bluuebunny/crossref_metadata_2025 huggingface dataset:
The timbre model
Authors: Jensen Kristoffer
Published: October 2013

A timbre model is proposed for use in multiple applications. This model, which encompasses all voiced isolated musical instruments, has an intuitive parameter set, fixed size, and separates the sounds in dimensions akin to the timbre dimensions as proposed in timbre research. The analysis of the model parameters is fully documented, and it proposes, in particular, a method for the estimation of the difficult decay/release split-point. The main parameters of the model are the spectral envelope, the attack/release durations and relative amplitudes, and the inharmonicity and the shimmer and jitter (which provide both for the slow random variations of the frequencies and amplitudes, and also for additive noises). Some of the applications include synthesis, where a real-time application is being developed with an intuitive gui, classification, and search of sounds based on the content of the sounds, and a further understanding of acoustic musical instrument behavior. In order to present the background of the model, this presentation will start with sinusoidal A/S, some timbre perception research, then present the timbre model, show the validity for individual music instrument sounds, and finally introduce some expression additions to the model.
Piano string modeling: From partial differential equations to digital wave-guide model
Authors: Bensa J. , Bilbao S. , Kronland-Martinet R. , Smith Julius O.
Published: October 2013

A new class of partial differential equations (PDE) is proposed for transverse vibration in stiff, lossy strings, such as piano strings. While only second-order in time, it models both frequency-dependent losses and dispersion effects. By restricting the time-order to 2, valuable advantages are achieved: First, the frequency-domain analysis is simplified, making it easy to obtain explicit formulas for dispersion and loss versus frequency; for the same reason, exact bounds on sampling in associated finite-difference-schemes (FDS) can be derived. Second, it can be shown that the associated FDS is ‘‘well posed’’ in the sense that it is stable, in the limit, as the sampling period goes to zero. Finally, the new PDE class can be used as a starting point for digital wave-guide modeling [a digital wave-guide factors one-dimensional wave propagation as purely lossless throughout the length of the string, with losses and dispersion lumped in a low-order digital filter at the string endpoint(s)]. We perform numerical simulations comparing the finite-difference and digital wave-guide approaches, illustrating the advantages of the latter. We examine a procedure allowing the resynthesis of natural string vibration; using experimental data obtained from a grand piano, the parameters of the physical model are estimated over most of the keyboard range.
The syrinx: Nature’s hybrid wind instrument
Authors: Smyth Tamara , Smith Julius O.
Published: October 2013

Birdsong is commonly associated with the sound of a flute. Although the pure, often high pitched, tone of a bird is undeniably flutelike, its sound production mechanism more closely resembles that of the human voice, with the syringeal membrane (the bird’s primary vocal organ) acting like vocal folds and a beak acting as a conical bore. Airflow in the song bird’s vocal tract begins from the lungs and passes through two bronchi, two nonlinear vibrating membranes (one in each bronchial tube), the trachea, the mouth, and finally propagates to the surrounding air by way of the beak. Classic waveguide synthesis is used for modeling the bronchi and trachea tubes, based on the model of Fletcher [J. Acoust. Soc. Am. (1988, 1999)]. The nonlinearity of the vibrating syringeal membrane is simulated by finite-difference methods. This nonlinear valve, driven by a steady pressure from the bronchi, generates an oscillatory pressure entering the trachea.
Electrophysiological correlates of musical timbre perception
Authors: Caclin Anne , Brattico Elvira , Smith Bennett K. , Tervaniemi Mari , Giard Marie-Hilhne , McAdams Stephen
Published: October 2013

Timbre perception has been studied by deriving a multidimensional space of the perceptual attributes from listeners’ behavioral responses. The neural bases of timbre space were sought. First, a psychophysical timbre dissimilarity experiment was conducted. A three-dimensional space of 16 synthetic sounds equalized for fundamental frequency, loudness, and perceived duration was designed. Sounds varied in attack time, spectral center of gravity, and energy ratio of odd/even harmonics. Multidimensional scaling revealed a three-dimensional perceptual space with linear or exponential relations between perceptual and physical dimensions. Second, in an electrophysiological experiment, the mismatch negativity (MMN) component of event-related potentials was recorded. The MMN is elicited by infrequently presented sounds differing in one or more dimensions from more frequent ones. Although elicited without the focus of attention, it correlates with the subjects’ behavioral responses, revealing the neural bases of preattentive discrimination. Eight sounds were chosen within the perceptual space. Changes along individual and combined dimensions elicited an MMN response. MMN latency varied depending on the dimension changed. In addition, preliminary analyses tend to show an additivity of the MMN waves for some pairs of dimensions. These results shed light on the neural processes underlying the perceptual representation of multidimensional sounds. [Work supported by the CTI program of the CNRS.]
The effect of dissolved gas concentration on bubble-enhanced heating in tissue-mimetic materials
Authors: Yang Xinmai , Roy Ronald A. , Holt R. Glynn
Published: October 2013

