bluuebunny/crossref_metadata_2025 huggingface dataset:
Subjective evaluation of community noise in Canada's National Capital Region and its relation to waking levels of salivary biomarkers.
Authors: Michaud David , Keith Stephen , Tsang Jason , Konkle Anne
Published: October 2013

Some research has suggested an association between long-term exposure to traffic noise and relative risk of cardiovascular disease (Babisch et al., 2005; Willich et al., 2006). It has been assumed that noise may act as a nonspecific stressor. Acute exposure to noise can evoke physiological and behavioral changes reminiscent of a stress response in rodents (Michaud et al., 2003), but it is equivocal that this occurs in humans chronically exposed to traffic noise. This pilot project examined annoyance to community noise and salivary biomarkers known to be influenced by stressor exposure. A face-to-face interview subjectively assessed community noise for 60 residents (30 males, 30 females; mean age 41.3, SD=14.98). Traffic sound levels will be determined and respondents categorized into high (>65 dBA, Leq24) and low (<50 dBA) noise areas. Participants also provided saliva samples upon awakening, 30 min after awakening, and prior to bedtime. Concentrations of salivary biomarkers of alpha-amylase and cortisol were spectrophotometrically determined using commercial enzyme-linked immunosorbant assays. Two-way (high-noise versus low-noise) mixed-model analyses of variance will examine differences in questionnaire and salivary responses. Sex differences will be evaluated with independent t-tests, and polynomial regression analyses will relate salivary biomarker levels to high- or low-noise areas.
Early studies of vibrational relaxation phenomena.
Authors: Shields F. Douglas
Published: October 2013

Bass received the Silver Medal in Physical Acoustics in 2006 in recognition for the prodigious amount of work he did, largely in the area of sound absorption in the atmosphere in 1971 and 1972. When he came to Ole Miss straight from graduate school in 1970, he was 27 years old with a wife and three children. He had worked his way through college while supporting his family and served a 2 year tour of active duty in the Signal Corp before entering graduate school. He continued his service in the Army Reserve and retired in 1993 with the rank of Lieutenant Colonel. During the first three years he was at Ole Miss, he published 17 refereed papers and gave 5 papers at ASA meetings. This talk traces the path his research followed during this period in moving from his dissertation study of rotational relaxation as a function of temperature in a series of polar polyatomic gases to the successful explanation of the variation of sound absorption in the atmosphere with humidity, temperature, and frequency. Also discussed are his experiments during this period with the spectraphone and his work with Hans Bauer in developing the theory for sound amplification from controlled excitation reactions (SACER).
Tornadoes, thunder, and underwater sound from lightning.
Authors: Atchley Anthony A.
Published: October 2013

Outdoor sound propagation was a cornerstone of Bass’ research throughout much of his career. During the late 1970s, propagation of sound from natural sources became of particular interest. This talk focuses on three aspects of this phase of Bass’ research: (1) efforts to localize lightning from an analysis of recordings made with a distributed ground microphone array, (2) recording the underwater sound produced by lightning striking the surface of the ocean, and (3) development of a tornado alert detector based on the acoustic signature of tornadoes.
The influence of Hank Bass on ground effect research between 1981 and 1995.
Authors: Attenborough Keith
Published: October 2013

In 1981 Bolen and Bass published a paper on ground effect, which included a pioneering effort to deduce ground impedance from propagation data. This study was a forerunner to recent work on the ANSI standard for measuring ground impedance. My first interaction with Bass in the same year stemmed from a mututal interest in observations of buried geophone responses to airborne sound sources. Our initial experiements involved understanding the response of buried microphones to airborne sound and the relationship of ground properties to the phenomenon of ground effect. Subsequently, work with Bass and colleagues inspired treatments of the ground as a layered poroelastic medium. As a result of Bass’ initiative, the first 12 Long Range Sound Propagation Symposia (LRSPS) was held in Mississippi. This helped to introduce researchers interested in atmospheric acoustics to the propagation codes used in underwater acoustics. The LRSPS initiative, together with Bass’ involvement with the NATO RSG11 study group, resulted in benchmarks for testing the various atmospheric propagation codes that were available in 1995.
Henry Bass’ contributions to the infrasound renaissance: Notes from the field.
Authors: Garces Milton
Published: October 2013

The deployment of the international monitoring system global infrasound network at the turn of the 21st century inspired a renaissance in innovation, development, and application of infrasound technology. In the United States, Hank Bass was responsible for defining and directing the scientific agenda, and he skillfully navigated the turbulent waters of national and international policy through a decade of administration changes. In addition, he created and nurtured a cohesive community of collaborating partners in academia, industry, and government. This presentation honors Hank’s contributions to the field of infrasound within the context of past, present, and future research efforts in the U.S. and abroad.
An acoustic comparison of nonlinguistic sounds to sentences spoken in American English.
Authors: Bickley Corine , Inverso Yell
Published: October 2013

