bluuebunny/crossref_metadata_2025 huggingface dataset:
Speech coherence index with real speech and reverberation
Authors: Szuts Tobi A. , Schwenke Roger W.
Published: June 2017

Speech Coherence Index (SCI) is a proposed method of estimating speech intelligibility in real time with program material. The coherence of the complex valued transfer function is used to estimate the signal-to-noise ratio on a per frequency basis. The transfer function is calculated using short time windows at high frequencies and longer time windows at low frequencies to mimic the multi-resolution nature of human hearing. SCI has been shown to produce identical results to Speech Transmission Index (STI) in the case of pure noise interference. Like STI, SCI has been shown to decrease with a single reflection at longer latencies or at greater magnitude. SCI always decreases monotonically with single reflection latency, whereas STI varies up and down at extremely long latencies. For simulated reverberation, both STI and SCI have been shown to decrease with increasing reverberation time and reverberant level. However, SCI is more sensitive to direct-to-reverberant level. This paper will compare SCI to STI under more realistic conditions, such as speech signals and real-world impulse responses. The effect of signal crest factor will also be examined.
Simulation of acoustic environments—Part 1: Computer models
Authors: Vorlaender Michael
Published: June 2017

Simulation and auralization techniques are established in applications of room acoustics for quite a while. Research projects are currently focusing on a coordinated effort to improve the complete signal chain from the numerical modeling, the data acquisition within numerical or real sound fields, the coding and transmission to the electro-acoustic reproduction by binaural technology or by sound field synthesis. Approaches for the comparative evaluation of real and simulated environments will enable the evaluation of the plausibility and/or the authenticity of virtual acoustic environments. The state of the art is revisited and discussed along the series of the three past “round robins on room acoustic computer simulation.”
Simulation of acoustic environments—Part 2: Can we trust the computer?
Authors: Vorlaender Michael
Published: June 2017

The lessons learned from the “round robins” are that the main bottlenecks in room acoustic computer simulations are lack of data of 3D characterization of sound sources and material parameters, and interfaces to spatial audio technology. This presentation focuses on sources of uncertainties in such computer models and on the challenges in solving indoor acoustic problems. Also, a new initiative towards a fourth “round robin” on auralization is presented, which will be further elaborated in other papers of the special session.
Auralizations with loudspeaker arrays from a phased combination of the image source method and acoustical radiosity
Authors: Marbjerg Gerd , Brunskog Jonas , Jeong Cheol Ho , Zapata-Rodriguez Valentina
Published: June 2017

In order to create a simulation tool that is well-suited for small rooms with low diffusion and highly absorbing ceilings, a new room acoustic simulation tool has been developed that combines a phased version of the image source with acoustical radiosity and that considers the angle dependence of the surface properties. The new tool is denoted PARISM, and here PARISM is used to create loudspeaker array-based auralizations. Different auralization techniques are compared, such as Ambisonics, vector-based panning, and the method of nearest loudspeaker. The implementations of the auralization techniques with PARISM are described and compared to implementations of auralizations with another geometrical acoustic simulation tool, i.e., ODEON and the LoRA toolbox that applies Ambisonics to ODEON simulations. In opposition to the LoRA toolbox, higher order Ambisonics are also applied to the late part of the PARISM impulse response, because more directional information is available with acoustical radiosity. Small rooms with absorbing surfaces are tested, because this is the room type that PARISM is particularly useful for.
Effects of two different modeling alternatives of diffusive surfaces on the objective and perceptual evaluation of the simulated sound fields
Authors: Shtrepi Louena , Astolfi Arianna , Puglisi Giuseppina E. , Masoero Marco C.
Published: June 2017

Different acoustic simulation software have been substantially improved over the last decades accounting for absorptive and diffusive acoustic properties of different surfaces. Whereas the characteristics of the absorptive surfaces have been thoroughly investigated and implemented, the diffusive surface features are still subject to continuous research. So far, the degree of modeling detail of diffusive surfaces, and consequently, the effects that this has on the objective and subjective accuracy of simulations is an open point. In order to give more insight on this aspect, Odeon acoustic simulations have been performed in the model of a variable-acoustic concert hall using a diffusive and a reflective condition of one of the lateral walls. Two different modeling alternatives of the wall diffusive condition have been investigated. Objective acoustic parameters, such as early decay time (EDT), reverberation time (T30), clarity (C80), definition (D50), and interaural cross correlation (IACC), have been compared between the two conditions. Furthermore, a subjective investigation has been performed in order to determine the most accurate modeling alternative of the diffusive surfaces. Although the simulated objective results showed a good match with measured values, the subjective results highlighted significant perceptual differences for different modeling alternatives.
Using color mapping of sound intensity measurement to detect and identify sound isolation weak spots
Authors: Latour Jean-François
Published: June 2017

