossed polarizers and shear speed was calculated by edge tracking and wavelength measurement techniques. A gradual increase in shear wave speed was observed in the temperature range 20—40 °C. A phase transition was observed to occur between 6 and 7 °C. There was no evidence of variation of shear wave speed with time. The implications of the shear wave speed variation over a wide temperature range will be discussed.
Guided wave velocity sensitivity to bone mechanical property evolution in cortical-marrow and cortical-trabecular phantoms
Authors: Abid Alexandre , Thakare Dhawal , Pereira Daniel , Rajagopal Prabu , Fernandes Julio , Bélanger Pierre
Published: October 2015

Guided waves methods are sensitive to the mechanical properties of the material into which they are propagating. Guided waves methods are promising to detect osteoporosis; they are cost effective and do not expose the patient to radiation. Numerous studies have focused on the first arriving signal using a plate approximation. The aim of this study is to identify the best frequency/mode combinations for cortical-marrow and cortical-trabecular cylinder phantoms based on the sensitivity of the mode to mechanical property changes. Two different setups were used, axial transmission in a small diameter cortical-marrow phantom and circumferential propagation in a larger diameter cortical-trabecular phantom. Experiments for each method were carried out with in-plane and out-of-plane excitation, using frequencies from 50 to 200 kHz and were in good agreement with a 3D finite element model and dispersion curves extracted using semi-analytical finite element modeling. The modes’ velocity was identified using either first zero crossing, short time Fourier transform or 2D Fourier transform. The evolution of the mechanical properties from a healthy bone to an osteoporotic bone was simulated using the finite element models. The results of this study will be used to further develop the technique using highly sensitive mode and frequency combinations.
An experimental study on the effect of temperature on the acoustic properties of cranial bone
Authors: Hughes Alec , Hynynen Kullervo
Published: October 2015

Transcranial focused ultrasound is increasingly being used as an alternative non-invasive treatment for various brain disorders, including essential tremor, Parkinson's disease, and neuropathic pain. These applications necessitate an understanding of the complex relationship between temperature and acoustic properties of cranial bone. In particular, the longitudinal speed of sound and attenuation coefficients will be investigated. In this study, ex vivo skull caps were heated to temperatures ranging from 20 to 50 °C, and ultrasound pulses were transmitted through the skull caps using a spherical transducer of 5 cm diameter and 10 cm focal length, at clinically relevant frequencies of 0.836 and 1.402 MHz. A thin Mylar film was placed at the focus, and a laser vibrometer was used to receive the ultrasound pulse transmitted through the skull. It was found that there was a measurable change in the phase and amplitude of the received signal, implying a change in both the speed of sound and attenuation of the bone at different temperatures. It was also found that these changes were completely reversible. These results imply that at sufficiently high cranial bone temperatures, the assumption of temperature-independent acoustic properties of bone may become invalid.
Assessing dental implant stability using quantitative ultrasound methods: Experimental approach and numerical validation
Authors: Vayron Romain , Haiat Guillaume
Published: October 2015

Dental implants are widely used for oral rehabilitation. However, there remain risks of failure that are difficult to anticipate. The objective of this study is to investigate the potentiality of quantitative ultrasound (QUS) to assess dental implant implant stability. To do so, the implant is initially completely inserted in the proximal part of a bovine humeral bone sample. The 10 MHz ultrasonic response of the implant is then measured and a quantitative indicator I is derived based on the rf signal obtained. Then, the implant is unscrewed by 2π radians and the measurement is realized again. The procedure is repeated seven times and the indicator is derived after each rotation of the implant. Analysis of variance (ANOVA) (p < 10−5) tests revealed a significant effect of the amount of bone in contact with the implant on the distribution of I. In parallel, a finite element model is developed in order to model the ultrasonic propagation in the implant surrounded by bone tissue. The results show the feasibility of our QUS device to assess implant primary stability. A good agreement is obtained between experimental and numerical results. This study paves the way for the development of a new approach in oral implantology.
Nonlinear acoustic response of stand-off tubes used in acoustic pressure measurements—Part II: Analysis
Authors: Quinlan John M. , Scarborough David , Rehl Anthony , Zinn Ben
Published: October 2015

