bluuebunny/crossref_metadata_2025 huggingface dataset:
Broadband temporal and spectral structure of acoustic backscatter from Hawaiian Lutjanid snappers
Authors: Au Whitlow W. L. , Benoit-Bird Kelly J.
Published: October 2013

The characteristics of acoustic echoes from six species of deep dwelling (up to 350 m) Hawaiian Lutjanid snappers were determined by backscatter measurements at the surface. A broadband linear frequency modulated signal and a short dolphin-like sonar signal were used as the incident signal. The fishes were anesthetized and attached to a monofilament net which was in turn attached to a rotor so echoes could be collected along the roll, tilt, and lateral axes. The echo waveforms were complex with many highlights and varied with the orientation of the fish. The highlight structure was determined by calculating the envelope of the cross-correlation function between the incident signal and the echoes. In the tilt plane, the strongest echo occurred when the incident angle was perpendicular to the long axis of the swim bladder. The number of highlights was the fewest at this perpendicular orientation and increased as the fish is tilted from this orientation. The echo structures were easily distinguishable between species and were generally consistent within species. The highlight structure of the echoes resulted in the transfer function being rippled, with local maxima and minima at different frequencies.
The influence of reed curvature on the tone quality of lingual organ pipes
Authors: Plitnik G. R. , Angster J.
Published: October 2013

Given certain design constraints, such as the type of stop being voiced and the desired tone quality, reed voicers must use consummate skill to curve each tongue so as to produce the best and most stable tone, as well as maintaining a consistent tone quality across an entire rank of pipes. The curvature given to a reed tongue influences not only the harmonic structure of the steady-state sound, but also the attack. Two fundamentally different types of curvature are typically employed, the chorus reed (trompette) curve (which yields a bright sound) and the smooth-toned curve employed for solo reeds such as the clarinet. This study investigated the effect of reed curvature on the vibration and tone of reed tongues of both types. Two F2 pipes (a trompette and a clarinet) were constructed and voiced with 6 different tongues each to produce a variety of tones. The reed’s vibration was measured under typical conditions by laser vibrometer; the pressure waves in the boot and in the shallot were measured by means of one-eighth inch microphones and the emitted sound was recorded at the egress. By performing various measurements simultaneously, phase differences were also determined.
Conflicting noise ordinances in a metropolitan city
Authors: Kennedy Allan K.
Published: October 2013

Controlling community noise has become an important aspect in most communities. The desire to provide an environment that is acceptable and peaceful to residents and conducive to businesses sometimes creates conflicts in the regulatory requirements. This conflict is compounded in metropolitan cities where many communities are adjacent. Each community has a set of priorities for its citizens directing how ordinances are written and what sound limits are permitted on certain land uses. Noise ordinances in a United States metropolitan area with a population of 1.5 million were reviewed for their similarity and dissimilarity with respect to zoning. It was discovered that even though the communities share the same borders, they have vastly different noise limits in terms of amplitude, time of day, required parameter (Leq, Ldn, etc.), and land use. The conflicts arise for noise sources that are located at the borders of these cities.
Comparison between procedures of previsions in sound propagation in a quarry
Authors: Sarri Emanuele , Alfaro Degan Guido
Published: October 2013

The aim of this work is to compare the accuracy of numerical previsions of sound propagation in a quarry obtained with different algorithms. A comparison is made between the ISO 9613-1/2:1993 (E) standard for outdoor sound propagation, a new simplified algorithm based on the ISO code, a pyramid beam tracing method, and experimental measurements. The ISO 9613 standard proposes a detailed and complex method taking into account air absorption. It also takes into account the effects caused by the propagation over soil with varying properties, shielding both from thin and thick obstacles as well as the effects of vegetation layers and excess attenuation. The new algorithm simplifies ISO codes proposing an easy method, specific for a quarry. Pyramid beam tracing, implemented in Ramsete sound propagation software, is typically used to simulate sound fields in large rooms and also outdoors. Experimental and simulated data were used to built graphic plots, enabling a direct comparison of the results.
Study of noise external to public hospitals in the metropolitan area of Guadalajara
Authors: Orozco Martha , Garcia Javier , Hernandez Gabriela , Figueroa Arturo , Macias Jorge , Delgadillo Alan , Vazquez Esmeralda , Rivera Maria del Carmen
Published: October 2013

Environmental noise is at the present time a cause of concern, for the serious nuisance that it causes, and also the effects on health and behavior of individuals, on human activities, as well as for the psychological and social consequences. Hospital centers are places where numerous factors of quality and degradation can affect the recovery of patients. Knowing the acoustical conditions in some of the main hospitals of the city will make it possible to suggest measures to assist the present problem. We sampled 7 hospitals. The measurement points were selected at corners and at representative points or areas of pedestrian and vehicular entrance, a minimum of 4 points per block. We detected critical points of environmental noise in the vicinity of the hospitals, that require urgent attention. Some of the critical levels of noise were for LEQ, 93.4 and averages of this around 84.63 and maximum levels of 114.2, caused by an ambulance siren.
Effect of turbulence on the risetime of sonic booms and spark generated N waves
Authors: Lipkens Bart , Blanc-Benon Philippe
Published: October 2013

