bluuebunny/crossref_metadata_2025 huggingface dataset:
Detection of environmental sounds in informative backgrounds.
Authors: Gygi Brian
Published: October 2010

In Gygi and Shafiro (2010), it was shown that the identifiability of environmental sounds presented in naturalistic scenes can be affected by the semantic content of the background scene: under certain conditions there is an incongruency advantage for sounds which are contextually incongruent, i.e., not semantically consistent with the background scene. Detection thresholds for the same set of sounds and scenes were obtained using adaptive tracking. The 28 background scenes were common auditory settings, such as a street scene or a restaurant. The 194 individual target sound tokens represented 50 distinct sound sources (e.g., baby crying, whistle blowing, etc.) and were presented in scenes that were both congruent and incongruent. The results show a wide range of detection thresholds, from ∼−10 to ∼−35 dB sound to scene ratio. These were overall much lower than detection thresholds for a similar corpus of sounds in broadband noise in Gygi et al. (1998), showing that naturalistic backgrounds can allow for greater detectibility; however, there was no significant difference between the thresholds in the congruent and incongruent settings, indicating that, unlike for sound identification, the semantic fit of the sound and scene was not a major feature in the detectibility.
The importance of syllable position and combination in the perception of birdsong by budgerigars (Melopsittacus undulatus).
Authors: Neilans Erikson G. , Welch Thomas E. , Maddox Ross , Shinn-Cunningham Barbara G. , Dent Micheal L.
Published: October 2010

Identifying a target signal in a clamorous environment is crucial for any social species. The current study examines the importance of syllable position for birds identifying a target song embedded in a chorus of masking noise. Four budgerigar subjects were trained for food reinforcement to identify three separate target zebra finch songs from a chorus masker of multiple simultaneous zebra finch songs. Following training, the birds identified individual syllable and incremental syllable stimuli as either target or masker by pecking the corresponding key. The early syllables in these songs elicited more “target” responses compared to the later syllables, suggesting that the beginning syllables are more salient in the perception of birdsong by these birds. Further, the sequential combination of syllables resulted in a gradual increase in target bird song responses, when syllables were added from beginning or end, indicating that as more of the song is presented, the ability to hear and identify the birdsong improves. These results indicate that the perception of birdsong by budgerigars follows similar rules as the perception of speech in humans.
Speech-in-speech recognition: Phonetic distance and semantic content.
Authors: Brouwer Susanne , Van Engen Kristin , Calandruccio Lauren , Bradlow Ann
Published: October 2010

Previous research has shown that monolingual English listeners receive a release from informational masking if the competing speech is foreign-language versus native-language noise [e.g., Van Engen & Bradlow (2007)]. This study examines whether speech-in-speech recognition varies even across typologically close target and noise languages (English versus Dutch) as well as across variation in the semantic content of the masker (meaningful versus semantically anomalous sentences) and the listener status (native versus nonnative listeners). The English and Dutch listeners’ task was to repeat target sentences in noise. The results for the Dutch listeners on Dutch targets showed a release from masking in English versus Dutch noise and in semantically anomalous versus meaningful sentences. Unexpectedly, the results for both listener groups on English targets only showed a release from masking for English anomalous noise relative to all other conditions. However, after normalization of the long term average spectrum of all noise, the results with English targets also showed a release from masking in foreign-language noise and in semantically anomalous sentences. Taken together, these speech-in-speech recognition studies show that linguistic masking involves interference at the acoustic-phonetic and the semantic levels. Moreover, the listener’s native or nonnative status influences the size of the release from masking.
Development of software-based simulation platform for hearing aid.
Authors: Wu Chao-Min , Syu Yong-Jie , Lin Po-Hsun
Published: October 2010

The purpose of this research is to develop a software-based simulation platform for hearing aid and to provide an assistive tool for clinician. User can experience hearing aid function and choose suitable hearing aid via the hearing aid simulation platform. The platform contains microphone input, noise reduction, wide dynamic range compression (WDRC), and feedback cancellation. The main purpose of this study was to simulate noise reduction and feedback cancellation by using patent documents of GN ReSound Canta, Sonic Innovation Natura, and Oticon Syncro. We evaluated the noise reduction efficiency by using subjective quality evaluation (waveform, spectrogram, listening) as well as objective quality evaluation (segmental SNR, log-spectral distance). The result shows that speech quality, signal to noise ratio, and listening comfort were improved. We also simulated feedback signals with KEMAR feedback path impulse responses and showed the three simulated feedback cancellation algorithms in good performance. Finally, we combined three noise reduction methods and WDRC with the three feedback cancellation methods of the same companies. The result shows that the effects of noise and feedback were both reduced efficiently.
Priming effect of hearing-impaired listeners in speech perception.
Authors: Han Woojae , Singh Riya , Allen Jont
Published: October 2010