Bubble-enhanced heating is a key mechanism to cause tissue damage in ultrasound surgery. We have conducted experiments in an agar-based tissue phantom. We found that the difference of air concentration in the tissue phantom has a small but measurable effect on the enhanced heating. Notably, high air concentration samples exhibit very good repeatability. We have passively monitored broadband acoustic emissions from the bubbles in order to determine if diagnostic information could be gleaned from such signals. Finally we investigate the effect of bubble size distribution on bubble-enhanced heating by employing bubble-based contrast agents to control the initial bubble size distribution. [Work supported by DARPA and the U.S. Army.]
Static and oscillatory response measurements of acoustically levitated foam drops
Authors: Liu Li , McDaniel J. Gregory , Holt R. Glynn
Published: October 2013

Small samples of aqueous foam of varying gas volume fraction are acoustically levitated in an ultrasonic field. The drops are subjected to both static and time-varying pressures. Normal mode frequencies and inferred rheological properties (yield stress, shear modulus) for foams as a function of gas volume fraction will be presented. We compare the experimental results to recent theoretical descriptions of such modal oscillations [McDaniel and Holt, Phys. Rev. E 61, 2204 (2000); McDaniel, Akhatov, and Holt, Phys Fluids 14, 1886 (2002)]. [Work supported by NASA.]
Transport parameters for pulsed ultrasonic waves propagating in an aluminum foam
Authors: Tourin Arnaud , Derode Arnaud , Mamou Victor , Fink Mathias , Page John , Cowan Michael L.
Published: October 2013

Aluminum foams have now been studied for many years in large part because of their applications as light-weight elastic materials (e.g., car bumpers, aerospace engineering applications). The pore size and the spatial distribution of the pores govern the mechanical behavior of the foam and can vary enormously depending on the method of manufacturing. Thus, new methods for the nondestructive characterization of these materials are needed. We present here a set of experimental ultrasonic methods in a range of frequencies where the ultrasonic waves are multiply scattered in the medium. In this regime, the propagation is described by ultrasonic transport parameters which are related to the microstructure of the foam. The diffusion coefficient and the absorption mean free path have been determined in pulse transmission experiments by fitting the solution of the diffusion equation to the average intensity, the so-called time of flight distribution. To more fully characterize the medium, the transport mean path and the diffusion coefficient have been measured in backscattering experiments using the static and dynamic coherent backscattering effects. For both methods, the properties of the sample interfaces have been taken into account.
Bubble dynamics in an acoustic flow field
Authors: Voronin Dmitry V. , Sankin Georgij N. , Mettin Robert , Teslenko Vyacheslav S. , Lauterborn Werner
Published: October 2013

Dynamics of interaction between cavitational bubbles is investigated when a complex of a compression and a rarefaction pulse passes through a liquid with pre-existing micro bubbles. Cavitation was generated experimentally with the help of electromagnetic generator of a flat and a convergent acoustic pulse (2-μs duration, 1–20 MPa) having the form of a hollow sphere segment. A modeling was performed within the frame of two-dimensional axisymmetric nonstationary approach on the basis of conservation laws for a model of an ideal compressible liquid. A thermodynamic flow field was computed both in liquid and inside bubbles. Behind the rarefaction wave the microbubbles begin to grow and generate secondary compression shocks, the amplitude of which may exceed that of the incident pulse under certain conditions. It is shown that the process of bubble interaction within a cluster is accompanied by bubble coalescence, fragmentation, and collapse of the initial bubble or its fragments. Simultaneously, high temperature spots appear in the bubble compressing by the secondary wave. Adiabatic heating of gas either inside a bubble or near the neck between a bubble and its fragment may result in sonoluminescence, also observed in experiments. [Work supported by ASA, DAAD, and RFBR.]
Attentional focus and the method of adjustment revisited
Authors: Watson Charles S. , Kidd Gary R. , Pok Soriya V.
Published: October 2013