Typically, the ears of a trained acoustician could easily detect and identify the weakest element of a construction system when performing a sound isolation measurement. This typical approach to identify the path that needs to be addressed in order to increase sound isolation performance is however subjective. Because of this subjectiveness, this approach is sometimes challenged by skeptics and those that have a limited knowledge of acoustics. In those situations, a more objective approach and a better communication tool is required. For that purpose, a simple gridded sound intensity measurements combined with a color mapping algorithm is a powerful tool to illustrate the sound isolation weak spots. Examples are presented in order to show how sound isolation deficiencies (or absence of it) could become visually appreciated by building designers, constructors and managers with the use of sound intensity color mapping.
Comparative analysis of reverberation time methodology in residential applications
Authors: Watrous Jacob , Harkin Sean , Schnitta Bonnie
Published: June 2017

Impulsive sounds, such as balloon pops or the slapping of wood boards, are utilized by acoustical consultants in order to measure the reverberation time (T60) for residential applications with room volumes typically less than 150 cubic meters. However, these methods are not approved for measurement of the T60 for utilization in ASTM E336 ASTC and E1007 AIIC testing commonly practiced. Instead, the ASTM measurement of T60 requires a large loudspeaker and gated noise in order to gain performance in the low frequencies. Utilizing gated noise requires additional equipment to be carried in the field for AIIC and general T60 testing, making it a less attractive option for acoustical consultants. This paper compares T60 data collected utilizing various signal sources such as gated noise, balloon pops, and wood slaps at various source and receiving locations in rooms of varying volumes in order to compare the performance of various T60 measurement methods for use in ASTC and AIIC testing.
Understanding what the fish ear tells the fish brain
Authors: Edds-Walton Peggy L.
Published: June 2017

A. N. Popper (1977, 1981) described the organization of sensory hair cells on the otolithic endorgans of closely related and taxonomically distant fishes and stimulated decades of research on the functional significance of the great diversity that he observed. Comparative physiological studies (many featured in the reviews found in SHAR volumes edited by Popper and Fay, published by Springer-Verlag beginning in 1992) have revealed that auditory processing in fishes has much in common with hearing in other vertebrates. In addition, Arthur Popper, his collaborators, and his students have documented that the auditory information encoded by the ear provides the fish with sensitivity to sound frequency, level, and source direction. Specific examples will be provided. Popper also has been instrumental in educating the public, a Pulitzer Prize winning columnist (Dave Barry), and environmental regulators about fish hearing, most importantly, conveying the message that understanding hearing and the role of sound in the normal behavior of fishes is necessary for the conservation of marine and freshwater ecosystems.
Vertebrate ground plan for the evolution of vocal-acoustic communication
Authors: Bass Andrew
Published: June 2017

A central goal of comparative and evolutionary neurobiology is to establish how phenotypic variation in neuronal phenotypes translates into naturally selected diversity in behavioral performance. In this context, can we establish how the vocal-acoustic phenotypes of tetrapods were built over evolutionary time by identifying behavioral, anatomical, and physiological characters in sound producing/vocal fish? Studies of teleost fish, in particular, now provide a comprehensive investigation of the behavioral, neural, and hormonal mechanisms of acoustic communication in a vocal vertebrate at multiple levels of biological organization. Using “champion species,” this presentation will discuss the extent to which the collective evidence supports the hypothesis that three vocal-acoustic character states are shared between highly vocal species of teleost fish and tetrapods—vocal motor patterning and sequencing, vocal-auditory coupling, social context-dependent modulation by hormones. [Research support from NSF (IOS 1457108).]
Passive acoustic monitoring of haddock in the Gulf of Maine
Authors: Rountree Rodney A. , Burchard Katie A. , Mouy Xavier , Goudey Clifford A. , Juanes Francis
Published: June 2017

We have conducted several studies of haddock sounds in the Gulf of Maine (GOM) with mixed results. An analysis of an archival recording from captive haddock brood stock made in 1970 found that the “spawning rumble” sound occurred variously at the end of short thump trains, in the middle of thump trains, or in isolation. Interestingly, haddock were silent while spawning when we attempted to record sounds in the same facility in March 2000, suggesting that sound production may be negatively affected by chronic noise. Haddock sounds were absent in ROV and tethered instrument surveys in the summer and fall of 2001-2002. During 2006-2007, we deployed bottom mounted recorders while conducting long-line surveys of haddock spawning condition. Surprisingly few haddock sounds were detected and there was no correlation with spawning activity despite recording in highly active spawning areas. Haddock sounds consisted of isolated knocks, which were difficult to distinguish from thumps of unknown origin. We are now applying autodetection algorithms tuned to these data sets to extensive recordings made on the fishing grounds in 2003-2004. Our observations suggest that GOM haddock spawn in small isolated groups within a larger spawning area and their sounds are detectable only over short distances.
Revisions to the sound exposure guidelines for fish and sea turtles report
Authors: Halvorsen Michele B. , Popper Arthur N. , Hawkins Anthony D. , Mann David , Carlson Thomas J.
Published: June 2017