Acoustic characteristics of nonlinguistic (nonspeech) sounds (NLSs) were measured for duration and spectral variation, and compared to acoustic characteristics of spoken sentences (TIMIT database). The NLS, included samples produced by animal, human, mechanical, and natural sources. The acoustic comparison examined stoplike onsets, fricativelike intervals, vowel-like intervals, and syllablelike variations in amplitude. The NLSs were identified by two groups of listeners: listeners with normal hearing and users of cochlear implants. Results of the listening tests have been reported previously by Inverso et al. (2007) and Inverso (2008). All of the NLSs were identified accurately by listeners with normal hearing, but not by the users of cochlear implants. The current analysis focuses on the ways in which the NLSs are similar to and other ways in which they are different from sentences spoken by a variety of talkers. It was found that speechlike variation in amplitude, both in terms of duration and event onset/offset, was a strong cue for listeners with cochlear implants; that is, NLSs that contained distinct events that were similar in duration and amplitude variation to syllables in speech were identified more accurately than ones that did not.
Acoustic discrimination and categorization of formant dynamics for novel and familiar stimuli.
Authors: Fogerty Daniel
Published: October 2013

Perception of a formant transition continuum from /b/ to /d/ was tested for a high-fidelity speech continuum and an analogous sinewave speech continuum. Endpoint stimuli were recorded by a male talker, matched for fundamental frequency and duration, and interpolated using a STRAIGHT morphing algorithm to produce a continuum of 11 steps. The first three formants were replaced with sinewaves to create a sinewave speech continuum. This study used a between-subject paradigm, which enabled comparison of highly familiar natural stimulus categories to novel sinewave stimulus categories while preserving fundamental acoustic cues for perception (the first three formants). Categorization training and discrimination blocks were interleaved during testing to track the effect of category learning on discrimination. Results for sinewave speech failed to demonstrate significant short-term category learning or a change in discrimination performance across three blocks. However, discrimination and categorization performance were fundamentally different between continua. While discrimination for natural speech was best near the category boundary, participants who heard sinewave speech appeared to use detailed differences in pattern dynamics, resulting in best discrimination near specific stimuli characteristic of the dynamic pattern. Results will be discussed as they relate to categorical perception and category learning. [Work supported by the NIH.]
Simulation of bone-conducted sound pathways to the inner ear.
Authors: O’Brien William
Published: October 2013

A project to determine bone-conducted sound pathways to the inner ear is sponsored by the Air Force in an effort to reduce hearing loss in personnel working in high-noise environments. The study includes a computer simulation, in three dimensional (3D), of an acoustic pulse wave propagating through and around a human skull. Numerical 3D simulations are benchmarked with known analytic results in order to verify accuracy. The pulse center frequency can be varied in order to identify how frequencies affect the vibrations of the skull. The program is used to validate an experimental mapping of the skull in which the response in the inner ear, with and without hearing protection, is measured as function of transducer input location at different external head locations and center frequency. An FETD algorithm written in MPI and executed on highly parallelized clusters is used to achieve these results efficiently. The mesh, on which the code operates, is a uniform grid of eight node brick elements. Thus the program can directly operate on any digitized image (in two dimensional) or a list of digitized images (in 3D) in which each image is a single slice of a 3D volume. [Work supported by AFOSR FA9550-06-0128.]
Numerical simulation of mechanisms of sound conduction through the human head with a fast elasto-acoustics integral equation solver.
Authors: Bleszynski Elizabeth , Bleszynski Marek , Jaroszewicz Thomas
Published: October 2013

The purpose of this paper is to describe our progress in development and applications of numerical simulation tools designed to (a) investigate mechanisms of energy transfer to cochlea through air- and bone-conduction pathways and to (b) assess effectiveness of suitable noise protection devices. Our numerical simulations employ a recently implemented acoustoelastic integral equation solver, capable (through the use of nonlossy fast Fourier transform based matrix compression algorithm and parallelization on distributed-memory systems) of accurate large-scale numerical simulations with anatomically realistic models of the human head, discretized with several millions of tetrahedral elements. Recently added new solver features (including treatment of shear waves, described in terms of node-based linear elements) enable us to analyze detailed aspects of acoustic/elastic wave interaction with the human head with significant accuracy and efficiency. In particular, they facilitate examination of the relative amounts of energy transferred to the middle and inner ears directly through the outer ear and indirectly via excitation of elastic waves in the skull and soft tissues. [This work is supported by AFOSR.]
Acoustic correlates of speaker discrimination in English.
Authors: Narayan Chandan , Yuan Jiahong
Published: October 2013