In past reports we have described a technique by which listeners may be trained to focus their auditory attention on a particular spectral-temporal region of a complex acoustic stimulus, using the psychophysical method of adjustment. Previous work will be reviewed, and the results of a new experiment will be described, in which listeners were trained under both the adjustment method and a standard adaptive tracking technique to detect changes in the frequency of a tone within a nine-tone sequence. Under some circumstances, the adjustment procedure can enable listeners to learn to detect very small changes within a few minutes, whereas several hours of training under adaptive methods may be required to achieve the same detection or discrimination performance. Other differences between the two methods will be described. [Work supported by the NIH/NIDCD.]
Psychophysical analysis of sound and vibration in the cabin of passenger aircrafts
Authors: Mellert Volker , Baumann Ingo , Freese Nils , Kruse Roland , Weber Reinhard , Remmers Hermann , Bellmann Michael
Published: October 2013

The vibroacoustics within the fuselage of several types of aircrafts is recorded with microphones, ear-related devices, and accelerometers at different locations of passengers seats, and the workplace of the cabin and cockpit crew. The signals are analyzed according to standard psychoacoustic and vibration parameters. The requirements for the reproduction of the signals in a ground-based test-bed (e.g., mock-up) are identified. Results are reported on how well test facilities at ground meet real-flight conditions. [Work supported by the European Community (www.heace.org).]
Standardization of infrasounds and low-frequency noises for health benefits on humans
Authors: Damijan Zbigniew , Panuszka Ryszard , McGlothlin James
Published: October 2013

Annoyances from low-frequency noises and infrasound are effects of using technologies, transportation, manufacturing equipment, and large air-condition systems. Present developed procedures for evaluations of annoyance of low-frequency noise (LFN) on humans and occupational health are based on international and national standards. Comparisons show that there is a large difference between permitted values of acoustic pressure levels used. These standards are based on levels of thresholds heard by the human auditory system and subjective observations of impacts from vibrations of infrasound waves on the human body. A newly discovered phenomenon shows a follow-up effect in the brain and is an important reason to check and investigate attenuation of infrasound, especially near and below 10 Hz. Previous investigations showed that nonlinear reaction is observed according to the external infrasound field pressure on the human body. New studies need to investigate electrical reactions of the human brain and electrodermal reactions by influences of infrasound. [Work supported by the Kosciuszko Foundation, Inc., an American Center for Polish Culture, with Funding provided by the Alfred Juzykowski Foundation and KBN Warsaw.]
Artificial environment mapping from acoustic information
Authors: Martinez Rodolfo , Beristain Sergio
Published: October 2013

Living creatures have the capacity to build maps of the surrounding world from their hearing or ultrasonic perception systems. This mapping is generally assumed to allow survival within a complex environment. When this ability is applied to artificial life or artificial intelligence, the problem becomes very complex. This paper describes some reference models for several species.
Effect of envelope lowpass filtering on consonant and melody recognition
Authors: Lobo Arthur P. , Toledos Felipe , Loizou Philip C. , Dorman Michael F.
Published: October 2013

Recent work [Smith et al., Nature 416, 87–90 (2002)] has shown that the speech envelope contains fine temporal information which is used in pitch perception and spatial localization. This study was performed on normal hearing subjects. In this paper, we investigated the effect of lowpass filtering of the envelope on consonant and melody recognition in subjects using the Clarion cochlear implant. The subjects were originally fitted with the simultaneous analog stimulation (SAS) speech processing strategy, a strategy known to provide fine time-envelope information. The consonants and instrumental music were bandpass filtered into seven channels and the envelope of each channel was lowpass filtered with cutoff frequencies ranging between 100 and 1200 Hz. Initial results on the consonant recognition task showed that some subjects performed equally well for all envelope cutoff frequencies. On the melody recognition task, some subjects performed best at a particular envelope cutoff frequency. Results for the full set of subjects who participated in this study will be presented. [Work supported by NIH.]
Mechanical realization of passive scalar transfer functions
Authors: Dupont Pierre E. , Chen Wenyuan
Published: October 2013