Rocket engine combustion instabilities, which lead to rapid engine failure through enhanced heat transfer rates and high-cycle fatigue, continue to be the most serious concern facing engine designers. Experimental testing and pressure measurements remains the best approach to determine the susceptibility of an engine design to acoustically coupled combustion instabilities. But, the harsh, high-temperature environment requires remotely mounting dynamic pressure transducers to the engine’s main chamber using “sense-tubes.” Experiments reveal that the acoustic response of the sense-tube is highly nonlinear due to the area-contraction at the connection point between the engine and sense-tube. This nonlinearity leads to large discrepancies between the combustor's actual and the remotely measured acoustic amplitudes. Our aim was to develop an accurate, nonlinear sense-tube acoustic response model including steady flow effects. Therefore, the governing equation for the area-contraction pressure drop was approximated using a Fourier based technique to develop expressions for the steady and acoustic pressure drop across the area change. The acoustic pressure drop model was then incorporated into a response model for the tube. Measurements of the acoustic response of the area-contraction without mean flow agree well with predictions of the developed model.
A stepped-plate radiator as a parametric array loudspeaker
Authors: Hwang Yonghwan , Moon Wonkyu
Published: October 2015

A parametric array loudspeaker can generate a high directional audible sound beam in the air by the nonlinear acoustic interaction widely known as a “Parametric Array.” The advantage of the parametric array phenomenon is that it creates a narrow beam using the small aperture of an acoustic radiator. It can be used in many applications, including high directivity communication systems. However, the sound pressure level generated by the parametric array is very low, which necessitates a high efficiency and intensity of sound. This paper describes the application of a stepped-plate radiator in a parametric array loudspeaker. The stepped-plate radiator has two resonance frequencies (f1 = 75 kHz, f2 = 85 kHz) in the design frequency region, and three different steps that compensate for the phase difference in the flexural vibrating plate. This allows the generation of high directivity audible sound in the wide flat radiation bandwidth of the audible frequencies range (100 Hz to 16 kHz, difference frequency waves with equalization). [Work supported by ADD (UD130007DD).]
Military Standard 1474E: Design criteria for noise limits vs. operational effectiveness
Authors: Amrein Bruce E.
Published: October 2015

In April 2015, the U.S. Department of Defense (DoD) published a significant revision to Military Standard 1474 (MIL-STD-1474): Design Criteria—Noise Limits. Through the efforts of a DoD multi-service working group, every aspect of MIL-STD-1474 has been revised to improve readability; reduce conflicting guidance; and consolidate requirements common to steady-state and impulsive noise produced by weapons systems, and ground-, air- and water-borne platforms. Noise requirements in military environments differ significantly from typical industrial or occupational situations, and mission success requires offensive equipment and weapons to be more lethal and survivable than those used by the adversary. Producing material suitable for military operations requires unique design criteria often exceeding civilian national or international standards. MIL-STD-1474E provides the design tools and measurement techniques necessary to satisfy these unique and often contradictory requirements. For the first time in MIL-STD-1474E, a computer-based, electro-acoustic model of the human auditory system is used to evaluate hazard from impulsive noise events typical of weapon firing. This presentation describes the salient requirements necessary to produce and deploy military systems maximizing Warfighter effectiveness, while minimizing hearing damage caused by their use.
Demonstrating compliance of noise exposure experienced by British military aircrew with noise legislation in the United Kingdom
Authors: James Susan H.
Published: October 2015

In 2005, the Control of Noise at Work Regulations were introduced into UK law and imposed two Exposure Limits Values, one for continuous noise and one for impulse noise. The Ministry of Defence (MOD) has mandated that the legislation will apply in full throughout the military, and hence, there has been a requirement to understand the types of exposure military operators are exposed to. Military aircrew have historically been exposed to high levels of continuous noise and the more stringent legislation has necessitated enhanced noise mitigation, including the development of new hearing protection technologies. However, in more recent years, military aircrew have become increasingly exposed to weapon firing and the MOD are now addressing the implications of the combined effects of the two different exposures and their impact on compliance with the legislation. In-flight measurement of continuous and impulse noise exposure has been conducted in a range of aircraft and the two exposures assessed for compliance with the legislative criteria. To meet the protection requirements in all platforms, enhanced hearing protection technologies are being developed, including Adaptive Digital Active Noise Reduction and comms processing techniques.
Noise exposure criteria for continuous noise: A case for reducing the 8 hour open ear exposure level
Authors: Gallagher Hilary , McKinley Richard L. , Theis Melissa A. , McKenna Elizabeth A.
Published: October 2015