This study investigated speaker discrimination in utterances varying in syllable length and speaker gender taken from the TIMIT corpus of American English. Twenty native English speakers presented one-, two-, and three-syllable utterances (within speaker gender) in a two-alternative forced-choice task. Perception results were analyzed in light of both source level (F0 and long-term average spectrum of LPC residuals) and formant level measurements (F1–F4). Results showed that male speakers were discriminated better than female speakers. Source features (F0 and LTAS of LPC residuals) significantly predicted listener response, while higher spectral information (F1–F4) had little effect. The varying importance of vocal source and vocal tract characteristics in speaker discrimination is discussed.
Channel and language effects on reaction time in a voice identification.
Authors: Fasnacht Kyna , Bahr Ruth Huntley
Published: October 2013

Previous research has indicated that listeners have difficulty with bilingual speaker identification when voice samples are compared across languages [Bahr and Frisch (2002)]. Communication channel can negatively impact voice identification, but its effect on bilingual speaker identification has not been well defined. Reaction time has also been found to increase for speech processing when speaker accent is strong [Schmid and Yeni-Komshian (1999)]. Therefore, it is the purpose of this investigation to assess the effect of channel differences and language to determine how these factors influence recognition accuracy and processing time. A paired comparison listening task was used to evaluate monolingual listeners' performance when channel (laboratory quality, landline phone, and cell phone transmissions) and language (English versus various dialects of Spanish) were varied. Reaction time was recorded to investigate changes in processing demands. Results indicated that listeners were less accurate when channel conditions varied. Difficulties with language/dialect were more noticeable in conversation. These findings were evident in both the accuracy and reaction time data. The role of dialectal variation in the forensic speaker identification process will be described and related to findings from the stereotype literature, which describes “an other race effect,” i.e., all dialects of Spanish sound the same.
Examining the relationship between lexical access and the perceived strength of foreign-accents.
Authors: Shah Amee P. , McLennan Conor T.
Published: October 2013

Foreign-accented speech is one source of variability that listeners may face during the perception of spoken language. Although a number of previous studies have examined the role that foreign-accented speech plays in listeners’ ability to process spoken language, we are interested in examining the converse of this relationship. That is, previous work has demonstrated that accent manipulations affect listeners’ ability to process spoken language. For example, the speed and accuracy with which listeners access spoken words produced with a foreign-accent is compromised (at least initially) relative to the same words produced with a native-accent. However, the present study, which builds on our previous work [Shah and McLennan (2007)], examines whether manipulations known to affect listeners’ ability to access spoken words will affect listeners’ subjective judgment of foreign-accented speech. More specifically, because spoken words are typically easier to process when they have been heard recently (repetition priming), we investigated whether listeners would respond more quickly in an accent-rating task to primed words relative to unprimed words and/or whether primed words would be perceived as having been produced with a weaker foreign-accent. Results provide new information regarding the relationship between lexical access and the perception of foreign-accented speech.
Time course of talker-specific learning in spoken word recognition.
Authors: Nygaard Lynne C. , Sidaras Sabrina K. , Alexander Jessica E. D.
Published: October 2013

The current study examined the effects of talker-specific perceptual learning on the time course of spoken word processing to assess the point at which effects of talker familiarity emerge during spoken word recognition. Listeners learned to identify six talkers’ voices (three males, three females) over three days of training. At test, listeners either completed an immediate or a delayed word-shadowing task. Items at test were novel words produced by the six familiar talkers heard during training and by a set of six unfamiliar talkers. A separate group of controls completed the test phase only. The results indicated that effects of talker familiarity were found in both the immediate and delayed shadowing tasks. Listeners were faster to shadow words produced by familiar than unfamiliar talkers both when responding immediately to the word and when responding after a cued delay. When tested with unfamiliar talkers, the trained listeners did not differ from untrained controls. These findings suggest that effects of talker familiarity emerge relatively early in spoken word processing and persist as word recognition unfolds. Perceptual learning of talker-specific characteristics appears to influence the time course of lexical processing by facilitating the rapid recovery of the linguistic structure of spoken words.
Representation of multiple variant forms in spoken word recognition: Friends, not enemies.
Authors: Ranbom Larissa , Pinnow Eleni , Connine Cynthia
Published: October 2013

Prior research [Ranbom and Connine (2007)] showed that alternative variant forms of a word are represented in the lexicon as a function of variant frequency. Two experiments investigated whether these multiple representations conspire or compete during spoken word recognition of nasal flap variants. In experiment 1, nasal flap productions of high (i.e., “counter”) and low (i.e., “enter”) variant frequency words, as well as a set of nonword controls (i.e., “penter”), were presented in a phoneme monitoring task (detection of a /t/ sound). The results showed “higher-t” detection rates for words than for nonwords, and higher-t detection for high than for low-variant frequency words. Experiment 2 used truncated versions of the stimuli from experiment 1 and showed comparable t-detection rates across all conditions. The results suggest that coactivated multiple representations of phonological variants conspire during spoken word recognition.
Aircraft noise prediction.
Authors: Posey Joe
Published: October 2013