The risetime of acoustic pulses, such as sonic booms and electric spark generated N waves, is affected by propagation through turbulence. Risetime increases with increasing propagation distance and turbulence intensity. Data from electric spark propagation through turbulence show that Pierce’s wave front folding theory (1971) correctly describes the dependence of risetime τ on propagation distance x, i.e., τ∝x11/7, and turbulence kinetic energy dissipation rate ε, i.e., τ∝ε4/7. More recently, Pierce (AIAA-95-105) also derived a dispersion relation for acoustic pulse propagation through turbulence. The dispersion relation leads to an extra term in the propagation equation and takes into account the averaged contribution of all or part of the turbulence spectrum. A review of the dispersion theory is presented. Then a Van Kármán turbulent kinetic energy spectrum is used to obtain an accurate representation of both very large and very small turbulence structures. New results are compared with previous results obtained with a Kolmogorov spectrum.
Scattering of sound by a penetrable sphere above a plane boundary
Authors: Lui Wai Keung , Li Kai Ming
Published: October 2013

The problem of acoustic scattering by a penetrable sphere irradiated by a point source is investigated. A theoretical model is developed for the case of scattering by a sphere placed above an acoustically hard and an impedance boundary. The sphere is made of an extended reaction material that is assumed to be acoustically penetrable. The problems are tackled by using the technique of variables separation and appropriate wave field expansions. By adopting an image source method, the solutions can be formulated in form of multiscattering interaction between the sphere and the image sphere near a hard and an impedance boundary. The effect of boundary impedance on the reflected sound fields is incorporated in the numerical model by using the well-known Wely–van der Pol formula. Preliminary indoor measurements are conducted in an anechoic chamber for the characterization of the acoustical properties of the penetrable sphere as well as the impedance boundary. A further set of experimental measurements is carried out to demonstrate the validity of the proposed theoretical models for various receiver locations around the sphere above the impedance boundary. [Work sponsored by the Innovation & Technology Commission, MTR Corp. Ltd., and The Hong Kong Polytechnic University under Project No. ZM07.]
Nonlinear acoustics—Coupling between hydrodynamic and acoustic pressure fields
Authors: Pazini Brandao Mauricio
Published: October 2013

Linear or Classical Acoustics considers that sound waves propagate essentially without any medium movement. However, in Aeroacoustics we deal with phenomena where there are the simultaneous generation and propagation of sound in a moving medium. Unless the flow velocity is very low, when in aerodynamics the fluid can be modeled as being incompressible, nonlinearities must be taken into account to better model the flow physics. In this paper, by considering the exact mass and momentum equations in the form of a generalized Ffowcs–Williams and Hawkings equation, the coupling between the hydrodynamic and acoustic pressure fields generated by the motion of a solid body in still air is studied. The extent of the validity of linear hypotheses and decoupling between the two pressure fields is discussed. Strategies to consider the coupling for faster movements are indicated. This coupling appears in computations as stepwise linear iterations between the hydrodynamic and acoustic perturbation pressure fields. The goal of this research is to devise a mathematical and computational model where the formation of normal shock waves in transonic flows appears as a nonlinear interaction process between aerodynamics and aeroacoustics.
Transient modeling of Lamb waves emitted by integrated transducers using a hybrid finite element–normal mode expansion technique
Authors: Duquenne Laurent , Moulin Emmanuel , Assaad Jamal , Delebarre Christophe
Published: October 2013

For a few years, the concept of integrated health monitoring of aeronautic structures has become an important issue. A promising solution is the emission of ultrasonic Lamb waves using thin piezoelectric transducers integrated to the structure. Indeed Lamb waves are known to be able to propagate over long distance and to interact with inner structural defects. One important aspect when applying Lamb waves to health monitoring is the control and optimization of their generation. Therefore, a hybrid finite element–normal mode expansion modeling technique adapted to piezoelectric transducers has been recently developed. This technique allows the determination of the amplitude of each Lamb mode as a function of the transducer parameters. So far, it had been successfully applied to the case of harmonic excitation only. In this paper, adaptation of this hybrid technique to transient excitation is presented, which enables to simulate actual experimental conditions. Contrary to other techniques presented in the literature, the present technique allows to take into account the actual electromechanical behavior of the integrated transducer. Predicted results have been successfully compared to experimental measurements performed on different types of materials.
Sound radiation of a discontinuous structure calculated with various semianalytical and numerical methods
Authors: Zeitler Berndt , Möser Michael
Published: October 2013