Personnel working in hazardous noise environments can be protected from noise induced hearing loss (NIHL) or other hearing related disabilities when their exposures are limited. Limiting noise exposures can be accomplished by engineering controls, administrative controls, and/or with the use of personal protective equipment. Damage risk criteria (DRC) were developed as a guide to limit personnel noise exposure in order to reduce the risk of NIHL. With the exception of the US Occupational Safety and Health Administration (OSHA), the US and many European countries accepted the DRC of 85 dB for 8 hours with a 3 dB per doubling exchange rate. Recent studies of the auditory response to noise dose, conducted at the Air Force Research Laboratory, found that A-weighted open ear exposures may be more hazardous (i.e., have a higher effective noise dose) than equal A-weighted level protected ear exposures. A potential conclusion of these studies is that hearing protectors are more effective than previously thought and reducing the open ear exposure criteria may be needed in order to minimize NIHL. This presentation will describe the pros and cons of reducing the 85 dBA DRC.
Variations in elastic and anelastic properties as indicators of static and dynamic strain relaxation phenomena associated with phase transitions
Authors: Carpenter Michael A.
Published: October 2015

Almost all phase transitions are accompanied by some degree of lattice strain, typically varying between a few per mil to a few per cent, but extending to 5–10% for martensitic transitions. It is inevitable, therefore, that there will also be changes in elastic properties and, because the elastic moduli are susceptibilities, these are typically in the range of 10’s of per cent. At the same time, the associated transformation microstructures may be mobile under the action of external stress and therefore give rise to anelastic losses in a dynamical mechanical measurement. It has turned out that Resonant Ultrasound Spectroscopy, in a frequency window ∼0.1–2 MHz, is a particularly powerful method for characterizing elastic and anelastic behavior as functions of temperature and magnetic field for ferroic and multiferroic phase transitions in a wide range of materials. Examples of recent collaborative studies, relating to magnetoelastic effects in EuTiO3, multiferroic transitions in Pb(Fe0.5Nb0.5)O3, the influence of grain size on Jahn-Teller × charge ordering in La0.5Ca0.5MnO3, ferroelectric and ferroelastic transitions in metal organic frameworks, and martensitic transitions in Heusler alloys, will be used to demonstrate specific mechanisms and kinetics of static and dynamic strain relaxation phenomena.
Structural and magnetic phase transitions in EuTi1-xNbxO3: A resonant ultrasound spectroscopy study
Authors: Li Ling , Morris James R. , Koehler Michael R. , Dun Zhiling , Zhou Haidong , Yan Jiaqiang , Mandrus David G. , Keppens Veerle M.
Published: October 2015

We have investigated the structural and magnetic phase transitions in EuTi1-xNbxO3 (0 ≤ x ≤ 0.3) with synchrotron powder X-ray diffraction (XRD), resonant ultrasound spectroscopy (RUS), and magnetization measurements. The Pm-3m ↔ I4/mcm structural transition in pure and doped compounds is marked by a pronounced step-like softening of the elastic moduli near TS, which resembles that of SrTiO3 and can be adequately modeled using the Landau free energy model employing the same coupling between strain and octahedral tilting order parameter as previously used to model SrTiO3. Upon Nb doping, the cubic-to-tetragonal structural transition shifts to higher temperatures and the room temperature lattice parameter increases while the magnitude of the octahedral tilting decreases. In addition, Nb substitution for Ti destabilizes the antiferromagnetic ground state of the parent compound and long range ferromagnetic order is observed in the samples with x ≥ 0.1.
Simple homodyne ultrasound interferometer for solid state physical acoustics
Authors: Svitelskiy Oleksiy , Lee David , Grossmann John , Boatner Lynn A. , Yong Grace J. , Suslov Alexey
Published: October 2015