Unlike normal hearing (NH) listeners, the speech perception of hearing-impaired (HI) listeners is much too complicated to be determined for certain. That is, HI listeners provide a varied profile of consonants that NH listeners record as 100% correct, with an error of less than 1/1000. Thus, we argue that there is an important factor that dominates the consonant errors in HI listeners: grouping errors, or priming. We hypothesize that when a cochlear dead region is present, a critical cue is lost, forcing priming errors (the listener cannot identify the sound within a group). We have tested over 50 sensorineural hearing-impaired ears for consonant recognition both in quiet and in noise. Sixteen English CV syllables were analyzed. Preliminary results showed that there is a subject based trend for either temporal or spectral cue errors when explaining the priming pattern of HI ears. In particular, /ga/, /ba/, /Za/, and /sa/ were reported as /da/, /pa/, /Sa/, and /Ta/, respectively. Although more data collection and analysis will be needed to prove the current findings, we conclude that HI listeners hear the consonant feature differently from NH listeners. [Work supported by NIH Research Grant.]
Generalization of learning in pre-lexical adjustments to word-final devoicing.
Authors: Eisner Frank , Weber Andrea , Melinger Alissa
Published: October 2010

Pre-lexical representations of speech sounds have been to shown to change dynamically through a mechanism of lexically driven learning. [Norris et al. (2003).] Here we investigated whether this type of learning occurs in native British English (BE) listeners for a word-final stop contrast which is commonly de-voiced in Dutch-accented English. Specifically, this study asked whether the change in pre-lexical representation also encodes information about the position of the critical sound within a word. After exposure to a native Dutch speaker’s productions of de-voiced stops in word-final position (but not in any other positions), BE listeners showed evidence of perceptual learning in a subsequent cross-modal priming task, where auditory primes with voiceless final stops (e.g., [si:t], “seat”) facilitated recognition of visual targets with voiced final stops (e.g., “seed”). This learning generalized to test pairs where the critical contrast was in word-initial position, e.g., auditory primes such as [taun] (“town”), facilitated recognition of visual targets like “down”. Control listeners, who had not heard any stops by the speaker during exposure, showed no learning effects. The results suggest that under these exposure conditions, word position is not encoded in the pre-lexical adjustment to the accented phoneme contrast.
Simulation of a model of the basilar membrane in two dimensions for Spanish vowels.
Authors: Jiménez Hernández Mario , Oropeza Rodríguez José Luis , Suarez Guerra Sergio
Published: October 2010

The inner ear has the cochlea as the principal element; this is a biological element in the form of a snail, within which the mechanical energy is converted into electrical energy. This process is realized by the inner ear cells on the basilar membrane. This membrane response is different for different frequencies of excitation; the result of this process is the human audition. This paper shows a simulation of a model in two dimensions of the basilar membrane and its characteristic response when excited by the tow first formants of Spanish vowels; these formants are obtained by an analysis by mixtures of Gaussians.
Gaussian wavelet functions modulated for audible response of the human ear.
Authors: Oropeza Rodriguez Jose Luis , Suarez Guerra Sergio
Published: October 2010

One of the most important aspects related with automatic speech recognition (ASRs) systems is to find a set of characteristics that represent speech signal; nowadays, LPC, CLPC, cepstrum, MFCC, LFCC, and Melspec, among others, have been used to solve that problem. Likewise, analyzing the audible behavior of the ear has shown to have good performance in comparison with those methods that consider the pronunciation as element to obtain speech signal representation. In this paper an analysis related with Gaussian wavelets representation based on Bark and Mel audible representations is presented. For these wavelets, a Gaussian function represents the basis decomposition function; further, we need a modulator to displace the function associated with each of the scales of analysis to the central frequency into Bark and Mel audible representations. At the same time, we use the variance parameter of the Gaussian function to adapt its bandwidth to the Bark and Mel audible representations. Finally, we show a comparison between two alternatives in time and frequency representations.
Three-dimensional scattering from the ocean surface using finite elements.
Authors: Joshi Sumedh M. , Isakson Marcia J.
Published: October 2010

Scattering from the ocean surface is a major parameter in propagation, reverberation, and coherence length models for shallow water waveguides. However, there are few models that quantify the effects of out-of-plane scattering at the ocean surface. In this work, a finite element model is used to quantify the effects of out of plane scattering by comparing 2-D models to those in three dimensions for given realizations of the ocean surface. The ocean surface roughness is described by an ocean surface spatial spectrum and the scattering of a Gaussian tapered plane wave is considered. Results for several different ocean surfaces are compared to the Kirchhoff approximation to determine its range of validity. [Work sponsored by the Office of Naval Research, Ocean Acoustics.]
Reverberation and backscatter at very small grazing angles.
Authors: Williams Kevin L. , Tang Dajun
Published: October 2010