The subject of investigation is an infinitely long radiator with the cross section of a pie slice. The modal radiation efficiency and directivity pattern are calculated for given normal velocity on the surface; rigid legs are assumed. Three semianalytical methods and one numerical method are used. The Wave-Approach (WA) splits the field into two regions assuming different wave types in each. Their amplitudes are chosen to fulfill the surface boundary conditions and to ensure a smooth transition between the regions. The Multi-Point–Multipole-Approach (MPMA), as the name suggests, uses several multipoles scattered within the structure, whose amplitudes are chosen such that the reconstructed normal velocity on the surface ideally equals the original. In this study the order is limited; only one mono- and two perpendicular dipoles are used. No restriction of order is made in the Single-Point–Multipole-Approach (SPMA), but of course one of quantity. For the Finite-Element-Method (FEM) Sommerfeld’s radiation condition was chosen as the outer boundary condition. The results for different criteria and under certain circumstances are compared and discussed. The sound radiation is also visualized through animations displaying particle movement.
Development of an Argentine Spanish hearing impaired speakers database
Authors: Gurlekian Jorge A. , Sanchez Navarro Ana
Published: October 2013

Argentine Spanish hearing impaired speech has not been systematically registered or studied. A database with standardized methods for data collection and labeling is presented here. Speech of 600 speakers, adults, and children, with different types of hearing losses is recorded at 44100 Hz and 16 bits. The corpus consists of word lists, grouped by tonality and frequency of use, and five short sentences, containing all the phonemes and allophones. Semi-spontaneous speech, consisting of a description of two sets of simple pictures, is also recorded. Data are acoustically analyzed and labeled at the segmental—graphemic, phonetic and acoustic tiers—and suprasegmental levels, using a labeling method that incorporates psychoacoustic information into a combination of categorical and continuous descriptions of fundamental frequency. Syntactic labels are added to semi-spontaneous speech data. Labeled files are loaded into a relational SQL database to allow different types of queries. A complementary database provides information about personal and medical data, and results of hearing tests. These databases contribute to the description of acoustic-phonetic features of deaf speech, a comparison between speech perception and production, and new approaches for the adjustment of auditory prostheses. [Work supported by FONCYT, CONICET and Mutualidad Argentina de HipoacB̄4usicos.]
Beam-based matched field steering for large volumetric arrays
Authors: Cox Henry , Heaney Kevin D.
Published: October 2013

A new approach is introduced to significantly improve the efficiency of generation of matched field steering vectors for large volumetric arrays. For a volumetric array it is shown that there is a virtual Equivalent Vertical Line Array (EVLA) with many fewer elements that captures all of the information contained in the acoustic propagation from a far field source to the receiving array. A relationship between the size of the virtual EVLA and the geometry of the volumetric array is derived. Element-based matched field steering vectors for the virtual EVLA can be computed in the usual way and then used to generate beam-based matched field steering vectors for shaded plane wave beams. By matching the mainlobes of the shaded plane wave beams of the virtual EVLA with the vertical beam pattern of the beams of the volumetric array, the beam-based steering vectors for the large real volumetric array are obtained without needing to compute its element-based steering vectors. For large volumetric arrays the savings can exceed an order of magnitude.
Deriving the spatial distribution and properties of radiating acoustic sources in a ship from a measurement of its signature in shallow water
Authors: Hall Marshall V.
Published: October 2013

When a wideband point source passes a hydrophone in shallow water, the spectrogram of the signature shows a characteristic interference pattern. This pattern consists of a number of bands of strong signal, which decrease in frequency as the source approaches, and pass through minimum frequencies at the closest point of approach (CPA). If the environmental waveguide is range-independent the spectrogram is symmetric around the time of CPA. The geoacoustic model of the seabed is determined by using an optimization routine to match the computed with the measured spectrogram. For a hydrophone in the nearfield of a passing ship, the bands in the spectrogram are less clear, and are asymmetric even if the waveguide is range-independent. The objective is to represent a ship by a small number of point sources distributed in space, each of which has its own spectrum and effective directionality. The main source, the propeller, is directional in effect because the hull is an obstacle to transmission in the forward direction. For each source, the spectrum and directionality are expressed as functions of frequency and angle. The function coefficients are determined by using an optimization routine to match the computed with the measured signature.
Passive subtractive beamformer applied to line sound sources
Authors: Mizumachi Mitsunori , Nakamura Satoshi
Published: October 2013