There are typically an infinite number of mass-spring-damper systems that share the same input–output characteristics as described by a drive-point accelerance (passive) transfer function. The realization problem of solving for one or more of these mechanical systems arises in several application areas. These include the scaled acoustic testing of complex ship systems as well as the design of mechanical filters. The theory for scalar transfer functions involving no damping or proportional damping is well known. The family of solutions includes realizations consisting of masses connected entirely in parallel or in series; and algorithms are available for computing the components values. The assumption of proportional damping is purely for mathematical convenience, however, and does not usually concur with the reality of experimental data. This talk addresses the mechanical realization problem for scalar accelerance transfer functions with arbitrary viscous damping. A time domain approach is utilized to obtain a parameterized description of the solution set. Numerical methods are presened which can be used to search the solution set for realizations satisfying criteria relating to ease of fabrication, e.g., involving the fewest components. Laboratory experiments are included to validate the approach. [Work supported by ONR.]
Causes and consequences of the unequal distribution of vowels in the vowel space
Authors: Ladefoged Peter
Published: October 2013

A set of possible vocal tract shapes for vowels was generated, using a vocal tract model that operates in terms of the two tongue shape parameters determined by Harshman, Ladefoged, and Goldstein (1975) and one parameter of lip opening. Each of the tongue shape parameters was varied through 15 equal steps. Many of the combinations of the two parameters produced impossible distortions of the tongue or tongue shapes associated with consonants, but 147 of the 225 vowel shapes were humanly possible. These are 147 equally spaced vocal tract shapes as defined by the two parameters. Each of these tongue shapes was combined with seven degrees of lip rounding. When the first two formants of these 1029 vowels were plotted, some parts of this formant space are more densely populated than others. There are few vowels with low F1 and low F2. The difference among front vowels, such as those in heed, hid, head, had, can be made simply by varying the vocal tract shape, but the back vowels, such as those in hawed, hood, who’d, require added lip rounding. In the world’s languages there is often an asymmetry in the height of front and back vowels.
Realization of the English [voice] contrast in F1 and F2.
Authors: Moreton Elliott
Published: October 2013

Before a [voice] coda, F1 is higher for monophthongs but lower for /aI/ than before [+voice]. We test the hypothesis that this is due to local hyperarticulation before voiceless obstruents. Experiment 1, with 16 American English speakers, found the /aI/ pattern of more peripheral F1 and F2 in the offglides /oI eI aU/ as well, showing that it is part of the realization of [voice] rather than a historical property of /aI/. Some of the F2 increase in /aI oI eI/ cannot be accounted for by articulatory raising alone, but must be ascribed to fronting. The diphthong nuclei tended to change in the same direction as the offglides. Experiments 2 and 3, each with a different 16 American English speakers, collected ‘‘tight’’-‘‘tide’’ (Exp. 2) or ‘‘ate’’-‘‘aid’’ (Exp. 3) judgments of a synthetic stimulus in which offglide F1, offglide F2, and nuclear duration were varied independently. ‘‘Tight’’ and ‘‘ate’’ responses were facilitated by lower F1, by higher F2, and by shorter nuclei. Log-linear analysis showed that the three factors contributed independently, and that F2 was a stronger cue than F1 in terms of logits per Bark. Thus [voice] is correlated with, and cued by, peripheralization of diphthong offglides.
Influence of formant transitions and linguistic relevance on vowel imitation
Authors: Vallabha Gautam K , Tuller Betty
Published: October 2013

Speakers are unable to imitate the formants of isolated self-produced vowels accurately. The pattern of bias directions cannot be ascribed solely to articulatory or perceptual noise, and is different for each speaker [G. K. Vallabha and B. Tuller, J. Acoust. Soc. Am. 110, 2657 (2001)]. The present experiment examines whether the bias pattern persists when the vowels are embedded in a CV syllable. A dialectically uniform group of male and female American English [AE] speakers produced vocalic sounds in three conditions: (1) they read a list of /hVd/ words 10 times each, (2) they imitated /V/ and /dV/ targets containing monophthongal AE vowels and (3) they imitated /V/ and /dV/ targets that were systematically distributed over the F1×F2 space. All targets were self-produced (hence perfectly reproducible in principle) and were imitated 10 times each. Results will be discussed in terms of the bias and variability of AE versus non-AE targets, the imitation bias of /dV/ vs /V/ targets, and whether the bias pattern differences among subjects are reduced by the dialect uniformity. [Work supported by NIMH.]
Context effects on the perception of vowel spectral properties
Authors: Kiefte Michael , Kluender Keith R.
Published: October 2013