Noise has been an issue for airport communities and passengers since the advent of commercial air transport almost a century ago. Impressive gains have been made in aircraft noise control, but expectations are rising and air traffic will at least double in the next 20 years. Also, lighter composite structures pose a challenge for interior noise control. Furthermore, societal expectations for mobility, new technology, demands for carbon footprint minimization, and other environmental imperatives will lead to revolutionary aircraft designs in the future. This tutorial lecture will consider noise from present and future subsonic jet aircraft, rotorcraft, propeller aircraft, and supersonic transports. Noise prediction capabilities will be identified, along with an overview of noise control technology. Acousticians are preparing to predict and control community and interior noise for arbitrary configurations using models based more on first principles, whereas the state-of-the-art is largely semiempirical. It is imperative that acousticians be included in the early stages of the design process and for all design team members to have some exposure to noise control principles to avoid wasting resources on designs that should be nonstarters from the noise perspective.
An architect’s perspective on acoustics.
Authors: Siebein Gary , Bettcher Adam , Fisher Joshua , Robinson Threcia , Skelton Reece
Published: October 2013

The basis for conceptual thinking in architecture is simultaneously aesthetic, humanistic, and scientific. An architectural theory was developed that includes philosophical, aesthetic, and technical thinking about acoustics as generative ideas for form. This theory has its roots in defining an acoustic landscape or soundscape: both interior and exterior, where the soundscape is formed by the architectural ideas and the soundscape reciprocally defines the architecture. The ensuing dialogical exploration of form, space, material, occupation, and phenomenological qualities provides a basis for the mutual expression or poesis of architectural and acoustic designers. The theory was used as the basis for graduate studio design classes at the University of Florida and is presented through the work of several students.
Bypassing metrics and designing holistically use of site-specific auralizations.
Authors: Cushner Joshua
Published: October 2013

Acoustics as a discipline has developed many objective metrics to define subjective acceptance criteria. The most common metrics used by acousticians tend to be generalized in order to communicate effectively with clients and architects at the expense of accuracy. These generic criteria can be given undue importance on a particular project when a more site-specific investigation may indicate the criteria to be inappropriate. Simply stated, standard acoustic criteria can serve to create an artificial barrier to otherwise effective solutions and strain the consultant-architect and consultant-client relationship. However, resistance from deviating from standard criteria is understandable when few nonacousticians (and even some acousticians) can appreciate the qualitative aspects of a given criteria. Providing site-specific auralizations can serve to bridge the communication gap with architects and clients by moving from a criteria-based design to a performance based design. Through the process of site evaluation and design auralization, analyses can be provided which place the client or architect directly in the subject environment, where they are able to make value-based judgments, irrespective of generic criteria. Results from recent project studies show this approach to be useful to enhance communication with the architect and provide the acoustician with another useful analysis tool.
Methods for reducing flanking airborne noise transmission through mullions of curtain wall systems.
Authors: LoVerde John , Dong Wayland
Published: October 2013

Over the course of design of high-rise structures incorporating curtain wall design, there is a common limitation of the sound isolation that can be obtained at the intersection of demising partitions at the curtain wall. Approximately 45 years ago, Veneklasen Associates (VA) developed details to control the isolation. Through field testing and observations, this detailing was optimized. Approximately 15 years ago, VA constructed the intersection details in a laboratory to confirm the results from our experience. In the past 15 years, these details have further been advanced to create sound isolation in line with the desire of the user, including multifamily residential dwellings. VA shall present the historical detailing and modifications to the detailing and correlate this information with subjective and objective assessments of these constructions.
Why honor Dr. Sam H. Ridgway.
Authors: Evans William
Published: October 2013

Based on my 45 year association with Ridgway, I have summarized the accomplishment of this outstanding scholar and scientist. I discuss the transition from a clinical veterinarian to an accomplished researcher and innovator. Our understanding of animal bioacoustics, especially marine mammals, has been greatly influenced by his research. This is not only true in the U.S. but also in the international community. This includes the development and use of specialized techniques in advancing our understanding of the dolphin bioacoustics. His development and use of innovative methods in understanding the dolphin sound production and the impact of high level noise on dolphin hearing are significant contributions.
Anatomical, electrophysiological, and histological studies of dolphin auditory system: Establishment of a theory of hearing for dolphins.
Authors: McCormick James
Published: October 2013