Speech is an attractive interface for mobile equipment if it is clearly received. A microphone array aids in reducing noise and enhancing speech. A small-scale microphone array generally adopts the subtractive beamforming technique, which constructs sharp notches in a beampattern in either an active or a passive way, so that target sound sources are assumed as point sound sources. However, the shapes of actual sound sources are various and not always points. In particular, the mouth needs to be modeled as line sound source or plane sound source. Therefore, beamformers should target line sound sources. A passive subtractive beamformer is proposed to expand width of a sharp notch by combining several 2ch subtractive beamformers. In multiple sound source conditions, it is necessary to avoid the effect of spatial aliasing against nontarget sound sources. Then, a hybrid technique is applied to realize an optimal connection of the quadruple, double, and single subtractive beamformer for the low, middle, and high frequency region. The feasibility of the proposed subtractive beamformer is confirmed by performance evaluation in suppressing the signals from line sound sources. [Work supported by the Telecommunications Advancement Organization of Japan.]
Recent developments in automatic classification of musical instruments
Authors: Kostek Bozena
Published: October 2013

In this paper recent developments in automatic classification of musical instrument domain are presented. Issues related to automatic classification of music are data representation of musical instrument sounds, automatic musical sound recognition, musical duet separation, music recognition, etc. These problems belong to the so-called Musical Information Retrieval domain. The best developed is the automatic recognition of individual musical sounds. In rich literature on this subject many references can be found. Another issue deals with music information retrieval understood as searching for music-related features such as song titles, etc. A query-by-humming can be also cited as one of the MIR topics. The most difficult problem that deals with automatic recognition of multipitch excerpts still remains unsolved, however, recently some approaches to this issue can be found in the literature. Some of the mentioned problems were subjects of the research carried out at the Sound & Vision Department of the Gdansk University of Technology. The developed solutions in the domain of automatic classification of individual sounds, duet separation, and music recognition will be presented as examples of possible case-studies in the MIR domain. The proposed approach was evaluated on musical datebases created at the Department. [Work supported by KBN, Grant No. 4 T11D 014 22.]
Hypersignal analyses of orchestral instrument signals as correlated with perception of timbre
Authors: Kendall Roger A.
Published: October 2013

Experiments were conducted to assess the relationships among signal analyses and timbral perception across the playing range of bassoon, trombone, tenor saxophone, alto saxophone, soprano saxophone, French horn, violin, oboe, flute, clarinet, and trumpet. Spectral analyses employed Hypersignal using 9th order Zoom FFT on 22.05 samples/s signals. Spectral centroid and spectral flux measures were calculated. Perceptual experiments included similarity scaling and identification at various pitch chroma across the playing range of the instruments. In addition, a pilot experiment assessing the interaction of pitch chroma and timbre was conducted where timbral judgements were made across, rather than within, pitch chroma. Results suggest that instruments with relatively low tessitura produce higher centroid ranges since the larger air column yeilds a large number of vibrational modes. In contrast, higher tessitura instruments, using smaller air columns, produce fewer modes of vibration with increasing pitch chroma, to the point that the centroids coverge near Bb5. Perceptual data correspond to the spectral, resulting in less specificity among instruments at their higher tessituras. It is suggested that spectral centroid, which maps strongly near A4 in the majority of studies, must be viewed with caution as a predictor of timbre at tessitura extremes.
A confirmatory analysis of four acoustic correlates of timbre space
Authors: McAdams Stephen , Caclin Anne , Smith Bennett K.
Published: October 2013

Exploratory multidimensional scaling studies of musical instrument timbres generally yield two- to four-dimensional perceptual spaces. Acoustic parameters have been derived that correlate moderately to highly with the perceptual dimensions. In a confirmatory study, two three-dimensional sets of synthetic, harmonic sounds equalized for fundamental frequency, loudness, and perceived duration were designed. The first two dimensions corresponded to attack time and spectral centroid in both sound sets. The third dimension corresponded to spectral flux (variation of the spectral centroid over time) in the first set and to the energy ratio of odd to even harmonics in the second set. Group analyses of dissimilarity judgments for all pairs of sounds homogeneously distributed in each space revealed a two-dimensional solution for the first set and a three-dimensional solution for the second set. Log attack time and spectral centroid were confirmed as perceptual dimensions in both solutions. The even/odd energy ratio was confirmed as a third dimension in the second set. Spectral flux was not confirmed in the first set, suggesting that this parameter should be re-examined. Analyses of individual data sets tested for differences across listeners in the mapping of acoustic parameters to perceptual dimensions. [Work supported by the CTI program of the CNRS.]
The wave digital piano hammer
Authors: Bilbao Stefan D. , Smith Julius O. , Bensa Julien , Kronland-Martinet Richard
Published: October 2013

For sound synthesis purposes, the vibration of a piano string may be simply modeled using bidirectional delay lines or digital waveguides which transport traveling wavelike signals in both directions. Such a digital wave-type formulation, in addition to yielding a particularly computationally efficient simulation routine, also possesses other important advantages. In particular, it is possible to couple the delay lines to a nonlinear exciting mechanism (the hammer) without compromising stability; in fact, if the hammer and string are lossless, their digital counterparts will be exactly lossless as well. The key to this good property (which can be carried over to other nonlinear elements in musical systems) is that all operations are framed in terms of the passive scattering of discrete signals in the network, the sum of the squares of which serves as a discrete-time Lyapunov function for the system as a whole. Simulations are presented.
Airborne chemistry single cell level
Authors: Nilsson Staffan , Viberg Peter , Spegel Peter , Santesson Sabina , Cedergren Eila , Degerman Eva , Johansson Tomas , Nilsson Johan
Published: October 2013