Anthropogenic underwater sounds can impact aquatic life. Adherence to the Marine Mammal Protection Act (MMPA), the Endangered Species Act (ESA), and the Magnuson-Stevens Fishery Conservation and Management Act (MSA) requires a risk assessment of the potential effects from underwater noise. Procedures for evaluating the risk to marine mammals (MMPA) are increasingly sophisticated, and quantitative science-based criteria for mammals were published in 2007 by Southall et al. The need for equivalent criteria for fishes and sea turtles (ESA and MSA) led to the creation of our expert working group co-led by Professors Arthur Popper and Richard Fay, pillars in the USA for everything fish. While Professor Tony Hawkins, a pillar in the EU for everything fish, brought his own unique perspectives and broad expertise of fish hearing studies and sound exposure. The results from our working group are described from its inception in 2004 to the 2014 publication of its findings as an ANSI/ASA report. The report determined broad sound exposure guidance based on the best available scientific information for fishes and sea turtles in a series of tables specific to a sound source. It is important to maintain current information and portions of the tables have recently been revised.
Ed Carstensen—Elucidating the physical mechanisms for biological effects of ultrasound
Authors: Dalecki Diane
Published: June 2017

Ed Carstensen was a pioneer in the field of biomedical ultrasound, and his ground-breaking research set the foundation for our understanding of physical mechanisms for the interaction of ultrasound with biological tissues and systems. In this presentation, I share my perspectives on Ed’s research advances from my viewpoint as his past student and research colleague for many years at the University of Rochester. Trained as a physicist, Ed focused on elucidating the physical mechanisms for biological effects of ultrasound. His early work identified ultrasound absorption mechanisms in blood, and later work studied effects of heating, cavitation, radiation force, and shear force on biological tissues. Ed’s research provided a basis for safety guidance of diagnostic ultrasound imaging, and for the development of new ultrasound therapies that exploit the physical interaction of ultrasound fields with tissues. Ed was a wonderful teacher and mentor who generously shared his time and insight. His leadership in the development of biomedical engineering and the founding of the Rochester Center for Biomedical Ultrasound have had lasting impact. Through his research and personal interactions, Ed positively influenced many in the field nationally and internationally, and set paths for the advancement of new applications of biomedical ultrasound.
The role of cavitation in vascular occlusion
Authors: ter Haar Gail , Rivens Ian , Civale John , Shaw Caroline , Giussani Dino , Lees Christoph
Published: June 2017

Ed Carstensen’s papers on the effects of ultrasound on plants were amongst the first that attracted me to study ultrasound bio-effects. It was little surprise to me that, when I first started looking at HIFU, his name was on many of the seminal papers in this area. And now, his papers on cavitation and vasculature inform our current research. Ed’s influence on bio-effects research stretches far beyond the borders of the USA Vascular occlusion has the potential to treat life-threatening conditions including twin-twin transfusion syndrome (occurring in fetuses that share a placenta). Sheep placental vessels have been used to develop HIFU treatment guidance, delivery (1.66MHz) and monitoring. Ultrasound imaging guidance/flow monitoring, with simultaneous acoustic cavitation detection in 82 targets in 14 pregnant sheep resulted in flow occlusion in 90%. Adverse events included skin erythema (18/82) and burns (10/82), but all resolved over 21 days. Analysis of acoustic cavitation required low pass (software) filtering and careful choice of broadband integration range (0.1 to 1.1 MHz). 9% of successful treatments displayed detectable broadband, 32% with half-harmonic and 1% with drive-voltage fluctuations. In conclusion, treatment is possible, side effects are manageable, and acoustic cavitation appears not to be essential for successful occlusion.
Characterization of micro-perforated panel at high sound pressure levels using rigid frame porous models
Authors: Laly Zacharie , Atalla Noureddine , Meslioui Sid-Ali
Published: June 2017

An acoustic impedance model to predict the acoustic response of micro-perforated panels at high sound pressure levels is proposed using rigid frame porous models. The micro-perforated panel is modeled following Johnson-Allard approach with an effective density which depends on the frequency. The incident sound pressure on the surface of the perforations is considered as a main variable in the model and the parameters of the equivalent fluid such as the tortuosity and the flow resistivity are expressed as functions of this incidence pressure. The proposed model shows good agreement by comparison with other existing nonlinear impedance models for sound pressure level up to 150 dB. Experimental measurements were performed on several micro-perforated panels backed by air cavities using an impedance tube equipped with a high sound speaker capable of delivering a high sound pressure level up to 155 dB. A good correlation between theoretical and experimental results is obtained. Micro-perforated panel backed by porous layer is modeled and validated experimentally using an equivalent tortuosity of the micro-perforated panel which depends on the dynamic tortuosity of the porous layer.
Investigation of the impedance of a micro-perforated plate with two-sided grazing flow
Authors: Farooqui Maaz , Elnady Tamer , Åbom Mats
Published: June 2017