Reverberation in shallow waters can be generally considered as a combination of two-way forward scatter and a single backscatter. With increasing range, reverberation consists of backscattered signals at ever smaller grazing angles. First-order perturbation theory is a suitable choice to model boundary roughness scatter if the rms roughness height is small compared to the acoustic wavelength. With decreasing grazing angle, the first-order theory works even better. To apply the first-order approximation, a zeroth-order problem is assumed known, which is often conveniently chosen to be the case where the boundary is flat. However, if the boundary has a low-wavenumber component, the flat boundary assumption for the zeroth-order field can result in modeling error. To quantitatively assess such error, perturbation results are compared to exact numerical solutions using COMSOL. It is found that such errors are found when grazing angles are on the order of a few degrees, because at such small grazing angles the true local grazing angle is sensitive to variations of the local boundary slopes.
Archaeoacoustics: Suggestions for a methodological framework.
Authors: Medina Andrés , Padilla Pablo , Alegre Lizette , Caro Guadalupe , Ramos Alejandro , Ruiz Tonatiuh , Zalaquett Francisca
Published: October 2010

We attempt to present a unified approach to archaeoacustics: its basic questions and methods, as well as the interaction of the several disciplines involved in this subject (archaeology, physics, engineering, mathematics, musicology, etc.) focusing on the role of the contribution of each of them. We illustrate with specific examples from pre-Colombian buildings in Mesoamerica what, from our point of view, might be called a working methodological framework. Our aim is to provide a general framework for archaeacoustical studies in which anthropological aspects are taken into account, together with scientific and technical issues that involve the formulation of mathematical and physical models, performing experiments, and so on. Within a global formulation, we argue that discussing general problems such as intentionality or functionality of certain buildings can be better addressed.
Ethnomusicology and musicology, a dialogue: Aproaching interdiscipline research in Mexican archaeoacustics.
Authors: Alegre Lizette , Caro Guadalupe
Published: October 2010

Recently, ethnomusicology and musicology, scientific disciplines of music, share not only a study object, but also have begun a dialogue about methodology, approaches, and theorical frameworks, which have benefited both musical disciplines, expanding their epystemological and analytic horizons. This dialogue empowered a better colaboration, in an interdisciplinary way, with other academic fields, such as archaeoacustics. This work presents how the work of this musical discipline may have contributed to the archaeoacustical work and investigations, by the objective review and análisis from different perspectivas such as ethnografic and historiografic análisis and appreciation of sources, iconographic análisis, inter alia. It will approach archaeoacoustic methodology, from the ethnomusicology and musicology perspective.
Acoustic study and reforcement of the temple of the sixteenth century (San Pedro Xalostoc).
Authors: Becerra García Jorge , Ramírez Rangel Patricia Lorena , Flores Martínez Joel
Published: October 2010

In the Laboratory of Psychoacoustics of the Zacatenco IPN-ESIME-ICE Zacatenco studies of acoustic answer to an enclosure of the XVI century of Franciscan extraction were carried out. The opposing results revealed that the acoustics presented inside the enclosure is quite capricious since the form was truly deliberate for the projection of the word and the musical sounds of that time.
Marine life detection and tracking using a swimmer detection sonar network.
Authors: Edson Patrick , Stein Peter J. , Rotker Nicholas A.
Published: October 2010

There is a growing need for real-time monitoring of marine life and floating debris during a wide variety of commercial operations. These include seismic exploration for oil and gas, explosive removal of offshore structures, pile driving for the installation of marine structures including offshore wind farms, and the operation of tidal turbines and wave power generation devices. Active acoustics is likely the best method for monitoring where there is a high-danger region with a limited range around the activity. The SSI Swimmer Detection Sonar Network was originally designed as a human swimmer and diver detection and tracking system. However, extensive trials have demonstrated that the system is also capable of tracking marine life ranging from a large fish or marine mammals to schools of smaller fish. Analysis of the detection characteristics and movement behavior of marine life is being conducted as a means of tracking and classification at ranges out to roughly 500 m. Real-time identification and tracking over time may also provide insight into the habituation of marine life to these facilities in addition to serving as a protective measure. [Research supported by ONR SBIR.]
Intensity fluctuations dominated by horizontal refraction during a strong nonlinear internal wave event.
Authors: Dossot Georges A. , Miller James H. , Potty Gopu R. , Smith Kevin B. , Lynch James F. , Lin Ying-Tsong , Badiey Mohsen
Published: October 2010

During the Shallow Water 2006 (SW06) experiment, a J-15 acoustic source deployed from the Research Vessel Sharp transmitted broadband (100–500 Hz) chirp signals 15 km away from a vertical line array. The array was intentionally positioned near the shelf-break front and in an area where internal waves are known to occur. During the same time an internal wave, “Event 44,” passed through the sound field such that the internal wave front was near parallel to the acoustic transmission path. Measured data show substantial intensity fluctuations that vary over time and space due to complex multimode and multipath (both 2- and 3-D) interference patterns. This presentation compares 3-D modeling results using the experimental geometry, acoustic signal parameters, and a simulated oceanographic environment based on environmental moorings and ship-born sensors to mimic the measured internal wave event. A modified version of the 3-D Monterey-Miami parabolic equation (MMPE) code which incorporates a user-defined sound speed field is used. Measured and modeled intensity fluctuations are compared during dominating horizontal regimes such as refraction, ducting, and “anti-ducting.” Modal-dependent time-arrival analysis during the different horizontal regimes is examined. [Work sponsored by the Office of Naval Research.]
Horizontal interference structure of the sound field in the presence of moving internal waves and estimation of angle of horizontal refraction.
Authors: Katsnelson Boris , Grigorev Valery , Badiey Mohsen , Lynch James
Published: October 2010