A miniaturized analysis system for the studying of living cells and biochemical reactions in microdrops was developed. Cell studies were performed using single adipocytes in 250-nL drops. Continuous flow-through droplet dispensers, developed in-house, were used for additions to the levitated droplet. Addition of b-adrenergic agonists stimulates the lipolysis in the adipocytes, leading to free fatty acid release and a consequent pH decrease of the surrounding buffer, a change that can be easily followed using a pH-dependent fluorophore continuously monitored by fluorescence imaging detection. An analytical method using capillary electrophoresis and nanospray mass spectrometry for measurement of the cAMP level in activated single adipocytes are now being developed for future use in combination with the levitation technique. The levitation approach was also employed for the screening of nucleation conditions for macromolecules. Here, the acoustic levitator offers a simplified way to determine the main features of the phase diagram (i.e., precipitation diagram). Using the droplet dispensers, different types and amounts of precipitation agents are injected into the levitated drop, allowing a systematic search for nucleation conditions that is not possible using standard crystallization methods. Once the precipitation diagram has been obtained, optimization using standard methods is employed to grow the crystals.
Visual bias on sound location modulated by content based processes
Authors: Frissen Ilja , de Gelder Beatrice
Published: October 2013

Ventriloquism refers to a perceptual phenomenon in which the apparent location of a sound source is displaced in the direction of a synchronous but spatially disparate visual stimulus. It is generally accepted that spatial and temporal proximity are factors facilitating crossmodal integration. Here we investigate whether content based processes could also play a role. In order to control for strategic factors, a psychophysical staircase method (Bertelson and Aschersleben, 1998) was adopted. Auditory stimuli were digital recordings of vowels (/i/ and /o/). Visual stimuli were digital pictures of talking faces articulating the same vowels, and a scrambled face. We ran eight concurrent staircases. In half of these the auditory stimuli were paired with the corresponding face, and in the other half with the scrambled face. Half the staircases started from the extreme left and the other from the extreme right. Presentation of staircases was randomized. Participants were asked to judge whether the sound was coming from the left, or from the right, of the median plane. On the staircases with a face stimulus, reversals started to occur significantly earlier than with a nonface. Thus, a ‘‘realistic’’ stimulus pairing enhances crossmodal integration.
Visual speech recalibrates auditory speech identification
Authors: Bertelson Paul , Vroomen Jean , de Gelder Beatrice
Published: October 2013

Exposure to spatially incongruent auditory and visual inputs produces both immediate crossmodal biases and aftereffects. But for event identification, rather than localization, only biases have been demonstrated so far. Taking the case of incongruent audiovisual speech, which produces the well-known McGurk bias effect, we show that, contrary to earlier reports (e.g., Roberts and Summerfield, 1981), aftereffects can be obtained. Exposure to an ambivalent auditory token from an /aba–ada/ continuum combined with the visual presentation of a face articulating /aba/ (or /ada/) increased the tendency to interpret test auditory tokens as /aba/ (or /ada/). The earlier results that were taken as disproving the possibility of visual recalibration of auditory speech identification were obtained with exposure to nonambiguous auditory tokens that (as we confirm in another experiment) create an auditory contrast effect in a direction opposite that of recalibration, and presumably masked the effect of recalibration.
Factors affecting frequency discrimination by poor readers
Authors: Bailey Peter , Snowling Maggie , Griffiths Yvonne , Hill Nick
Published: October 2013

Some of the experiments on frequency discrimination by groups of poor readers have shown impairments relative to normal-reading control groups, while other experiments have shown no reliable group differences. It remains uncertain to what extent these differences in outcome are attributable to individual differences in the severity of a sensory processing deficit associated with dyslexia, or to use different psychophysical procedures that make different demands of higher-level cognitive processes (such as attention and memory) which may be compromised by dyslexia. To explore these issues, pure-tone frequency difference limens (DLFs) were measured for groups of dyslexic adults and normal-reading controls in conditions incorporating a range of procedural manipulations. Dyslexic and control participants’ DLFs did not differ reliably when the procedure involved four-interval trials, but dyslexics’ DLFs were larger than controls using two-interval trials. The relative difference between dyslexic and control participants’ DLFs found using two-interval trials did not differ systematically across conditions involving a fixed or roving standard frequency, long or short duration stimuli, long or short interstimulus intervals, or interstimulus intervals that were either silent or included interpolated tones. The results suggest no obvious link between elevated DLFs and impaired short-term pitch memory in these dyslexic participants.
A vibration technique for measuring railroad rail stress
Authors: Damljanovic Vesna , Weaver Richard L.
Published: October 2013