Ultrasonic pulse-echo technique is a valuable and non-destructive tool to explore elastic properties of materials. We propose a new instrument based on mass-produced microchips. In our design, the signal is processed by an AD8302 RF gain and phase detector (www.analog.com). Its phase output is linearly proportional to the phase difference between the exciting and response signals. The gain output is proportional to the log of the ratio of amplitudes of the received to the exciting signals. To exclude the non-linear fragments and to enable exploring large phase changes, we employ a parallel connection of two detectors, fed by in-phase and quadrature reference signals, respectively. The interferometer was tested by measuring the temperature dependences of both sound speed and attenuation in metallic glasses as well as in ferroelectric KTaNbO3 (KTN) single crystals. The instrument allows for exploring phase transitions with precision of ΔV/V ∼ 10−7 (V is ultrasound speed) in the broad dynamic range from −60 to × 20 dBm. These qualities allowed us to detect the theoretically predicted, but not observed previously velocity kink at the KTN phase transition from tetragonal to orthorhombic symmetry, whereas the attenuation curve showed new features in the development of the low-temperature structure of the KTN crystal.
Acousto-optic investigation of acoustic anisotropy in paratellurite crystals
Authors: Akhmedzhanov Farkhad R. , Saidvaliev Ulugbek
Published: October 2015

Propagation velocity and attenuation coefficient of acoustics waves in paratellurite crystals were measured by Bragg diffraction of light in the frequency range of 0.4–1.6 GHz. These results were used for calculation of real and imaginary components of the complex tensor of elastic constants. The analysis of the anisotropy of attenuation was carried out for the acoustic waves of different polarization propagating in the crystallographic planes, which are orthogonal to symmetry axes of second and forth order. The strongest anisotropy of acoustic attenuation and phase velocity is observed for the transverse acoustic waves propagating in the plane (1-10). It is shown that the attenuation reduces the integral efficiency of diffraction in several times in the acousto-optic deflector in which is used an oblique cut of paratellurite and the transverse acoustic wave propagating at an angle of 6 degrees to the [110] axis in the plane (1-10).
Vibrational and acoustic consequences of changes in subglottal pressure, vocal fold stiffness, vocal fold approximation, and vocal fold thickness
Authors: Zhang Zhaoyan
Published: October 2015

Using a three-dimensional continuum model of phonation, this study investigates the effects of changes in subglottal pressure, vocal fold approximation and stiffening, and vocal fold medial surface thickness on vocal fold vibration and acoustics. The results show that increasing subglottal pressure leads to more or less uniform increase in harmonic energy across a very large frequency range as well as significant increase in noise production. Reduced noise production can be achieved by increasing medial surface thickness, vocal fold approximation, or vocal fold stiffening. Increasing vocal fold thickness and stiffness also lead to increased production of high-frequency harmonics. The closed quotient of vocal fold vibration depends primarily on the medial surface thickness of the vocal fold, with the closed quotient increasing with increasing thickness. The closed quotient also slightly decreases with increasing subglottal pressure, but increases with increasing vocal fold approximation and stiffening. These results suggest that, in addition to increasing subglottal pressure, vocal loudness can be also increased by increasing vocal fold thickness, approximation and/or stiffening to increase production of higher-order harmonics and reduce noise production, which leads to a perceived increase in vocal intensity. [Work supported by NIH.]
Behavioral and computational estimates of breathiness and roughness over a wide range of dysphonic severity
Authors: Eddins David A. , Vera-Rodriguez Arianna , Skowronski Mark D. , Shrivastav Rahul
Published: October 2015

Perceptual evaluations of dysphonic voices frequently involve evaluation of the breathy and rough qualities. It is important to know how well one can disambiguate such VQ percepts in a perceptual evaluation so that accurate assessments can be made, focused treatment targets can be set, and outcomes can be quantified. In this study, 10 voices that varied over a wide range of breathiness and 10 voices that varied over wide range in roughness were selected from the University of Florida Disordered Voice Database (UFDVD). A single-variable matching task designed specifically for breathiness or roughness evaluation was used to index the perceived breathiness and roughness of the set of 20 stimuli. Because computational estimates of pitch salience (pitch strength) have been strongly associated with perceived breathiness, we also included a perceptual evaluation of pitch strength using an anchored magnitude estimation task. In an effort to better understand the interactions among perceived roughness and breathiness, a series of computational algorithms was used to estimate perceived breathiness and perceived roughness. Together, these results will help us understand the natural covariance of voice qualities and the ability to evaluate separate voice qualities independently.
The acoustics of perceived creaky voice in American English
Authors: Khan Sameer ud Dowla , Becker Kara , Zimman Lal
Published: October 2015