The experimental results of Shallow Water 2006 experiment (SW06) and theoretical estimations of the key parameters are presented for observation of non-stationary interference pattern provided by “direct” and reflected acoustic signals (acoustic Lloyd mirror effect) in shallow water. Propagation of low-frequency LFM chirp signals with the center frequency of 300 Hz and the bandwidth of 30 Hz on an acoustic track of about 20 km was studied. Refraction in the horizontal plane is caused by the wave front of the nonlinear internal waves (NIWs) moving across the acoustic track. Analysis of the non-stationary interference pattern on the horizontal and vertical line arrays and theoretical estimations give the angle of horizontal refraction (angle between direct and reflected rays) and the velocity of NIW. Results of estimations are in a good agreement with experimental data. [Work supported by ONR.]
Focusing with time reversal of speckle noise.
Authors: Robert Jean-Luc , Fink Mathias
Published: October 2010

The FDORT method (French acronym for decomposition of the time reversal operator using focused beams) is a time reversal based method that can detect point-scatterers in a heterogeneous medium and extract their Green’s function. It is particularly useful when focusing in a heterogeneous medium. In this presentation, the theory of the FDORT method is generalized to random media (speckle), and it is shown that it is possible to extract Green’s functions from speckle signal using this method. Therefore it is possible to achieve a good focusing even if no point scatterers are present. Moreover, a link is made between FDORT and the Van Cittert Zernike theorem. We deduce from this interpretation that the normalized first eigenvalue of the focused time reversal operator is a well-known focusing criterion. The concept of an equivalent virtual object is introduced, which allows the random problem to be replaced by an equivalent deterministic problem and leads to an intuitive understanding of FDORT in speckle. Applications to aberration correction are presented. The reduction of the variance of the Green’s function estimate is discussed.
Manipulation of diamond nano-particles using bulk acoustic waves.
Authors: Raeymaekers Bart , Pantea Cristian , Sinha Dipen
Published: October 2010

In this paper we investigate using the acoustic radiation force associated with a bulk acoustic standing wave to manipulate 5 nm diamond nano-particles in a user-defined pattern. Both concentric and rectangular patterns are studied and experimental results are compared to existing models. The effect of drag force acting on a nano-particle is evaluated and limits for particle speed and particle size that can be moved by acoustic radiation force are defined. We found good agreement between our experimental results and existing models and show that nano-sized particles can be manipulated by means of an acoustic radiation force.
Multidomain ferroelectric actuator.
Authors: Klymko Victor , Nadtochiy Andriy , Sedorook David , Ostrovskii Igor
Published: October 2010

An improved performance of a multidomain PZT actuator compared to a single domain actuator is demonstrated. The multidomain actuator is fabricated out of a 650-μm-thick single domain plate. The internal electric field is inverted by applying 1 kV/mm external electric field to 1/3 of the plate area. The remaining 2/3 of the area is left with the original internal electric field. The actuator is excited by applying 1 kV ac voltage to the electrodes deposited on the top and bottom surfaces of the plate. The amplitude of acoustical displacement at the tip of the actuator is calculated with the aid of a finite element model developed for the piezoelectric plate. In an experiment, the amplitude of tip vibration is measured under the microscope. The experimental resonance frequencies are consistent with the calculations. At the second order resonance, the calculations predict 25% higher amplitude of vibrations for the multidomain actuator than for the single domain actuator. The results for several actuators with different configurations of ferroelectric domains are compared to the single domain actuator.
Poly (ã-Benzy; á,L glutamic acid)-based piezoelectric film microfibers.
Authors: Farrar Dawnielle , West James E. , Yu Michael S. , Moon Wonkyu
Published: October 2010

Composite films and microfibers based on the biopolymer poly(ã-benzyl á,L-glutamate) (PBLG) and their fabrication and piezoelectric properties are presented. By simultaneous poling and curing of PBLG/methylmethacrylate, we fabricated a flexible composite film with approximately 20% of the PBLG molecules oriented normal to the film surface exhibiting (d33 = 20 pC/N), and its Young’s modulus was 1 GPa. In an effort to optimize net dipole orientation in PBLG, we produced piezoelectric microfibers (diameter: 100 nm) with nearly all of the PBLG dipoles oriented along the fiber axis, evidenced by x-ray diffraction. The PBLG fibers showed high piezoelectricity (d33 = 32 pC/N) and an elastic modulus of 570 MPa. Both the piezoelectric film and fiber systems can be fabricated directly from solution in a mold or on a substrate. Due to the versatility in the fabrication process and the high piezoelectricity, these materials show great promise as transducer materials.
Musical acoustics as a general education course.
Authors: Morrison Andrew C.
Published: October 2010