Longitudinal rail stress, related to constrained thermal contractions and expansions, leads to broken and buckled rails, and consequent service delays and derailments. There is a broad consensus on the need for cost-effective and reliable methods for the measurement of rail stress. Vibration techniques for assessing rail stress, based on the effect of longitudinal force on the free vibrations of beams, have long been proposed. It is well understood that compressive stresses decrease the flexural frequencies, while tensile stresses increase them. Past efforts attempting to use this for measurements of stress in railroad rails have failed due to an inability to control or adequately measure other parameters, most particularly the placement and stiffness of the supports. We are developing a new method in which the influence of support parameters should be minimal. Scanned laser vibrometry measurements of vibration fields, followed by a comparison with guided wave theory for the complex cross section of the rail, promises to allow the stress to be determined with the requisite precision. Here we report on the status of this work. [Work supported by Association of American Railroads and the Transportation Research Board.]
Context dependencies in vowel identification in ablated CVC syllables
Authors: Talley Jim
Published: October 2013

In previously reported work [Talley, J. Acoust. Soc. Am. 108, 2601 (2000)], novel results from a new perceptual study of human vowel identification under ablation conditions were discussed. That study, which used ten American English (AE) vowels in each of four simple CVC consonantal contexts, found highly significant effects of ablation condition and consonantal context on vowel identifiability. However, little insight was available at the time regarding the specifics of the vowel–context interactions. This paper extends that work providing detailed analysis of vowel identification sensitivity relative to consonantal context under differing ablation conditions.
The identification and discrimination of English vowels produced by native Mandarin speakers
Authors: Chen Yang , Robb Michael
Published: October 2013

Individuals who speak an Asian language as their first language (L1) are reported to show phonetic inaccuracies in their production of English spoken as a second language (L2) [Flege, 1989]. Phonetic inaccuracies are assumed to arise from the phonetic differences between the two languages, whereby L1 competes with L2 production [Flege et al., 1997]. A small database is currently available in regarding the influence of Mandarin on the production of American English vowels. The present investigation is to perform a detailed acoustic and perceptual evaluation of American English tense–lax vowel pairs produced by 40 native Mandarin speakers. The Mandarin language does not contain lax vowels, therefore, examining the production of American English tense–lax pairs will provide a critical assessment of a native Mandarin-speaking individual’s ability to differentially produce English vowels. The first hypothesis to be tested will be that Mandarin speakers will demonstrate indistinctive acoustic tense–lax vowel differentiation in their English productions. The second hypothesis to be tested will be that Mandarin speakers will be judged perceptually as less successful in differentially producing the adjacent tense–lax English vowel pairs as compared to the American speakers. The phonetic influences of L1 (Mandarin) on L2 (English) will be discussed.
Production and perception of vowels in Karitiana
Authors: Demolin Didier , Storto Luciana
Published: October 2013

The main acoustic features of vowels in Karitiana, a language of the Tupi stock spoken in Brazil are examined. This language has 5 vowel qualities [i,e,a,o,l/] which can be oral (short and long) and nasal (short and long). This vowel system has no high back vowel [u]. The main characteristics are that short oral vowels have a wider distribution than long oral vowels; nasal vowels are centralized when compared to oral vowels; length measurements show that central vowels are very short; whatever their quality short nasal vowels have similar length; the difference between short and long nasals is less than in the oral dimension. The dynamic characteristics of nasal vowels where there is a characteristic rising movement of F2 are also examined. Finally a perception test was carried out to understand how Karitiana vowels are perceived by native speakers. The test used a set of 58 synthetic stimuli which covers the vowel space. The main results show that speakers easily recognize peripheric vowels while central vowels are less salient. Karitiana speakers did not identify any stimuli in the area of the high back vowel.
Analysis of monostatic and bistatic reverberation measurements on the Scotian Shelf
Authors: Ellis Dale D. , Preston John R.
Published: October 2013

During the Boundary 2001 sea trial, a number of long-range reverberation measurements were made at a site on the Scotian Shelf between Halifax and Sable Island. The water depth was about 80 m over a sandy bottom. The sources were SUS charges dropped from either the NATO research vessel Alliance or the Canadian research vessel CFAV Quest. The receiver was the SACLANTCEN 254-m towed array aboard Alliance. The data were analyzed in two array apertures and frequencies from 80 Hz to 1400 Hz. Model-data comparisons were made using the Generic Sonar Model, with bottom parameters being extracted using both a manual procedure and an automated procedure. Direct measures of the scattering and bottom properties were made by other researchers, including Hines, Holland, and Osler. The bottom topography was fairly smooth near the site, but at long ranges there were numerous scattering features. The polar plots of the data, and model-data differences, are compared with the bathymetric features in the area. [Work supported in part by ONR Code 32, Grant No. N00014-97-1-1034.]
Auditory grouping in the túngara frog: The roles of complex call components in what and where decisions
Authors: Farris Hamilton , Rand A. Stanley , Ryan Michael J.
Published: October 2013