Wever and I at Princeton University wanted to study hearing in dolphins utilizing Wever’s cochlear-potential recording method, which directly reflects the performance of the ear’s mechanical system. A method of humane anesthesia for dolphins for electrophysiological studies did not exist. Preliminary studies by Ridgway with halothane anesthesia published in 1965 seemed promising and motivated me and Wever to collaborate with Ridgway. Subsequently, Ridgway and I tested and perfected the use of halothane anesthesia for dolphins. This led to a coast to coast collaboration on dolphin hearing between Ridgway at Naval Missile Center Point Mugu and me and Wever at Princeton. Ridgway shared his expertise in Marine Mammal Medicine not only with us, but with the world, and in the process he became an expert marine mammal neuroscientist. Our three way collaboration demonstrated that the dolphin hears by bone conduction, with the middle ear ossicles acting as an inertial mass relative to the sound received in the lower jaw of the dolphin—the external auditory meatus and ear drum being vestigial.
Dolphin detection of targets as a function of angular presentation and target strength.
Authors: Moore Patrick , Dankiewicz Lois , Kastak David , Houser Dorian
Published: October 2013

As part of an ongoing study, bottlenose dolphin (Tursiops truncatus) echolocation beam steering was assessed as a dolphin performed a target detection task (4- and 7.62-cm spheres) while echolocating with its head held in a fixed orientation and monitored via underwater camera. Targets were placed approximately 4.0 m in front of the dolphin [zero degree position (P0)] and at 34 deg to the left and right of P0 (PL and PR). Echolocation clicks and echoes were digitized using a high-speed 32 channel analog-to-digital card, sampling 29 calibrated hydrophones with analog filter-amplifiers arranged in a diamond-shaped array supported in a hemispherical web in front of the animal. Using a yes-no response and a modified method of constants procedure with 0.50 target presence/absence probability, detection ability (d) and response bias (B) of the dolphin were computed for both targets at all positions. Detection thresholds (d) for the 4- and 7.62-cm spheres at P0, PL, and PR were 4.65, 2.08, and 2.62, and 4.08, 2.81, and 3.2, respectively. Beam characteristics were computed and beam steering was verified for this dolphin. These results also show angular detection at displacements about 8 deg farther from P0 than previous reports for spheres half as large.
An acoustic finite-element model to study sonar interactions with marine mammals.
Authors: Feijoo Gonzalo , Foote Kenneth
Published: October 2013

A computer model based on the finite-element method (FEM) is being developed to study the interaction of sonar signals with marine mammals. This model solves the Helmholtz equation in a computational box that includes the animal and the surrounding medium, water. The FEM code has been validated with analytical solutions for the scattering of a plane wave by a fluid sphere over a range of parameters and frequencies of interest. Then it has been applied to a specimen, a 142-cm-long common dolphin (Delphinus delphis), and internal pressure and displacement fields were computed. The animal is represented in the computer model by a set of tissue groups whose acoustic properties, density, and sound speed are taken from the literature. The geometry of each tissue group was constructed from segmented computerized tomography images. Results are presented for harmonic signals in the 1–10 kHz frequency range. [Work supported by NOPP through ONR award No. N000140710992.]
Beaked whale detection utilizing characteristics of foraging echolocation clicks.
Authors: Martin Stephen
Published: October 2013

A technique is presented for the automatic acoustic detection of beaked whale (family Ziphidae) foraging echolocation clicks. The technique currently employs a three-stage process. The first stage is an acoustic detection screener that uses a submillisecond detection window. The second stage analyzes for click frequency modulation characteristic of two species of beaked whale (Mesoplodon densirostris and Ziphius cavirostris). The third stage performs temporal filtering to reduce false positives using information such as individual beaked whale interclick interval characteristics. Results from nine test files (90 min of data from US Navy instrumented test ranges AUTEC and SCORE) show good performance on eight of the nine test files. The ninth test file (short finned pilot whale) exhibited 930 (assumed) incorrect calls out of 9893 screener detections (9.4%). Over 70 000 min of data from the US Navy Pacific Missile Range Facility were also processed with third stage detections ranging from 3423 to 84 240 beaked whale click detections (depending on temporal processing utilized) from over 13×106 screener detections.
Ship strike acoustics: A paradox with a parametric solution.
Authors: Gerstein Edmund , Blue Joseph , Forsythe Steven
Published: October 2013

Marine mammals are vulnerable to ship collisions when they are near the surface. Here acoustical laws of reflection and propagation can limit their ability to hear and locate the noise from approaching vessels. Defining the physics of near surface acoustical propagation as it relates to ship noise and hearing is central to understanding and mitigating ship strikes. Field data from controlled ship passages through vertical hydrophone arrays demonstrate a confluence of acoustical factors that poses detection challenges including (i) downward refraction, (ii) spreading loss, (iii) Lloyd’s mirror effect, (iv) acoustical shadowing, and (v) masking of approaching ship noise by ambient noise and distant ships. A highly directional, dual-frequency parametric sonar has been developed to mitigate these challenges and to alert marine mammals of approaching vessels. The system projector is a planar array, comprised of 45 elements, band centered to transmit a high carrier frequency along with a lower side band signal. The nonlinearity of water is used to demodulate the mixed high-frequency carrier into a lower-frequency waveform audible to both manatees and whales. The bow mounted arrays project a narrow beam directly ahead of vessels and “fill in” acoustical shadows in an effort to alert marine mammals of the approaching danger. [Work funded by the DOD Legacy Resource Management Program (Navy).]
Laboratory measurements of sound speed and attenuation in water-saturated artificial sediments as a function of porosity.
Authors: Argo Theodore F. , Guild Matthew D. , Wilson Preston S. , Radin Charles , Schröter Matthias , Swinney Harry L.
Published: October 2013