Acoustic impedance for perforates is mainly quantified by semi or totally empirical formulas, which depend on the experimental set-up used and are specific for each type of tested sample. In this work, the acoustic impedance of a micro-perforated plate (MPP) with two-sided low Mach grazing flow is educed by a modified semi-analytical inverse technique. The inputs to this technique are complex acoustic pressure measured at eight positions at the wall of the duct, upstream and downstream of the MPP section. Several measurements on the two sided grazing flow rig are conducted and trends in the impedance shift are observed. These trends serve to quantify the change in the resistance and reactance of a MPP when it is subjected to two sided grazing flow. An empirical formula is also proposed which is based on these trends. This formula helps in approximating the behavior of MPP’s in applications such as perforated cooling fans, perforated guide vanes, and turbine nozzles. It was observed that with increased flow velocity on either side of the duct the resistance tends to increase while the reactance drops.
Reducing the generation of discrete-tones by micro-perforating the back of an open shallow cavity under a subsonic flow
Authors: Maury Cédric , Bravo Teresa , Mazzoni Daniel , Amielh Muriel
Published: June 2017

An experimental and numerical study has been carried out to investigate the effect of micro-perforating the back of an open shallow cavity under a low-speed air flow in order to reduce the amplitudes of the discrete tones due to the shear layer-cavity interaction. Open shallow cavities with length-to-depth ratio of 10 and 17 have been considered flush-mounted on the test section of a low-speed wind-tunnel with mean flow velocity 30 m/s. The bottom plate of the cavity was either a plain or an unbacked micro-perforated panel (MPP). A set of wall-pressure measurements over the bottom wall showed that the MPP was able to reduce by up to 8 dB the amplitude of the discrete tones, mostly noticeable beneath the upstream edge of the cavity within the recirculation bubble where the acoustic components dominate over the broadband components. However, the MPP may enhance the broadband components over and beyond the reattachment zone, thereby suggesting to micro-perforate the back wall only in the attenuation zone. These results were assessed against aeroacoustic numerical simulations performed in time domain using Lattice Boltzmann Method. The effect of the cavity length-to-depth ratio on the damping induced by the micro-perforated treatment was also examined.
Phantom partials in the piano sound and the role of the soundboard
Authors: Rokni Eric , Adkison Camille , Moore Thomas
Published: June 2017

The presence of phantom partials in the spectra of the piano sound are well known, and for decades they have been attributed to forced longitudinal vibrations in the string. These vibrations are generally assumed to originate with the stretching of the string, which produces frequency components at the sums, differences and second harmonics of the resonant frequencies of the transverse string motion. Results of recent experiments indicate that phantom partials can be produced in other parts of the piano as well as the string, and in some cases these contributions to the sound can be significant. Measurements of the power in multiple phantom partials produced simultaneously by steady-state excitation are providing insight into the process that creates them.
Testing of urban road traffic noise annoyance models—based on psychoacoustic indices—using in situ socio-acoustic survey
Authors: Gille Laure-Anne , Marquis-Favre Catherine
Published: June 2017

Noise annoyance is one of the main non-acoustical effects of noise. To manage this environmental issue, European cities of more than 100,000 inhabitants produce strategic noise maps which represent the noise exposure in terms of Lden. Despite this index is used in dose-effect relationships, several studies showed that models based on Lden insufficiently predict annoyance measured during in situ survey. Indeed, several acoustical characteristics (e.g. temporal variation) influence noise annoyance and are not considered by Lden. Laboratory experiments enable to propose annoyance models based on noise sensitivity and several psychoacoustic indices. These indices enable to characterize different acoustical characteristics. However, they cannot be measured for each respondent during an in situ survey. It was therefore not possible to test these annoyance models using in situ survey data. Thus, a methodology is proposed to estimate the values of the psychoacoustic indices on the basis of Lden given in survey database. Urban road traffic noise annoyance models are tested using French survey data. Annoyance predicted by these models is compared to the measured one. Results show that these noise annoyance models coupled with the methodology to estimate the values of the different indices enable a better prediction than Lden only.
A review of transport noise management plans in large North American and European cities
Authors: Rice Julian , Steele Daniel , Dumoulin Romain , Guastavino Catherine
Published: June 2017