Like humans, numerous animals across disparate taxa must identify and locate complex acoustic signals imbedded in multiple overlapping signals and ambient noise. A requirement of this task is the ability to group sounds into auditory streams in which sounds are perceived as emanating from the same source. Although comparatively few assays have demonstrated aspects of auditory grouping in nonhuman animals, Capranica and colleagues have revealed several excellent examples through their work with anuran bioacoustics. In this study, we build on their work by presenting evidence for auditory grouping in túngara frogs (Physalaemus pustulosus). The complex calls of P. pustulosus consist of two discrete components, which are commonly produced in multi-male choruses. By measuring the phonotactic responses of females to spatially segregated components, we show that, in contrast to humans, spatial cues play a limited role in grouping, as grouping occurs over wide angular separations. In addition, the presentation of spatially segregated call components allowed us to measure the behavioral significance of each component in the complex. We show that once grouped the separate call components are weighted differently in recognizing and locating the call, so-called ‘‘what’’ and ‘‘where’’ decisions, respectively.
How long do females listen? Assessment time for female choice in the gray treefrog, Hyla versicolor
Authors: Schwartz Joshua J.
Published: October 2013

A satisfactory understanding of the process of mate choice by female frogs requires that we know how sensitive females are to the variation in males’ calls under natural conditions and what is the time scale or ‘‘window’’ over which females compare males. In natural choruses, gray treefrog females may sit near calling males for many minutes before approaching a particular individual to mate, while in laboratory-based tests they may approach a speaker following less than 30 s of exposure to broadcast calls. Females prefer long to short calls. In order to estimate ‘‘assessment time’’ of females in nature, calls were broadcast from four pairs of 360-deg speakers surrounded by screen cages at a pond in Missouri. One speaker per pair presented calls of constant duration, while the other speaker shifted between calls longer or shorter than the constant duration call. The period over which this change in call duration occurred differed for each of the four pairs of speakers. The numbers of females captured at the speaker array over the breeding season indicated that the most likely assessment time was close to 2 min. This estimate is similar, but not identical, to that obtained from additional laboratory tests.
Working with Dr. Per V. Brüel
Authors: Gade Kjær Svend
Published: October 2013

For more than a decade I have had the pleasure to work as an application specialist together with—and for—Dr. Brüel, one of the founders of the Brüel & Kjær Company, famous for sound and vibration measurement instrumentation, often nicknamed ‘‘Green Boxes.’’ It has been a great experience for me, and I recall this period in my life as one where I was much inspired by Dr. Brüel’s methods, both as a private person and with his work as a director for the company and leader of both the sales and the innovation departments. In this presentation I will highlight some funny stories that are told about Dr. Brüel combined with the episodes that I have experienced myself. In short, the most simple way to characterize this rather complex person is maybe by repeating his vision statement for the company: ‘‘We shall have fun and we shall make money. On the other hand we shall not have so much fun that we do not make any money, and we shall not make so much money that we do not have any fun!’’ For Per Brüel, acoustics is one of his great hobbies. He has others such as cars, airplanes, motorbikes (he is the lucky owner of a Danish Nimbus) and wine.
Musical instruments of Brazilian capoeira: Historical roots, symbolism, and use
Authors: Ilari Beatriz
Published: October 2013

This paper describes the historical roots, symbolism, and uses of musical instruments in capoeira. A martial art form of Afro-Brazilian origin, capoeira is rhythmically performed to music in a roda (i.e., circle). Capoeira is at times defined as a martial art form disguised as dance because it is rooted in the struggles of African slaves. Elements of music, dance, fight, and ritual are part of this unique martial art form, which has two main styles: Angola and Regional. Capoeira styles are important as they determine rhythmic patterns, chant, movement, and musical instrumentation in a roda. The leading instrument in all capoeira styles is the berimbau. The instrument dictates the rhythm and movement of capoeira players in a roda (Ilari, 2001). Made out of a wooden stick, a wire, and a gourd and played with a stick and a coin, the berimbau is considered a sacred instrument due to its association with the cry of the slaves. Other instruments used in capoeira are pandeiros, agogo bells, reco-recos, and atabaques. A discussion regarding the use of these instruments within the context of capoeira will be presented at the conference. The incorporation of these instruments into contemporary Brazilian music will also be considered.
Samba and the other sambas: Instrumentation in different forms of Brazil’s main musical genre
Authors: Majlis Pablo , Ilari Beatriz
Published: October 2013