Previous studies [M. Kiefte and K. R. Kluender, J. Acoust. Soc. Am. 57, 55–62 (2001)] have shown that long-term stationary spectral characteristics have a very strong influence on the perception of specific cues in monophthongs. For example, F2 will be perceptually neglected if a precursor sentence is filtered by a one-pole filter corresponding to the center frequency and bandwidth of the target vowel. The present work continues this research and presents results from experiments using nonspeech precursors. The first set of experiments use speechlike stimuli that have been LPC vocoded from a time-reversed sentence having similar spectro-temporal properties to natural speech. The second set of experiments use FM-formant glides as precursors to test multiple hypotheses including the time course of these effects over varying precursor durations. The second set of experiments also test the hypothesis that the duration of the precursor plays a role in the magnitude of the context effect on the perception of the following vowel.
Lexical duration effects in Japanese function particles
Authors: Shirai Setsuko
Published: October 2013

It is well known that the lexical status, i.e., content versus function, influences vowel quality and duration in English. However, it is not clear if function particles in Japanese are reduced in a way that is equivalent to English. Previous studies [for example, N. Campbell, in Speech Production and Linguistic Structure, 1992] point out that Japanese particles tend to be long because of phrase-final lengthening effects and that function particles and content words tend to have different segmental content. Therefore, any study of the reduction in function particles must control for word and phrase position and must compare segmentally matched tokens. In this study function particles containing three vowels, [e, a, o], are compared with equivalent syllables in content words controlling for segmental context, the number of syllables, and for word and phrase position. For example, a content word [kiga] is matched with a token containing a function particle [ki-ga]. For 11 speakers of Tokyo Japanese, there was a significant effect for lexical category [F(1, 426), p<0.01]. When split for vowel, [a] maintained a significant effect, while the other two vowels only maintained a trend towards reduced duration in function particles.
Temporal characteristics of Chinese-accented English: Preliminary findings
Authors: Smith Bruce L. , Bradlow Ann R. , Bent Tessa
Published: October 2013

This study investigated several temporal features of English to determine the extent of their occurrence in the speech of talkers of Chinese-accented English who had relatively limited experience with spoken English. Specifically, the extent to which these speakers produced the following temporal contrasts was examined: (1) tense versus lax vowel duration, (2) vowel duration before voiced versus voiceless consonants, and (3) vowel and consonant duration in sentence-final versus nonfinal position. Preliminary data from sentences produced by eight non-native and eight native talkers indicates that the native English speakers and the Chinese-accented talkers did not differ in the extent to which they realized the inherent duration difference between tense and lax vowels. However, the native English subjects tended to show substantially greater vowel lengthening before voiced versus before voiceless consonants than the Chinese-accented talkers. In addition, while the two groups did not differ significantly in the extent to which they lengthened sentence-final consonants relative to nonfinal consonants, the native English talkers showed greater sentence-final vowel lengthening than the Chinese-accented talkers. When group differences for a given temporal parameter were found, 1 or 2 of the non-native subjects typically fell within the range of performance shown by the native speakers.
Duration and rate effects on American English vowel identification by native Danish listeners
Authors: Gottfried Terry L. , Bohn Ocke-Schwen
Published: October 2013

Native listeners alter their identification of American English vowel contrasts according to speaking rate, apparently making judgments about the relative duration of vowels. Berman et al. [J. Acoust. Soc. Am. 105, 1402 (1999)] created a series of spectral continua (varying F1 and F2) from ‘‘beat’’ to ‘‘bit,’’ ‘‘pat’’ to ‘‘pet,’’ and ‘‘cot’’ to ‘‘cut,’’ also varying syllable duration according to natural speech endpoints. These syllables were inserted into natural speech sentence contexts of two rates (normal and fast). Berman et al. found that longer syllable duration led to more long vowel (‘‘beat,’’ ‘‘pat,’’ ‘‘cot’’) responses; faster rate contexts also led to more long vowel responses. In the present research we tested native speakers of Danish on their use of duration and rate context in identifying these English vowels. Danish listeners were significantly affected by the duration of syllables in their vowel identification. However, despite vowel duration being phonemic in Danish, native Danish listeners were not significantly affected by rate context in their identification of these English vowels. This might be explained by perceived sufficiency of spectral information in these English vowel contrasts for Danish listeners, or by the lack of rate dependent vowel processing in their native language. [Work supported by Danish-American Fulbright Commission.]
On the relationship between perception and production of American English vowels by native speakers of Japanese: A pair of case studies
Authors: Nishi Kanae , Rogers Catherine L.
Published: October 2013