Musical acoustics is a highly interdisciplinary field of study, drawing elements from music, physics, psychology, engineering, architecture, computer science, and electronics. As such, a course in musical acoustics for non-science majors is an ideal option for a general education science course with laboratory at many colleges and universities. Students with a predisposition against science courses may be more willing to engage in an acoustics class if they perceive that the course will overlap with their interest in music. An overview of a typical course in musical acoustics will be presented. A summary of topics, classroom demonstrations, laboratory activities, and active learning techniques will be presented.
A brief history of the undergraduate acoustical engineering programs at the University of Hartford.
Authors: Vigeant Michelle C. , Celmer Robert D.
Published: October 2010

Located in West Hartford, CT, the University of Hartford’s undergraduate mechanical engineering program has had required coursework in acoustics and vibrations for over 40 years. The evolution of two undergraduate degree programs with a focus in acoustics will be discussed: (1) the Bachelor of Science in Mechanical Engineering (BSME) with Acoustics Concentration and (2) the interdisciplinary Bachelor of Science in Engineering (BSE), Acoustical Engineering & Music, which requires acceptance into the University’s music conservatory, The Hartt School. The programs provide both theoretical instruction on the concept of acoustics and vibrations as an inherent element of engineering design, and the benefits of applied, sponsored full-semester design projects. The program has evolved to incorporate real-world projects during the sophomore (second) year of the 4-year program, in addition to the well-established design project coursework during senior (fourth) year. A description of the acoustic and vibration facilities and equipment used by our students will be given, in addition to the results of a recent ABET accreditation visit.
Estimation of reed flow signal from instrument performance.
Authors: Smyth Tamara , Abel Jonathan S.
Published: October 2010

In this work we present a technique for estimating the reed flow signal, typically a periodic sequence of pulses, from the recorded sound of a reed instrument. The instrument is modeled as a reed coupled to a 1-D waveguide having unknown filter elements that must first be determined before constructing the instrument reed flow transfer function. As pressure waves make two round trips from the mouthpiece to the bell and back for each reed pulse, the output periodic pressure has two distinct halves: the second half being roughly the first half filtered by the instrument’s propagation losses. Estimation of these losses is not simply a spectral ratio, as the two halves are not temporally disjoint and the beginning of the reed pulse period is often unclear. The running autocorrelation of the recorded signal is zero phase and naturally provides the beginning of the period of the recorded signal as well as clear first and second phases that may be analyzed to estimate the round-trip losses in the instrument. Combining these losses with the direct measurements of the bell reflection function, a filter is developed which inverts the implied waveguide to produce the reed flow estimate.
Negative refraction and focusing of backward propagating Lamb waves.
Authors: Philippe Franck D. , Clorennec Dominique , Murray Todd W. , Prada Claire
Published: October 2010

It is known that some Lamb modes referred to as backward-waves have a negative phase velocity. In this work, the mode conversion between a forward and a backward Lamb wave is observed at the interface formed by a stepped thickness change and on a finite bandwidth around the frequency where the dispersion curves of the forward propagating mode S2 and the backward propagating mode S2b on opposite sides of the interface intersect. To this end, a linear array of transducers connected to a fully programmable electronic device is used to generate selectively the S2 Lamb mode in the thick part of the plate. The resulting surface displacements are detected using a heterodyne interferometer. We observe that the forward S2 mode propagating in the thick part is converted into the S2b mode in the thinner part. We demonstrate that such mode conversion leads to wave focusing across the interface as originally predicted by Veselago for negative index optical media.
Squeal acoustic emissions and the stick-slip effect.
Authors: Patitsas A. J.
Published: October 2010

The origin of the squeal acoustic emissions when a chalk is rubbed on a blackboard, or better on a ceramic plate, and those when a wet finger is rubbed on a glass surface is sought in the stick-slip effect between the two surfaces. The elastic agency that determines the frequency of the stick-slip process is sought in a thin shear band between the two surfaces, characterized by a very low shear modulus. In the case of the squealing chalk, the shear band is a layer of chalk powder, about 0.3 mm thick, forced to slide over the ceramic plate surface. Similarly, in the case of the wet finger, the shear band is a water layer forced to slide over the glass surface. The stick-slip resonance effect becomes coupled to the mode, in the shear band, characterized by high stability and by an anti-node of the particle displacement at the sliding interface. The application of such concepts to the acoustic emissions from singing (sand) grains impacted by a rod will also be discussed.
Thermoacoustic prime mover for thermal management.
Authors: Symko Orest G. , Rodriguez Ivan A. , Flitcroft Myra
Published: October 2010