We compared auditory impressions of creaky voice in English to acoustic measures identified as correlates of contrastive voice qualities in other languages (e.g., Khmer, Chong, Zapotec, Gujarati, Hmong, Trique, and Yi). Sixteen trained linguistics undergraduates listened to the IP-final word ‘bows’ produced five times each by five American English speakers reading the Rainbow Passage, and gave a rating from 0 (no creak) to 5 (very creaky). Results show that stronger auditory impressions of creak are significantly correlated with lower f0, lower cepstral peak prominence (CPP), lower harmonics-to-noise ratios (HNR), and higher subharmonics-to-harmonics ratio (SHR). This suggests that listeners perceive greater creakiness as the voice becomes lower pitched, less periodic, and more audibly interspersed with subharmonic frequencies (i.e., diplophonia). Notably, none of the spectral amplitude measures proposed as acoustic correlates of glottal configurations for creaky voice in other languages (e.g., lower H1-H2 for smaller open quotient, lower H1-A1 for smaller posterior aperture, lower H1-A3 for more abrupt closure, etc.) was significantly correlated with these judgments in any expected direction. Taken together, these results suggest that while listeners consistently use pitch and periodicity as cues to creak, speakers might be varying in their articulatory strategies to achieve those acoustic effects.
Speech perception capabilities in children several years after initial diagnosis of auditory processing disorders
Authors: Crum Rachel , Padilla Jennifer , Morlet Thierry , Greenwood L. A. , Loson Jessica , Zavala Sarah , Nagao Kyoko
Published: October 2015

This study focuses on the progress of speech perception capabilities in children with auditory processing disorder (APD) measured several years after the initial diagnosis. A recent longitudinal study showed listening and communication difficulties of children diagnosed with APD persist into adulthood (Del Zoppo, Sanchez, and Lind, 2015). In the current study, we examined the speech perception progress of 21 children selected from the Auditory Processing Disorder database of 255 school-aged children in the Mid-Atlantic region as having an initial diagnosis of APD and an APD reassessment at our facility several years later. Average age for initial assessment was 7.9 (7–10) years with the most recent APD evaluation ages 11.5 (9–16) years. Results show that 81% of the children still had auditory processing deficits in their most recent evaluations, 9% had only associated area issues, and 10% exhibited typical auditory processing performance. We found that average standardized scores for all tests, except auditory figure ground, collectively increased in the second assessment. These tests include: competing words, competing sentences, filtered words, composite scores, and phonemic synthesis. While the auditory processing skills of some children with APD are improving over time, some children still show impairment in several processing areas.
Adults' perceptual voicing boundaries of 2-year-olds' citation form speech
Authors: Hitchcock Elaine R. , Koenig Laura L.
Published: October 2015

One way that speakers distinguish between phonemic categories is through voicing, frequently measured using voice onset time (VOT). Much perceptual research on voicing identification and discrimination has used synthetic speech stimuli varying in VOT. Results from adult listeners typically show stable crossover regions in the 20–35 ms range. Subsequent work, however, reveals that listeners' VOT boundaries vary with speech rate; further, an extensive history of research into vowel perception indicates that listeners normalize across vocal tract sizes. These considerations lead to the possibility that adult voicing boundaries may differ between the speech of adults vs. children, since children have slower speech rates and smaller vocal tracts. The present study obtained adult discrimination data for natural productions of bilabial and alveolar cognate pairs produced by 2–3-year-old monolingual, English-speaking children. Randomized stimuli were presented twice to 20 listeners resulting in 4,000 rated stimuli per category. The findings show 50% crossover points for VOT values at 28 ms for bilabials and 32 ms for alveolar phonemes. Such outcomes are consistent with past work based on adult data and suggest that mature listeners do not use substantially different perceptual criteria for judging voicing in children’s speech. Declaration of Interest Statement The authors have no financial or nonfinancial disclosures to report.
Speaker identification using auditory modeling and vector quantization
Authors: Iliadi Konstantina , Bleeck Stefan
Published: October 2015