In a previous study, 15 American English (AE) vowels in /hVd/ words recorded by native speakers of Japanese (J) were presented in pairs to native speakers of AE. From these data, native-perceived vowel spaces of J-accented AE were obtained (Nishi, 2001). In the present study, two male native speakers of Japanese who had served as speakers in the previous study listened to the 15 AE vowels produced by two male native speakers of AE in a similarity rating task. Their perceptual data were analyzed using multidimensional scaling. J-perceived vowel spaces of AE vowels produced by AE speakers were compared to AE-perceived vowel spaces of J-produced AE vowels. Vowels produced by both AE and J speakers were also subjected to acoustic analysis. The acoustic vowel spaces obtained were then compared to the AE and J perceptual vowel spaces. Results revealed considerable differences between the two J speakers in terms of their perception of AE vowels. These differences were found to be strongly correlated with the speakers’ vowel spaces as perceived by AE listeners, as well as with their acoustic vowel spaces.
Improving English vowel perception and production by Spanish-speaking adults
Authors: Stenning Karen , Jamieson Donald G.
Published: October 2013

This study investigated the effects of perceptual and production training on the abilities of adult native speakers of Spanish to identify and produce the English vowels /i, I, e, ε, æ/. Testing was performed prior to and following an average of 12 h of perceptual training in a category inclusion task, then again following an average of 7.5 h of production training involving visual feedback of vowel formant (F1 and F2) values. A lagged control group of participants who were delayed in starting training showed no improvement in perception and production skills during the control period but changed equivalently during training. The mean improvement in perceptual identification accuracy for /i, I, e, ε/ was 17%. The mean improvement in the intelligibility of participants productions of /I, ε, æ/ following training was 11%. For both perception and production, most improvement occurred during perceptual training.
Effects of hearing status and perturbation with a bite block on vowel production
Authors: Vick Jennell C. , Perkell Joseph S. , Lane Harlan , Matthies Melanie , Zandipour Majid , Stockmann Ellen , Guenther Frank , Tiede Mark
Published: October 2013

This study explores the effect of hearing status on adaptation to a bite block in vowel productions of normal hearing (NH) adults and adults who use cochlear implants (CI). CI speakers are tested prior to and following experience with the implant. Different sized bite blocks (BB) are used to create unusual degrees of mandibular opening for vowel productions in an /hVd/ context (had, head, heed, hid, and hod). Four conditions are elicited from each NH and CI speaker: (1) no BB with hearing (CI processor on), (2) no BB with no hearing (NH speakers with masking noise and CI speakers with processor off), (3) BB with no hearing, and (4) BB with hearing. Prior to fitting with the implant, CI speakers are tested without hearing in two conditions: (1) no BB and (2) BB. Spectra of the vowel productions are analyzed for dispersion of tokens in the F1–F2 plane in the four conditions. Pilot results support the hypothesis that prior to fitting, CI users are less able to adapt to perturbations than NH speakers and that experience with a CI improves adaptation. The current study is exploring this result further with larger groups of subjects. [Research supported by NIH.]
Mothers exaggerated acoustic-phonetic characteristics in infant-directed speech are highly correlated with infant’s speech discrimination skills in the first year of life
Authors: Liu Hue-Mei , Kuhl Patricia K. , Tsao Feng-Ming
Published: October 2013