Noise management plans of large cities are diverse along many factors, such as the responsibilities amd interactions at different levels of governance (national vs. local) and definition of noise (measurement-reliant vs. subject-centered). More specifically, for the regulation of transportation noise, there are various ways these sources are identified (by source type or acoustic signal properties), managed (time of day, zoning, and context), and controlled (police v. specialized departments, complaint systems, treatment of private v. public sources). The regulations, official communications and plans for transport noise are analyzed for 20 major North American and European cities (> 500,000 inhabitants) in order to assess current noise management strategies. Over the past 15 years, an extensive body of academic literature has provided grounds for a soundscape approach to urban noise where “appropriate” sounds can be used to positive effect. Current management plans are also examined for existing applications of this soundscape approach. Results will assist in highlighting trends and will feed into the development of best practices for noise management and regulation in large cities. This review is part of a larger project (Sounds in the City), a collaborative research effort with the City of Montreal, to shape the future of urban noise management.
Effect of atmospheric stability and low level jets on wind turbine noise
Authors: COTTE Benjamin
Published: June 2017

Numerous studies from the literature have shown that strong wind shear occurs frequently in stable atmospheres, typically at night. This phenomenon can be associated to low level jets, characterized by a wind speed profile with a maximum at a few hundred meters above the ground. This study investigates the effect of such wind speed profiles on wind turbine noise using a physically-based model. The predictions are obtained by coupling an aeroacoustic source model based on Amiet’s theory and a parabolic equation code for acoustic propagation in an inhomogeneous atmosphere. Two important broadband noise generation mechanisms are considered, namely trailing edge noise and turbulence inflow noise, and the coupling method takes into account the fact that wind turbine blades are moving and extended sources. In order to obtain realistic wind speeds for the simulations, a simple model of nocturnal low-level jet is used, with input parameters based on measurements acquired in Cabauw observatory in the Netherlands. Predictions of the overall sound pressure levels and of the third octave band noise spectra will be presented up to a distance of 1km to show the noise variations due to the wind shear effect.
A German-French acoustic road pavement database: DEUFRABASE latest version
Authors: Berengier Michel C. , Picaut Judicaël , Beguere Antoine , Fortin Nicolas , Pallas Marie-Agnes
Published: June 2017

The aim of this database developed during two DEUFRAKO (German/French cooperation) projects is to provide a tool to predict in a large number of predefined situations, the impact of road pavements on Lden estimation for realistic configurations in terms of geometry, traffic composition and propagation effects. The method implemented is based on (i) the standardized light and heavy vehicles LAmax measured according to ISO pass-by method, (ii) on the relationship between this LAmax and the single vehicle LAeq calculated on a 1-hour time period, (iii) on the excess sound attenuation between two receivers, one located in the road vicinity (7.50 m-1.20 m) and the other in farfield and (iv), on an average daily traffic distribution. In 2008, a first version of the database was implemented and uploaded on the German partner’s website. More recently, the database structure has been redesigned to easily add new configurations of topography, traffic and pavements. New indicators, representative for instance of urban constraints, could also be envisaged. The paper deals with the description and validation of the procedures implemented, including their accuracy estimation, the new open access website (deufrabase.ifsttar.fr) and how to use it for road traffic noise prediction.
Atmospheric turbulence effects on acoustic vector sensing
Authors: Collier Sandra L. , Solomon Latasha , Ligon David , Denis Max , Noble John , Alberts W. C. Kirkpatrick , Sim Leng
Published: June 2017

Acoustic vector sensing has been established in the underwater community, and is gaining interest in the atmospheric community as technologies continue to improve. The effects of atmospheric turbulence on acoustic pressure-sensor arrays has been well studied and documented. Two-dimensional acoustic particle velocity and acoustic pressure, concurrent with atmospheric data, were collected during a series of field tests. Here, we examine the effects of atmospheric turbulence on acoustic vector sensing.
Hybrid Fourier pseudospectral/discontinuous Galerkin time-domain method for arbitrary boundary conditions
Authors: Pagán Muñoz Raúl , Hornikx Maarten
Published: June 2017

The wave-based Fourier Pseudospectral time-domain (Fourier-PSTD) method was shown to be an effective way of modeling outdoor acoustic propagation problems as described by the linearized Euler equations (LEE), but is limited to real-valued frequency independent boundary conditions and predominantly staircase-like boundary shapes. A hybrid modeling approach was recently presented to solve the LEE, coupling Fourier-PSTD with the nodal discontinuous Galerkin (DG) time domain method. The hybrid approach allows the computation of complex geometries by using the benefits of the DG methodology at the boundaries while keeping Fourier-PSTD in the bulk of the domain. This paper presents the implementation of arbitrary boundary conditions in the novel methodology, for instance, frequency dependent boundaries. The paper includes an application case of sound propagation for an urban scenario and the comparison of the numerical results with experimental data.
Characterizing composites with acoustic backscattering: Combining data driven and analytical methods
Authors: Gower Artur L. , Deakin Jonathan , Parnell William J. , Gower Robert M. , Abrahams Ian D.
Published: June 2017