The aim of the present paper is to describe the instruments of the different forms of samba, their origin, and their uses, focusing on percussion instruments. Samba is a Brazilian popular genre that developed mainly during the 20th century, though being deeply rooted in the precedent centuries of colonization and metissage between the Portuguese colonizers and the Africans that were brought as slaves. From its origins to the present day, samba has branched into multiple forms and instrumentation. Perhaps the most famous samba form is the samba enredo. This type of samba accompanies the Carnival parade in Rio de Janeiro, and features hundreds of percussionists. Another possible samba group instrumentation can be as simple as a single voice and a matchbox played by the singer. Between these two extremes there are several possible formations for a samba group, depending on the social context and function in which it occurs. Different group formations sometimes imply different song forms. Examples include samba de roda (i.e., circle samba), samba de gafieira (i.e., ballroom samba), and samba-cancao (i.e., samba ballad), among others. Some instruments will be available for attendees to try during the conference.
Validation–comparison of predicted and measured levels in industrial spaces
Authors: Probst Wolfgang
Published: October 2013

Financed by the German Federal Agency for Labor and Social Affairs, several methods of calculating the noise propagation in industrial halls were used for about 150 halls and compared with measurements. With all noise sources, such as machines and equipment stopped, a dodecahedron loudspeaker emitting broadband noise was used, and the octave-band levels were measured on different propagation paths. The room geometry and equipment in the room were entered into uniform datasets, the calculation methods were applied to each dataset, and the results in terms of deviations between calculated and measured values were evaluated statistically. The prediction method with the smallest deviations was chosen for further evaluation. This method, which uses mirror images with approximations and takes into account diffraction with a method first developed by Kuttruff and extended by Jovicic, uses mean values for fittings and absorption at walls and ceilings. This method has been incorporated into VDI 3760, and will be extended in the future to take into account screening by single objects and the real distribution of absorptive materials on surfaces. Representative experimental results, calculation techniques, predicted levels, and deviations between measured and predicted levels are presented.
Acoustically-driven spherical implosions and the possibility of thermonuclear reactions
Authors: Gaitan D. Felipe , Tessien Ross A. , Mead William C.
Published: October 2013

Acoustically driven, gas-filled cavities in liquids have been known to collapse violently, generating short flashes of light of ∼100 psec duration. This phenomenon has been known as Sonoluminescence (SL) and was first observed by Marinesco et al. in 1933. Ten years ago the author pioneered a technique for observing the oscillations of a single, gas-filled cavity (termed Single-Bubble Sonoluminescence) which has provided new insights into the phenomenon of sonoluminescence. More recently, the possibility of generating fusion reactions using acoustics has been considered. Results of computer simulations and preliminary experimental data will be presented. Back-of-the-envelope calculations in terms of the acoustical and thermodynamic parameters necessary to achieve Thermonuclear reactions will be presented in an effort to evaluate the feasibility of Sonofusion as an energy source.
Phase velocity measurements in a bubble swarm using a fiber optic sensor near the bubble resonant frequency
Authors: Cheyne Stanley A.
Published: October 2013

Acoustic phase velocity measurements of a bubble swarm in a cylindrical tube have been made with a fiber optic sensor. The fundamental design of this system is similar to one used in a previous experiment [S. A. Cheyne et al., ‘‘Phase velocity measurements in bubbly liquids using a fiber optic laser interferometer,’’ J. Acoust. Soc. Am. 97, 1621 (1995)]. This new system is more robust and is more easily constructed than the previous system. Results will be presented that will show conclusively that data have been obtained just after the bubble resonance in the regime where the attenuation of sound is very high. Other results will be presented at different air-to-water ratios (void fraction).
Time-scales for quenching single-bubble sonoluminescence in the presence of alcohols
Authors: Guan Jingfeng , Matula Thomas
Published: October 2013

A small amount of alcohol added to water dramatically decreases the light intensity from single-bubble sonoluminescence [Weninger et al., J. Phys. Chem. 99, 14195–14197 (1995)]. From an excess accumulation at the bubble surface [Ashokkumar et al., J. Phys. Chem. 104, 8462–8465 (2000)], the molecules evaporate into the bubble interior, reducing the effective adiabatic exponent of the gas, and decreasing the bubble temperature and light output [Toegel et al., Phys. Rev. Lett. 84, 2509–2512 (2000)]. There is a debate as to the rate at which alcohol is injected into the bubble interior. One camp favors the notion that molecules must be repetitively injected over many acoustic cycles. Another camp favors the notion that most quenching occurs during a single collapse. An experiment has been conducted in order to resolve the debate. Quenching rates were measured by recording the instantaneous bubble response and corresponding light emission during a sudden increase in pressure. It was found that complete quenching in the presence of methanol requires over 8000 acoustic cycles, while quenching with butanol occurs in about 20 acoustic cycles. These observations are consistent with the view that quenching requires the repetitive injection of alcohol molecules over repetitive acoustic cycles.