In addition to the well documented suprasegmental features of infant-directed speech, recent studies demonstrate that critical acoustic-phonetic features are exaggerated at the level of segments in infant-directed speech (IDS) [Kuhl et al. (1997); Liu et al. (2000); Burnham et al. (2002)]. The speech directed to infants contains acoustically more extreme vowels when compared to adult-directed speech, resulting in an expanded vowel space. The relationship between the exaggerated characteristics of IDS and infants’ speech perception skills has not previously been examined. The present study tested the hypothesis that there is a correlation between characteristics of speech input and speech perception sensitivity for individual infants in the first year of life. Thirty-two Mandarin Chinese mothers’ speech samples were recorded in infant-directed and adult-directed speech conditions. The acoustic analysis demonstrated that Mandarin mothers modify their speech when speaking to their infants, amplifying the important acoustic cues. More importantly, the acoustic-phonetic characteristics in a particular mother’s infant-directed speech are significantly correlated with her infant’s speech perception. This result supports the view that hyperarticulation of the phonetic units in infant-directed speech facilitates infant’s language development. [Work supported by NIH grant (HD37954) and Talaris Research Institute.]
Rhythmic patterns in the speech of developmental apraxia of speech and articulation-disordered children
Authors: Passadakes Maria , Bell-Berti Fredericka , Paoli Joanne , Gelfer Carole
Published: October 2013

Many disorders, particularly those of neurological origin, involve disturbances in timing control. Research on children’s speech is needed to better understand children’s acquisition of phonological processes, and how it goes awry. Studies investigating timing aspects of the speech of developmentally apraxic and articulation-disordered children are lacking. The purpose of this research is to describe both phrase-final lengthening and compensatory shortening patterns of apraxic and articulation-disordered children, as well as normal children, under 5 years old.
Guidelines for the acoustical conditioning of classrooms in educational buildings
Authors: Mastroizzi Jorge Alberto , Montes Carmen , Amura Susana , Mastroizzi Maria Amelia
Published: October 2013

The purpose of this work is to identify deficiencies in acoustical conditions within classrooms. Taking the classroom as a representative educational space, acoustical requirements will be determined as a function of the grade level of the students being taught. Sources of noise that affect the classrooms will be examined, assessed, and corrective measures proposed.
Shallow-water reverberation highlights and bottom parameter extractions from the STRATAFORM
Authors: Preston John R. , Ellis Dale D.
Published: October 2013

Together with SACLANTCEN, the authors recently participated in the Boundary Characterization Experiment to measure shallow-water bottom reverberation in the STRATAFORM off New Jersey. SUS charges were used as monostatic sources. The receivers were horizontal arrays. Data were analyzed in bands from 160–1500 Hz. The STRATAFORM is known to have benign surface morphology but contains many buried river channels. Highlights of the reverberant returns are discussed that include returns from over the shelf break. Some comparisons in reverberation characteristics between SUS and coherent pulses are noted. Another objective of these reverberation experiments was to quickly invert for bottom scattering and bottom loss parameters. An automated geo-acoustic parameter extraction method was used together with the Generic Sonar Model and a Jackson-Mourad model for scattering. After automatically adjusting bottom loss and scattering strength, good agreement is achieved between the diffuse reverberation data and model predictions in relatively flat areas. Model/data differences are generally correlated with bottom scattering features. Since reverberation typically lasts 10–20 s or more, extracted parameters apply over wide areas. Local bottom loss and backscattering measurements were made by Holland in these areas. A comparison with Holland’s results is given. [Work supported by ONR Code 32, Grant No. N00014-97-1-1034.]
Geoacoustic characterization of seabed scattering experiment locations
Authors: Osler John , Lock Blair
Published: October 2013

Measurements of acoustic forward and backscattering have been made by DRDC Atlantic during collaborative sea-trials on the Scotian Shelf off the coast of Nova Scotia and on the Strataform site off the coast of New Jersey. In this paper, the geoacoustic properties and roughness parameters that are necessary to interpret and model the scattering measurements are presented. They have been determined using complementary in situ and acoustic techniques. The in situ measurements have been made using grab samples and a free fall cone penetrometer that has been fitted with a resistivity module. The probe provides two independent means of calculating the undrained shear strength, an empirical sediment classification and sediment bulk density. The acoustic measurements include inversions for geoacoustic parameters using the WARBLE [Holland and Osler, J. Acoust. Soc. Am. (2000)] and normal incidence sediment classification [Hines and Heald, Proc. Inst. Acoust. (2001)] techniques. At the scattering experimental locations, these measurements have been combined with surveys using commercial equipment: sidescan sonar, multibeam bathymetry, and subbottom profilers to characterize the seabed.
Comparison of in situ compressional wave speed and attenuation measurements to Biot–Stoll model predictions
Authors: Kraft Barbara J. , Mayer Larry A. , Simpkin Peter G. , Goff John A.
Published: October 2013