Several models have been proposed to describe the sound speed and attenuation of acoustic waves in water-saturated granular sediments. The difference between the predictions of competing models can be only a few percent, and it is difficult to obtain both sufficient knowledge of the sediment physical parameters and sufficiently small measurement uncertainty to adequately verify competing models. Furthermore, the inhomogeneity of natural sediments causes additional measurement and interpretation uncertainty. Therefore, well-controlled laboratory measurements are useful for model validation and also facilitate exploration of the effects of sediment physical parameter variation. A method for controlling the porosity of an ensemble of water-saturated granular particles [Schröter et al., Phys. Rev. E 71, 030301(R) (2005)] was used to prepare columns of artificial sediments, composed of monodisperse 280-μm-diameter glass spheres and distilled water of varying porosity. Acoustic time-of-flight measurements were used to determine the phase speed and attenuation of the material for frequencies from 250 to 800 kHz and for porosities from 0.37 to 0.43. The sound speed and attenuation measurements will be presented and compared to existing model predictions. [Work supported by ONR and the Robert A. Welch Foundation.]
Measurements of sound speed and attenuation for six kinds of water saturated glass beads.
Authors: Lee K. , Seong W.
Published: October 2013

Acoustic measurements of sound speed and attenuation were made in a laboratory water tank containing water saturated granular medium consisting of six kinds of glass beads each with mean grain sizes of 0.090, 0.150, 0.354, 0.507, 0.625, and 0.875 mm for several frequencies extending from 40 kHz to 1 MHz. Cross-correlation technique and time-of-flight technique are used to calculate the sound speed and attenuation of samples. In the presentation, the uncertainties of sediment preparation such as air-removal, grain packing, and depth-varying of sediment will be mainly discussed. Also, the observed patterns of the sound speed and attenuation will be presented for the mean grain size, grain size distribution, and frequency.
Time-frequency transformation by arrays of neural oscillators: Implications for musical structure.
Authors: Velasco Marc , Large Edward
Published: October 2013

A growing body of evidence is consistent with the possibility of nonlinear oscillation in both the peripheral and central auditory nervous systems. This talk will introduce a model of nonlinear time-frequency transformation via an array of neural oscillators, each tuned to a distinct frequency, organized along a frequency gradient. Transformation of sound stimuli by neural oscillators is characterized. Predictions about general properties of nonlinear time-frequency transformation, such as frequency detuning and higher-order resonance, are derived. The model is consistent with nonlinear resonance approaches to pitch perception. The perception of tonality is predicted as a global pattern of resonance regions at small integer ratio frequency relationships. Neural oscillation provides a substantive potentially universal principle underlying the basic materials of music, namely, pitch and tonality. [Work supported by AFOSR FA9550-07-C0095.]
Dynamics of tonality.
Authors: Janata Petr
Published: October 2013

As listeners of western tonal music, we establish mental representations of tonal space: the distance relationships between major and minor keys (tonal centers). Evidence for the distance relationships underlying tonal space derives from music theory, cognitive psychology, and statistical learning approaches. Tonal space is represented parsimoniously on the surface of a torus. Although the torus itself is a static structure, the movements of music about its surface are shaped by the nuances of melodies and harmonic progressions that mold the sense of the tonal center through time. Central to an understanding how our brains interact with music's dynamic movements in tonal space, and the main aspect of this presentation, is a consideration of the timescale(s) over which the movements are modeled. At long timescales, movements on the toroidal surface are slow and perhaps tend to reflect symbolic music-theoretic descriptions in which a series of stable tonal centers is established. When biased toward shorter timescales the toroidal dynamics reveal much livelier movement that depends on the tonal content of individual chords. Intermediate timescales reveal tonal dynamics between these two extremes, both stability and rapid transitions, and perhaps reflect the scale that most closely match our sense of tonal movement.
Operator algebra and coherent states for equally tempered scales.
Authors: Sevgen Alpar
Published: October 2013