Because thermoacoustic prime movers can operate over a wide range of temperature differences across the stack, they can be used in thermal management applications. Depending on their geometry and frequency of operation, the onset temperature differences for oscillation can vary by a few hundred degrees. This is attractive for low-temperature difference applications, as in computers and electronics, and for high-temperature differences as in power plants and automotive industry. Thermoacoustic devices developed here for the mid-audio frequency up to the ultrasonic range require special materials for the stack, heat exchangers, resonators, and assembly components. A critical issue is the thermal coupling of the acoustic device to the source of heat; it is based on mechanical contact and thermal compounds. The above development led to a variety of small thermoacoustic engines, which ranged in size from 5 cm down to a few millimeters in length. An important benefit of the above approach is that the devices can generate electricity by means of piezoelectric elements; this provides energy conversion from heat to sound to electricity. The working fluid is air at 1 atm.
Low-cost thermoacoustic co-generator for biomass-burning cook stoves.
Authors: Montgomery Paul J. , Garrett Steven L.
Published: October 2010

Three billion people cook daily on an open fire or primitive stove that creates so much pollution that it has been shown to be directly responsible for 1.6×106 deaths each year, almost exclusively among women and young children. Atmospheric models suggest that black carbon and methane released during biomass combustion are also the primary anthropogenic contribution to global warming from the populations of Southeast Asia, sub-Saharan Africa, and India. Recent research demonstrates that fan-aided combustion creates a significant decrease in products of incomplete combustion that degrades indoor air quality and exacerbates global warming. The use of a fan also increases efficiency, improves fuel flexibility, and reduces cooking times. Unfortunately, 1.6×109 biomass burners have no access to electricity, yet each cook stove produces 4–8 kW of heat. This presentation will describe a very simple co-generator prototype that extracts a small fraction of the stove’s heat and uses air at atmospheric pressure in a lumped-element, stack-based, thermoacoustic engine to vibrate an inexpensive moving-coil electrodynamic loudspeaker acting as a linear alternator that can generate the few watts of electrical power necessary to operate the fan and charge a battery. [Work supported by Paul S. Veneklasen Research Foundation.]
A comparison of suprasegmentals and segmentals in Indian English, Hindi, and Telugu.
Authors: Sirsa Hema , Redford Melissa A.
Published: October 2010

Indian English (IE), an official language of India, differs suprasegmentally and segmentally from other English dialects. This study explores whether IE sound structure varies with the divergent L1s of its speakers, as suggested by Wiltshire and Harnsberger (2006), or whether its sound structure is similar regardless of speakers L1. To investigate this question, measures of rate, rhythm, and final lengthening were taken in Hindi (Indo-Aryan), Telugu (Dravidian), and in IE, which was produced with native fluency by the same five Hindi and five Telugu speakers. Vowel and obstruent segments, common to all languages, were also extracted from the 13 stimulus phrases and acoustically analyzed. The results indicate some influence of the different L1s on IE rhythm structure and VOT, but none on IE speech rate, final lengthening, or vowel and /s/ production. Mostly, the results indicated that when language differences did exist (and there were many similarities across the languages), these were more likely to be between Hindi and IE or between Telugu and IE or between Hindi and Telugu than between the IE produced by speakers of different L1s. Such results suggest that IE is a pan-India dialect of English, not merely an L1 influenced L2 for Indians.
Function word facilitate word segmentation.
Authors: Kim Yun Jung , Sundara Megha
Published: October 2010

Infants’ word segmentation is facilitated by bottom-up cues, such as prosodic cues (stress-patterns, position in a sentence, etc.). Research shows that infants also use top-down cues, i.e., known words, to segment new words [Bortfeld et al. (2005); “mommy” and the child’s name]. In two experiments, infants were tested on their ability to use a known function word “the” to segment vowel-initial words (the ability to segment them does not appear until 13.5–16 months), without any additional bottom-up cues. In experiment 1, using the headturn preference procedure, monolingual English-learning 11-month-olds were tested on their ability to segment sentence-medial vowel-initial words that followed the function word “the.” First, infants were familiarized with passages containing the target words “ash” and “eff.” Next, infants were presented with two familiar and two novel isolated words. Mean listening time to the familiar and unfamiliar words was significantly different [t(12) = 4.220, p < 0.001]. Out of 13 infants, 12 listened longer to the familiar words compared to the novel words. In experiment 2, monolingual English-learning 8-month-olds are currently being tested using the same task. Preliminary results show three out of five 8-month-olds listen longer to the familiar words compared to the novel words.
Vocalic and consonantal processing biases in early word-learning: Cross-language differences?
Authors: Hojen Anders , Nazzi Thierry
Published: October 2010

Previous research showed that French-learning 16- or 20-month-olds could learn pairs of words that differed by a single consonantal but not vocalic feature. Danish has a richer vowel inventory than French, allowing for 31 phonological vowel contrasts, including vowel length and presence/absence of stod (laryngealization). The purpose of Experiment 1 was to test whether Danish-learning 20-month-olds, in spite of the importance of vowels in Danish phonology, showed a lack of sensitivity to one-feature vocalic differences in lexical learning similar to that of French-learning infants. The experiment made use of the same word-learning task as that used for French 16-month-olds. As opposed to the French-learning infants, the Danish-learning infants successfully learned the vowel pairs indicating sensitivity to small vocalic differences in word-learning. Experiment 2 tested the use of vowels in word-learning in French-learning 20-month-olds using the same task. They failed again. On the other hand, ongoing tests indicate that Danish-learning 20-month-olds, as opposed to French-learning 16- or 20-month-olds, fail to use one-feature consonantal differences in word-learning. These results may suggest that infants develop processing biases in word-learning depending on the sound-structure of their language. [Work supported by Widex A/S (A.H.) and Agence Nationale de la Recherche (T.N.), ANR-07-BLAN-0014-01 and ANR-09-FRBR-015.]
Speech discrimination of English, Spanish, and Mandarin consonants in monolingual and bilingual infants: An event related potentials experiment.
Authors: Garcia-Sierra Adrian , Ramirez-Esparza Nairan , Kuhl Patricia K.
Published: October 2010