Acoustic wave measurements are quick and non-invasive. They can be ideal to characterize composites, when we can accurately interpret the acoustic signals. However, for a wide range of frequencies, interpreting the signal is complicated as the field will be subjected to multiple scattering. We introduce a new data driven approach to characterize composites via acoustic backscattering. There are two major challenges in a data driven approach. First, we need a large amount of data of backscattered waves from well characterized composites. Second, is how best to use this data to characterize unknown composites. In this talk, we address both these challenges, and use simulated 2D data to demonstrate our method. Our methodology can be used to characterize many features of the medium in question, but for simplicity, we make a number of assumptions: the medium is formed from two materials; one material forms a large number of scatterers (all with approximately the same radius) embedded in a uniform background material. Characterizing this composite is now equivalent to measuring the volume fraction and radius of the scatterers. To simulate a wide range of volume fractions and scatterer sizes, we use the exact theory for acoustic scattering by identical circular cylinders.
Pitch magnitude estimation can predict across-ear pitch comparisons in cochlear-implant users
Authors: Anderson Sean R. , Kan Alan , Thakkar Tanvi D. , Litovsky Ruth
Published: June 2017

Bilateral cochlear implants provide auditory input in both ears, but sensitivity to interaural time differences (ITDs) varies across individuals. One factor affecting ITD sensitivity is place-of-stimulation mismatch across ears. Currently there is no fast method for estimating mismatch. Since pitch varies depending on place-of-stimulation, our laboratory uses two pitch-matching methods to estimate matched place-of-stimulation across ears: pitch magnitude estimation (PME) and direct pitch comparison (DPC). PME involves rating pitch from 1 (lowest) to 100 (highest) for even numbered electrodes in each ear. DPC involves comparing the pitch of one electrode against six electrodes in the opposite ear, yielding an estimate of place-of-stimulation mismatch at one electrode. DPC predicts interaural electrode pairs with good ITD sensitivity, but is relatively slow because pairs are chosen one at a time. PME is a much faster, global estimate of the relative difference of interaural electrodes, but it is uncertain whether PME can predict the same interaural pairs as DPC. Here, we predict DPC estimates from PME results using regression techniques. Results suggest PME may be an efficient tool for creating clinical maps that yield good binaural sensitivity. [Work supported by NIH-NIDCD R01-DC003083 to RYL, NIH-NIDCD R03-DC015321 to AK, and NIH-NICHD P30-HD03552 to Waisman Center.]
Factors associated with broad binaural pitch fusion in children and adults with hearing aids and cochlear implants
Authors: Reiss Lina , Hartling Curtis , Glickman Bess , Fowler Jennifer , Stark Gemaine , Oh Yonghee
Published: June 2017

Many hearing-impaired adults who use hearing aids (HAs) and/or cochlear implants (CIs) have broad binaural pitch fusion, such that sounds with large pitch differences are fused across ears (Reiss et al., JARO 2014; JASA). The goal was to determine which subject factors are associated with broad binaural pitch fusion. Binaural pitch fusion was measured in bilateral HA users, bimodal CI users who use a HA in the contralateral ear, and bilateral CI users. Fusion ranges were measured by simultaneous, dichotic presentation of reference and comparison stimuli in opposite ears, and varying the comparison stimulus to find the range that fused with the reference stimulus. Both children (ages 6-9) and adults were tested. Children in the HA and bilateral CI groups had broader fusion than the bimodal CI group. In addition, broad fusion was positively correlated with long durations of HA use and early onset of hearing loss in adult HA users, and negatively correlated with duration of CI use in pediatric bimodal CI users. No correlations with subject factors were seen in bilateral CI users. The findings suggest that type of hearing device experience may influence binaural pitch fusion in hearing-impaired individuals, especially children. [Work supported by NIH-NIDCD grant R01 DC013307.]
Stimulus features affecting speech recognition in a two-talker masker
Authors: Calandruccio Lauren , Buss Emily , Leibold Lori , Lowery Mary
Published: June 2017

Large individual differences in performance have been observed for speech recognition in the presence of two-talker speech maskers. Moreover, two-talker masker samples appear to vary in masking effectiveness. These two observations suggest that (1) listeners vary in the extent to which they take advantage of stimulus features that aid in the segregation of target from masker speech and (2) maskers vary in the extent to which salient stimulus features are available that aid in the segregation of target from masker speech. Stimulus talker variability and individual listener variability are explored across two experiments. The first experiment evaluates differences between talkers based on vocal characteristics. These characteristics include fundamental frequency, pitch variability, and cadence. Additionally, listeners are asked to rank each individual competing talker’s voice with respect to similarity to the target talker’s voice. The second experiment will explore linguistic differences in the competing speech including two-talker maskers that consist of concatenated sentences, story passages, and conversational dialogs and how the content of the speech affects masking. Data will be presented for listeners with normal-hearing thresholds.
Effect of relative envelope periodicity on speech-on-speech masking
Authors: Apoux Frederic , Carter Brittney , Healy Eric
Published: June 2017