The algebra that the equally tempered scales obey is [Sz,S±] = ±c1S± and [S±,S−] = 0, where all are modulo N relations, and c1 is the generator of the scale labels. The coherent states |λ,n〉 are eigenvectors of S− with eigenvalues λ and where λN = 1. Similarities and differences between these equations and the quantum mechanical angular momentum algebra are discussed. The mean square variation δSz2 in a coherent state depends on M, the number of notes in the scale. δSz2 is minimum for M = 8, and the next higher δSz2 value belongs to the customary M = 7. The same conclusions hold true also for the complementary scales with M′ = N − M notes. Thus, one may speculate about the possibility of using M = 8 and M = 4 tones in the N = 12 semitone equally tempered scales in musical compositions.
Revisiting “Acoustic information for objects, places, and events”.
Authors: Shafiro Valeriy
Published: October 2013

Over two decades ago, Jenkins proposed a broad taxonomy of acoustic information which addresses the perception of objects, places, and events in the world around the listener [J.J. Jenkins “Acoustic information for objects, places, and events,” Persistence and Change: Proceedings of the First International Conference on Event Perception, edited by W. H. Warren and R. E. Shaw, Erlbaum, (2006)]. Although lesser known than some of his other publications, this chapter has anticipated several future directions in auditory research by asking what is being perceived by the listener and why. Inspired by this taxonomy, our research on environmental sound perception by normal-hearing and cochlear implant listeners has investigated how objects and events are perceived when sensory input is degraded. Experiments with vocoded environmental sounds of varying spectral resolution indicate large differences among individual sounds in the amount of spectral resolution required for identification. Temporally patterned sounds generally need a lower spectral resolution than harmonically rich sounds. However, with training, perception of environmental sounds can substantially improve and generalize to novel sounds, potentially including speech. Findings in cochlear implant listeners further indicate strong correlations between speech and environmental sound perception abilities, suggesting a considerable overlap in the perception of these two ecologically significant sound classes.
Time-reversed maximal-length sequences for outdoor, underwater sound propagation, and room-acoustic artificial reverberation simulations.
Authors: Xiang Ning , Chu Dezhang
Published: October 2013

Pseudorandom properties of maximal-length sequences (M-sequences) have long been exploited for acoustic measurements. Time-reversed M-sequence pairs also possess unique correlation properties, including a two-valued autocorrelation function and a low-valued cross-correlation function, which make them excellent candidates for acoustic measurements using simultaneous dual-sources [N. Xiang and M. R. Schroeder, J. Acoust. Soc. Am. 113, 2754–2761 (2003)]. The application of time-reversed M-sequences was originally inspired by the outdoor acoustic tomography. This paper reports on a recent underwater experiment using the time-revered M-sequence pairs in a quasibistatic sonar system. Different from the baseband simultaneous acoustic excitations in outdoor sound propagation, the underwater application in the bistatic sonar requires ultrasonic amplitude modulation technique in order to exploit the desired correlation properties. Their excellent pseudorandom and correlation properties have also been exploited in room-acoustic applications. In addition to simultaneous dual-source room impulse response measurements, this paper also reports on creating artificial enveloping reverberations using time-reversed M-sequences.
Improved interference rejection in code-division multiaccess underwater acoustic communications: The near-far problem.
Authors: Yang T. C. , Yang Wen-Bin
Published: October 2013

Underwater acoustic communication is known for the signal latency due to the slow sound speed in water. This creates a severe scheduling problem for signal transmission in an underwater acoustic network involving mobile platforms or sensors, particularly when the ranges between the individual nodes are varying with time. Multiple-access communication methods such as code-division multiple-access (CDMA) that are widely used in radio frequency communications (mobile cellular network) have been considered. The problem is that the code orthogonality between the different users is destroyed by the presence of multipath arrivals in an underwater acoustic channel and severe Doppler shift in the signal. As a result, the ability to reject interference that is well known for CDMA signal is severely degraded resulting in a poor bit error rate. One approach is to recover the signal orthogonality by equalizing the multipath arrivals. However, performance of the equalization algorithm is itself degraded in the presence of interference. A different approach using the hyperspace cancellation by coordinate zeroing method is adapted in this paper for interference rejection without requiring channel equalization. Good performance is obtained using at-sea data. [This work is supported by the US Office of Naval Research.)
Barons, barns, bombs: Innovative unlikely homes for the arts.
Authors: Pfeiffer Scott
Published: October 2013

The School of the Art Institute, The Weston Playhouse, and The Peck School of the Arts all have made use of existing structures as augmentations of their facilities. Sustainability is served in these projects regardless of their pursuit of the U.S. Green Building Council Leadership in Energy and Environmental Design Certification. Adaptive reuse preserves the energy spent in the creation of the materials and the construction of the original building, as long as modern systems are introduced that allow the buildings to function efficiently. In each case, the unique qualities that made the buildings successful in their original use were exploited in their redevelopment. Issues of adapting structure, mechanical systems, and adapting to the local environment all guide the setting of priorities in the acoustic design. Special attention is paid to developing flexible infrastructure since clearly the second (or sometimes the third) use of the building will not be its last. The special problems overcome in retrofitting the existing space for the performing arts are discussed.
A new performance space for Temple University in the oldest building on campus.
Authors: Greenberg David , Doggett Felicia
Published: October 2013