Speaker identification (SID) aims to identify the underlying speaker(s) given a speech utterance. SID systems can perform well under matched training and test conditions but their performance degrades significantly because of the mismatch caused by background noise in real-world environments. Achieving robustness to the SID systems depends very much on the front-end (or feature extractor), which is the first component in an automatic speaker recognition system. Feature extraction transforms the speech signal into a compact representation that is more discriminative than the original signal. We present on our poster a new system where the parametrization of the speech is based on an auditory model called Auditory Image Model (AIM). Two experiments were performed for two different sets of speakers. Experiment 1 identified the most informative regions of the auditory image that can indicate speaker recognition. Experiment 2 consisted of training 10 and 60 speakers using clean speech and testing those two groups using speech in the presence of babble noise of eight speakers for 5 SNRs. The results suggest that the extracted auditory feature vectors led to much better performance, i.e., higher SID accuracy, compared to the MFCC-based recognition system especially for low SNRs.
Links between the perception of speaker age and sex in children's voices
Authors: Assmann Peter F. , Kapolowicz Michelle R. , Massey David A. , Barreda Santiago , Nearey Terrance M.
Published: October 2015

At a recent meeting [Assmann et al., J. Acoust. Soc. Am. 135, 2424 (2014)] we reported two experiments on the perception of speaker age and sex in children's voices, along with two models to predict listeners’ judgments. The stimuli were vocoded /hVd/ syllables produced by 140 speakers, ages 5 through 18, processed to simulate a change in the sex of the speaker. Experimental conditions involved swapping the fundamental frequency (F0) contour and/or the formant frequencies (FF) to the opposite-sex average within each age group. The present study extended the original experiments by requiring each listener to judge both age and sex on each trial to investigate the relationship between the two perceptual responses. Results revealed that age estimation error is systematically linked to sex misclassification, particularly in older children. In the unswapped condition, age estimates tended to be lower if the voice was identified as male, relative to the same voice heard as female. The condition with both F0 and FF swapped approached the opposite pattern of results; however, the remaining discrepancy indicates these are not the only cues for the perception of age and sex in children’s voices.
Listener characteristics and the perception of speech in noise
Authors: Silbert Noah , Motlagh Zadeh Lina
Published: October 2015

Speech communication is often made difficult by the presence of background noise. Much research on the perception of noise-masked speech has focused on the masking of phonetic information by different types of noise (e.g., white noise, speech-shaped noise, temporally modulated noise, multi-talker babble). The present work focuses on the relationships between some cognitive characteristics of listeners and accuracy in the identification of noise-masked consonants. 37 listeners identified numerous tokens of each of 4 consonants (p, b, f, v) in CV syllables produced by 8 talkers (4 male, 4 female) masked by 10-talker babble. Listeners also completed a number of tasks designed to measure selective attention: two dichotic listening tasks and two non-speech discrimination tasks. On each trial of the dichotic listening tasks, one or the other ear was cued visually (i.e., “right ear” or “left ear”), after which the listener indicated the talker sex or the consonant in the target ear, depending on task. In the two non-speech tasks, listeners discriminated either the frequency or the duration of broadband target noise bursts embedded in temporally modulated background noise. Analyses indicate a positive relationship between noise-masked speech accuracy and performance on the dichotic consonant identification and complex non-speech discrimination tasks.
Directivities of musical instruments that relate to their effects in performance environments and room simulations
Authors: Kirkegaard Larry
Published: October 2015

This paper addresses the particular aspects of Directivities of Musical Instruments that relate to “Their Effects in Performance Environments and Room Simulations.” Large ensemble—small ensemble—soloist Flat floor—raked floor—risers—steep risers Wrap of the ensemble Relation to Soloists Amplified or acoustic Seated vs. Standing Effects for performers and effects for Audiences with various audience configurations. This paper is meant to be a celebration of new techniques combined with cautionary tales that speak to needs for “measuring equipment” that includes experienced ears and questioning minds engaged in designing the testing techniques and evaluating their results to extract the most pertinent and applicable information.