Speech intelligibility generally increases as the difference in fundamental frequency (F0) between two simultaneous talkers increases. Vocoded speech shows no such effect. However, as previous work reported a contribution of envelope periodicity to masking release, an effect of F0 separation should be observed with vocoded speech. In a first experiment, the effect of F0 separation in vocoded speech was directly evaluated by presenting pairs of simultaneous sentences from the same male talker. The background sentence was time-reversed and its F0 was manipulated to range from 0 to 1 octave above that of the target sentence. Although limited, an effect was observed for large F0 separations. In a second experiment, target and background sentences were from different talkers and differed in envelope cutoff rates. The envelope low-pass cut-off of one signal was manipulated independently, ranging from 4 to 400 Hz, while the other was fixed at 400 Hz. As expected, decreasing the cut-off of the target resulted in a decrease in intelligibility. Inversely, decreasing the cut-off of the background improved intelligibility by as much as 50% points at 4 Hz. These findings show a potential contribution of envelope periodicity to speech-on-speech masking but only for very large F0 separations.
Linguistic contributions to frequency importance functions in children with normal hearing
Authors: McCreery Ryan W. , Bosen Adam K. , Brennan Marc A.
Published: June 2017

Frequency-importance functions represent the contribution of an individual frequency band to speech recognition and are used to generate weighted estimates of audibility in the Speech Intelligibility Index (SII). To date, nearly all frequency-importance functions have been derived from adult speech perception data. Estimates of audibility based on these functions are increasingly being applied to children who wear hearing aids. Frequency-importance functions based on perceptual data from children and adults do not differ on average (McCreery & Stelmachowicz, 2011), but importance functions derived from children are more variable than those obtained from adults. Numerous factors could influence individual variability in frequency-importance functions for children. The purpose of this study was to examine the influence of language abilities on individual differences in importance functions obtained from children. We hypothesized that children with stronger vocabulary knowledge would have importance-functions that were more adult-like than peers with more limited vocabulary abilities. Frequency-importance functions were derived from a group of 105 children with normal hearing who were between 5-12 years of age and a group of 20 adults with normal hearing. Children with higher vocabulary abilities had frequency-importance functions that were more adult-like than peers with lower vocabulary abilities, after controlling for age.
Relating verbal and non-verbal auditory spans to language comprehension performance
Authors: DiGiovanni Jeffrey J. , Riffle Travis L. , Weaver Aurora J.
Published: June 2017

Working memory capacity has often been assessed by various forms of the span task (e.g., reading span, digit span, etc.). Simple span tasks involve storage, whereas complex span tasks involve both storage and processing, and can include verbal and/or non-verbal stimuli. Arguably, daily activities, such as engaging in conversation or understanding a news article, require more storage and processing than recalling a list of numbers. The objective of this study was to determine the relationship of verbal and non-verbal auditory spans to language comprehension performance. Twenty-two normal-hearing adults participated in the study consisting of the following four experiments: forward and reverse digit span, Working Memory Span Task, Pitch Pattern Span Task, and the LISN (Lecture, Interview, and Spoken Narratives) listening comprehension task. Results revealed no significant relationship between non-verbal spans and language comprehension. Also, there was no significant relationship between forward and reverse digit spans to language comprehension. There was a significant correlation between the working memory span task and language comprehension. This suggests that complex language-based tasks that require more storage and processing will be better predictors of language comprehension than simple span tasks or tasks that do not involve language.
Sound source localization: 1850s to 1950s
Authors: Yost William
Published: June 2017

While scientists and philosophers have been interested in sound source localization since the time of the ancient Greeks, the modern study of this topic probably began in the late 19th century. Because sound has no spatial dimensions, there were many arguments at this time as to how humans localize a source based on the sound it produces. Lord Rayleigh conducted a “garden experiment” and concluded that a binaural ratio of sound level at each ear could account for his ability to identify the location of people who spoke in the garden. This type of experiment began the modern investigation of the acoustic cues used for sound source localization. In the first half of the 20th century, psychoacousticians such as Licklider, Jeffress, Mills, Newman, Rosenzweig, Stevens, von Hornbostel, Wallach, Wertheimer, and many others (documented by Boring in Sensation and Perception, 1942 and by Blauert in Spatial Hearing, 1997) added seminal papers leading to our current understanding of sound source localization. This presentation will briefly review some of this history. [Partially support by a grant from the National Institute on Deafness and Other Communication Disorders, NIDCD).]
The nature and import of the legacy of Binaural Hearing research from 1900 to 1950
Authors: Trahiotis Constantine , Bernstein Leslie R.
Published: June 2017