The goal of this investigation was to compare speech discrimination in 11–14-month-old infants who are being raised in either monolingual English (N=22) or bilingual Spanish-English (N= 22) homes. The participants’ neural activity associated with the ability to discriminate English, Spanish, and Mandarin Chinese consonants was assessed using event related potentials (ERPs) in separate ERP sessions. The goal of the experiments is to compare ERPs for the phonetic units that infants have experienced as opposed to those they have never been exposed to. The native language neural commitment (NLNC) hypothesis holds that, by 11 months of age, infants respond differently to the phonetic units of native language(s) as opposed to non-native language(s). Comparisons between monolingual and bilingual infants should help resolve whether monolingual and bilingual infants are on the same timetable regarding NLNC. Our results will provide evidence about how early language exposure influences speech discrimination in monolingual and bilingual infants. [Work supported by an NSF Science of Learning Center grant to the UW LIFE Center.]
A chimpanzee (Pan troglodytes) recognizes spoken words synthesized as sine-wave speech.
Authors: Heimbauer Lisa A. , Beran Michael J. , Owren Michael J.
Published: October 2010

The human ability to understand speech in the absence of traditional acoustic cues to phonetic content has been argued to be evidence of specialized processing. To determine whether this capability is unique to humans, perception of sine-wave speech was examined in a 23-year-old, language-trained chimpanzee named Panzee. This animal was reared from infancy by human caregivers in a speech-rich environment and identifies more than 125 spoken words using graphical symbols (lexigrams). Test trials presented one of 48 familiar words via computer in either natural or sine-wave form, with Panzee choosing a corresponding lexigram from among four alternatives. Her performance on sine-wave words was well above chance levels, in spite of receiving no reward or any other feedback when responding to these sounds. The chimpanzee also showed above-chance accuracy on trials that cumulatively represented the first instances of hearing words in sine-wave form. While she was less accurate with sine-wave words than with natural versions, human listeners hearing the same stimuli were less accurate as well. Panzee’s performance indicates that experience with spoken language and general auditory-processing mechanisms alone can be sufficient for perceiving even highly impoverished synthetic speech.
Regional variation in vowel acoustics in children.
Authors: Jacewicz Ewa , Fox Robert Allen , Salmons Joseph
Published: October 2010

This study examines the acquisition of the American English vowel system by children who grew up in one of the three distinct dialect areas in the United States: western North Carolina, central Ohio, and southeastern Wisconsin. Of interest is the extent to which children acquire dialect-specific vowel dispersion patterns and dynamic formant movements (vowel-inherent spectral change). Ninety-four children (8–12 years) and 93 adults (51–65 years), males and females, produced 13 vowel categories in isolated hVd words. The results for children clearly show the presence of dialect-specific features found in adult speakers. The regional positional relations among vowels are generally maintained in children. For some vowels, the correspondence in the amount of spectral change and formant trajectory shape between children and adults is remarkable. Two major changes in children are common across dialects: reduction of formant movement in selected monophthongs and more uniform production of diphthongs in which dialectal differences present in adults tend to disappear. These results show that children are able to adopt and reproduce dialect-specific acoustic vowel characteristics quite well despite their exposure to highly variable input, which creates opportunities for dialect convergence and standardization through interaction with mass media and telecommunication. [Work supported by NIH.]
Diversity combining in time reversal communications.
Authors: Song Hee-Chun , Hodgkiss William S.
Published: October 2010

Time reversal exploits spatial diversity to achieve spatial and temporal focusing in complex environments and has been applied to underwater acoustic communications with a significant delay spread due to multipath propagation. Temporal focusing (pulse compression) mitigates the intersymbol interference (ISI), while spatial focusing achieves a high signal-to-noise ratio at the intended receiver. The time reversal approach can be combined with adaptive channel equalization to remove the residual ISI, providing nearly optimal performance in theory. The spatial diversity provided by a vertical array in a waveguide can be replaced by a single element and the temporal diversity provided by fluctuations of the ocean environment. Further, the relative motion between a transmitter and a receiver can provide both spatial and temporal diversity exploited in synthetic aperture communications. The diversity combining in time reversal communications will be illustrated using at-sea experimental data.
Underwater communication system.
Authors: Barroeta Carlos , Ortiz Floriberto R. , Novoa Colin Juan Francisco
Published: October 2010