Construction of the Baptist Temple on North Broad Street in Philadelphia was begun in 1899 and completed the following year. Temple University was founded within its walls and consequently where it got its name. The University purchased the building in 1972 where it remained vacant for several decades. In 2007, Temple University announced plans to adapt the structure as a multipurpose venue for orchestra and choral performances, jazz ensembles, drama, lectures, and convocations. The building includes the main worship space located above the Chapel of the Four Chaplains in the basement, both of which will be renovated into performance spaces. How does one renovate a wood-framed, volume-limited, noisy street side building with deep wraparound balconies and less-than-ideal mechanical equipment locations into a performance venue for a high-quality music department on a limited budget with demanding users and an ultra-cost-conscious owner while maintaining the historic fabric of the building? This presentation explores not only the details of the renovations but also the complicated relationships between the owner, the user, the architect, the acoustical consultant, and the peer reviewer.
Definition of a cavitation index for real time monitoring during in vitro liposomal drug release.
Authors: Somaglino Lucie , Bouchoux Guillaume , Mestas Jean-Louis , Matias Adrien , Chapelon Jean-Yves , Lafon Cyril
Published: October 2013

Drug release from liposomes can be activated by ultrasound and inertial cavitation is assumed to be the main involved mechanism. Broadband noise is known as a good indicator for such cavitation. The feasibility of assessing the extent of drug release by acoustic noise measurements has been investigated. A 1.17-MHz focused transducer (50-mm diameter and 50-mm focal length) was excited with tone-bursts (duty cycle: 10%–100%, PRF: 100 Hz–10 kHz, and Ispta < 800 W/cm2). Emitted noise was registered with a broadband needle hydrophone and bandpass filtered between the fundamental and the first harmonic frequency for assessing the instantaneous inertial cavitation activity. A cavitation index (CI) was computed by integrating the filtered signal over time. This index was validated experimentally using terephthalate oxidized to fluorescent hydroxyterephthalate under the action of free hydroxyl radicals generated by inertial cavitation. The hydroxyterephthalate fluorescence and the CI were well correlated (R2≃0.92). Experiments with liposomes were performed showing very good correlation between CI and drug release extent from liposomes. The definition of this CI allowed applying consistent doses of cavitation and performing comparative tests between different liposome formulations. [This work was funded by a grant from the Norwegian Research Council (NANOMAT programme). Epitarget AS, Norway is acknowledged for the supply of liposome samples.]
Coupling coefficient of segmented stack piezoelectric transducers using high-coupling materials.
Authors: Thompson Stephen C. , Meyer Richard J. , Markley Douglas C.
Published: October 2013

High-power piezoelectric transducers normally use a segmented stack of piezoelectric pieces. The pieces are arranged with alternating polarization and are driven by electrodes of alternating voltage polarity. This allows long stacks to be built from easily manufactured pieces and reduces the voltage required for full power operation. The common understanding among transducer designers is that the mechanical properties of the stack of n pieces are equivalent to those of a single piezoelectric piece of equal total length, while the electrical impedance is reduced by the factor n2. For conventional designs with operating bandwidth less than a half octave, this is quite accurate. However, as new materials with high-electromechanical coupling make it possible to design high-power transducers with bandwidths greater than an octave, the use of segmented stacks must be reexamined. With high coupling materials, there is a significant reduction in effective coupling coefficient caused by stack segmentation. The effect is small for materials such as hard PZT, but is larger in at least some transducers built from materials with coupling coefficient above 80%. This paper will address the effects of stack design based on modeled and measured results. [Work supported by the Office of Naval Research.]
Verification of a method for measuring magnetostrictive parameters for use in transducer design modeling.
Authors: Porter Scott , Scott Ryan , Meyer Richard , Thompson Stephen
Published: October 2013

Previous studies have initiated an investigation into a new method of measuring the d33, μ33T, and s33H magnetostrictive constants of a given sample using a pair of Helmholtz coils, a laser vibrometer, and a sense coil. These parameters are calculated from measurements made as a function of dc magnetic bias and ac drive amplitude. This method contrasts with the traditional measurement technique which involves building the sample into a transducerlike device. The new method was demonstrated for laminated stress-annealed Galfenol rods of high aspect ratio. Measurements obtained by this method appear credible and demonstrate good repeatability. For verification, the authors have returned to the established approach and designed a simple transducer using one of the measured Galfenol rods. The transducer was driven in air as a function of dc magnetic bias and ac drive amplitude. Data obtained from this transducer are compared to an analytical model that uses the material properties obtained experimentally with the new method. [This work was sponsored by the Office of Naval Research (Contract N00014-06-1-0530) and by Etrema Products, Inc.]