The goal is to present a historical picture of the research that serves as the foundations for Binaural Hearing as we know it today. The focus will be on the scientists and students who conducted that research and the institutions at which they resided. Knowledge composing the foundation of the field of binaural hearing is commonly identified with several individual pioneering scientists whose publications formed its basis. What is not so well appreciated is the fact that the modern literature stems from succeeding generations of doctoral and post-doctoral students that are related to the pioneers and each other via a rich set of integral institutional and personal interrelationships. In today's field of Binaural Hearing it has become commonplace to be trained by more than one mentor, in laboratories at more than one institution, in more than one discipline spanning anatomy, physiology, behavior, or acoustical engineering and, often, to perform mathematical modeling using information gleaned from any or all of them. Today, despite one's particular background, it is possible to be employed (often doing similar research) in any of a variety of settings within universities and industry. The primary motivation for this talk stems from interest expressed by many of our younger colleagues. Over many years, they have shown a delight in learning about “who trained and worked with whom, and where.”
Characterizing hidden and overt sensorineural hearing loss: Assays of peripheral pathophysiology and histopathology
Authors: Kujawa Sharon G.
Published: June 2017

The study of acquired sensorineural hearing loss (SNHL) has relied heavily on assessments of hair cell injury and loss and the threshold sensitivity losses that accompany them. This strategy is based on the view that, for most acquired SNHL etiologies, sensory hair cells are the most vulnerable cochlear elements and auditory neurons (ANs) degenerate if, and only long after, loss of their peripheral inner hair cell (IHC) targets. Recent work in our laboratories has suggested that, in aging and after noise, the synaptic connections between IHCs and ANs are actually the most vulnerable elements, and that massive cochlear synaptopathy can be seen before hair cell loss or threshold elevation. In characterizing these outcomes, our investigational algorithms have relied on assessments of hair cell and early-stage neural generators of evoked potentials, coupled with otoacoustic emissions, tests of middle ear and medial olivocochlear reflexes and electrophysiological assays of neural temporal fine structure processing. Responses recorded non-invasively facilitate translation of findings in the animal models to clinical diagnostics. We couple these with assessments of histopathology of hair cells, neurons and the synapses that connect them, which, at present, provide the only truly definitive assay for the synaptopathy. [Work supported by NIH/NIDCD, DoD, and ONR.]
Influence of behavioral state on auditory processing in the marmoset midbrain
Authors: David Stephen V. , Shaheen Luke A. , Slee Sean J.
Published: June 2017

Recent work shows that neurons in the inferior colliculus (IC) undergo receptive field changes during auditory behavior in ferrets (Slee & David, 2015. J. Neurosci.). In this study, we tested for similar effects in the marmoset monkey, a highly vocal primate species. We trained two marmosets to detect a pure tone target embedded in a background of random spectral shape (RSS) distractor stimuli. We recorded single-unit activity in the central nucleus of the IC (ICC). Neural responses to targets and distractors were compared between conditions when the marmoset performed the detection task or listened passively. When target frequency was near the neuronal best frequency (BF), responses to distractors were suppressed in about half of the neurons during behavior. Target responses were modulated in some neurons but suppression or enhancement was equally likely. We also measured effects of task engagement in non-central divisions of the IC (NCIC). There, target responses were strongly enhanced during behavior in about half of neurons in this region (median change = 70%). We also found a subset of NCIC neurons that responded with increased firing following the target sound, possibly encoding a reward-related signal. This study replicates our previous finding that distractor responses are suppressed during auditory behavior in the ferret IC. In addition, we found an area in the NCIC with large enhancement of target responses during behavior, suggesting that task engagement produces distinct effects across subdivisions of the IC.
Sustained periodic phase locking during a perceptual streaming task using resolved and unresolved harmonic tones
Authors: Ruggles Dorea , Tausend Alexis N. , Oxenham Andrew J.
Published: June 2017

Perceptual object formation and streaming are critical aspects of auditory processing. Previous studies have found cortical markers of streaming and attention, but it is unclear if these depend on tonotopic separation or whether other features, such as fundamental frequency (F0), are represented by these cortical markers. In this study, we used complex tones comprised of resolved or unresolved harmonics and simultaneously measured cortical and subcortical steady-state EEG responses during a behavioral streaming task. Subjects attended to either a fast stream of high-F0 harmonic complexes or a slower stream of lower-F0 complexes, filtered into the same spectral region. Subjects maintained directed attention during 1-minute blocks while reporting level oddballs in the attended stream and ignoring oddballs in the unattended stream. During the task, sustained envelope following responses phase locked to the complex F0 (nominally subcortical) and to the presentation rates (nominally cortical) were recorded. Phase-locking analyses suggest that directed attention does not alter subcortical sustained responses or cortical sustained responses to streams comprised of unresolved harmonics. Attentional effects in cortical responses to streams of resolved harmonics suggest that the cortical markers of attention and segregation reflect enhancement based on tonotopic segregation. [Work supported by NIH grants R01DC007657 and R01DC005216.]