When a pressure wave hits the sea bottom, or another object, reflected signal is transmitted back and is detected by the system. Transmission underwater is limited by frequency and other causes. Information lost can be measured in parameters like range, accuracy, and reliability. The sound radiated from a source is propagated in the water. The wave propagates in different directions and the sound intensity gets lower when the distance becomes larger. Water absorbs part of the energy from the wave due to absorption coefficient, and it is also affected by the distance. The wave has an axis beam with a high directivity index. A communication system based on this principle is presented.
The cardhouse theory of mud: Determination of shear wave speed.
Authors: Fayton Joseph O. , Pierce Allan D. , Carey William M. , Siegmann William L.
Published: October 2010

Platelets in high porosity ocean sediments carry negative charge due to isomorphous substitution. When immersed in an ion dense environment such as sea water, positive charges congregate near each surface. The high porosity combined with the charge configurations suggests a cardhouse structure where platelets repel face to face and attract face to end. Understanding the nature of interactions between platelet faces and edges is important for determining how the cardhouse responds to small amplitude acoustic disturbances. To quantify such interactions, a sequence of fundamental problems with electric charge distributions near and around charged platelets is considered, following general procedures of Verwey and Overbeek (1948). Analytical and computational results support a hinged joint model, for which the amount of energy required to separate perpendicular platelets is large compared to the energy required to rotate an edge about the contact line with another platelet. The implication is that mud will weakly resist shear, because the work done to achieve shear distortions results in an increase of electrostatic energy within the cardhouse. From the above considerations estimates of the shear bulk modulus and the shear wave speed are made. [Work partially supported by the ONR.]
Silenced sounds of a long gone past.
Authors: Bastos Patricia L.
Published: October 2010

The extended millenary galleries of rock art are among the pre-historical treasures in Portugal, a vast territory to explore. In search of the known but elusive proofs of music making, we have encountered specific types of ceremonial rocks that have been silent, with no memory of their use. For the first time, an approach has been made for studying the special 〈little holes rocks〉, or 〈rochas com covinhas〉, with an innovative systematic methodology. We are using a measuring-grid created for this purpose, an FFT analyzer, and digital recordings in two stages: (1) Acoustical analysis of the sound produced in the flat surfaces and in the holes, and comparison between the signals from different depths and shapes; (2) Observation, in the area, of the amplitude and repercussion of the formulated sound, recurring to readings in strategic positions surrounding the rocks. By attesting the musical exploitation of these pre-historical objects, there is an attempt to contribute to the understanding of how important was sound and its abstract organization in the development of the human race. Analytical charts, images, and recordings will illustrate the research here presented. [Work supported by Fundacao para a Ciencia e a Tecnologia, Portugal.]
Quantification of binaural acoustical conditions in elementary school classrooms.
Authors: Ronsse Lauren M. , Wang Lily M. , Powell Eric , Sim Paul
Published: October 2010

This study examines metrics calculated from binaural impulse response measurements conducted in more than 15 elementary school classrooms of a midwestern public school system in the United States. Binaural measurements were gathered in each room with the receiver located in four different positions. The source was located near the front of the room for each measurement in four different source azimuth rotations (0, 45, 90, and 180 deg from the receiver) to simulate a teacher facing different directions while speaking. The binaural metrics examined include interaural level differences, interaural cross-correlations, and differences in speech transmission index and frequency-to-frequency fluctuations between the two ears. The results of this research will document the binaural acoustical conditions of these spaces, supplementing previous work on acoustical parameters calculated from monaural impulse response measurements taken in elementary school classrooms [H. Sato and J. S. Bradley, J. Acoust. Soc. Am. 123, 2064–2077 (2008)]. The binaural metrics will also be correlated with measured background noise levels and reverberation times in the classrooms.
A binaural model to evaluate surround sound reproduction systems using head movements.
Authors: Braasch Jonas , Strong John T. , Xiang Ning
Published: October 2010

Recently, a binaural model was proposed, which utilized head movements to resolve front-back confusions [Braasch et al., J. Acoust. Soc. Am. 127, 1886]. Meanwhile, the binaural model has been extended to evaluate the benefit of surround loudspeakers for the reproduction of diffuse sound. For this purpose, two to four loudspeaker locations were simulated using head-related transfer functions (HRTFs). To simulate head movements, the HRTFs were adjusted in steps of 1 deg to maintain the loudspeaker positions in a room-related coordinate system. Uncorrelated white-noise bursts (1-s duration) were fed to each loudspeaker channel. The superposed spatialized signals were processed through a gammatone filter bank to measure coherence and interaural-level (ILDs) differences in individual frequency bands. Various loudspeaker configurations were tested. The study shows that coherence and ILDs for diffuse sound vary less with head movements if surround speakers (e.g., ±120 deg) are used in addition to a pair of front speakers (e.g., ±30 deg). For example, if the head is turned between ±40 deg, the maximum coherence drops from 0.58 to 0.39 if surround loudspeakers are added (600-Hz frequency band). At 5000 Hz, the maximum ILD magnitude is reduced from 10 to 4 dB with surround loudspeakers.