The importance of estimating acoustic wave properties in saturated marine sediments is well known in geophysics and underwater acoustics. As part of the ONR sponsored Geoclutter program, in situ acoustic measurements were obtained using in situ sound speed and attenuation probe (ISSAP), a device developed and built by the Center for Coastal and Ocean Mapping (CCOM). The location of the Geoclutter field area was the mid–outer continental shelf off New Jersey. Over 30 gigabytes of seawater and surficial sediment data was collected at 99 station locations selected to represent a range of seafloor backscatter types. At each station, the ISSAP device recorded 65 kHz waveform data across five acoustic paths with nominal probe spacing of 20 or 30 cm. The recorded waveforms were processed for compressional wave speed and attenuation. Experimental results are compared to predicted values obtained using the Biot–Stoll theory of acoustic wave propagation. Several methods are examined to estimate the required model parameters. The contribution of loss mechanisms to the effective attenuation is considered. [Research supported by ONR Grant No. N00014-00-1-0821 under the direction of Roy Wilkens and Dawn Lavoie.]
Separation of scattering mechanisms for the Asian Sea International Acoustics Experiment East China Sea reverberation measurements
Authors: Dorfman Y. , Cable P. G. , Knobles D. P. , Yudichak T. W. , Zhang R. , Peng Z. , Li F. , Li Z. , Miller G. H. , Potty G. R.
Published: October 2013

Low-frequency monostatic reverberation data collected in the East China Sea on a VLA are analyzed to infer bottom scattering strength characteristics. The VLA was deployed and the data collected by researchers from the Institute of Ocean Acoustics, Beijing, China. Reverberation data originating from ranges from 3–15 km are analyzed using coherent array processing methods to determine scattering strengths as a function of frequency and angle at the scatterer. Subaperture processing is used to separate sea surface and bottom contributions and to gain physical insight into the scattering mechanisms responsible for the observed reverberation level. Modeled transmission loss obtained from analyses of measured forward propagation data is employed within the framework of the subaperture signal processing to enable the extraction of the scattering strength. [Work supported by ONR.]
The acoustics for speech of eight auditoriums in the city of Sao Paulo
Authors: Bistafa Sylvio R.
Published: October 2013

Eight auditoriums with a proscenium type of stage, which usually operate as dramatic theaters in the city of Sao Paulo, were acoustically surveyed in terms of their adequacy to unassisted speech. Reverberation times, early decay times, and speech levels were measured in different positions, together with objective measures of speech intelligibility. The measurements revealed reverberation time values rather uniform throughout the rooms, whereas significant variations were found in the values of the other acoustical measures with position. The early decay time was found to be better correlated with the objective measures of speech intelligibility than the reverberation time. The results from the objective measurements of speech intelligibility revealed that the speech transmission index STI, and its simplified version RaSTI, are strongly correlated with the early-to-late sound ratio C50 (1 kHz). However, it was found that the criterion value of acceptability of the latter is more easily met than the former. The results from these measurements enable to understand how the characteristics of the architectural design determine the acoustical quality for speech. Measurements of ST1-Gade were made as an attempt to validate it as an objective measure of ‘‘support’’ for the actor. The preliminary diagnosing results with ray tracing simulations will also be presented.
Three halls for music performance in Chile
Authors: Delannoy Jaime , Heuffemann Carolina , Ramirez Daniel , Galvez Fernando
Published: October 2013

The primary purpose of this work was to investigate about the present acoustic conditions of used architectonic spaces in Santiago of Chile for orchestras of classic music performance. The studied halls were three: Aula Magna Universidad de Santiago, Teatro Municipal de Nunoa, and Teatro Baquedano. The used methodology was based on studies made by L. Beranek, M. Barron, among others, in concert halls worldwide. As it guides, for the measurement procedure, physical parameters RT, EDT, C50, C80, LF, BR, G, U50 were evaluated according to norm ISO 3382. On the other hand, it has been defined, to proposal way, a questionnaire of subjective valuation directed to musicians, specialized conductors, and listeners.
Brazilian professional recording studios: Analysis and diagnostics of their acoustical properties
Authors: Passeri Lineu , Bistafa Sylvio R.
Published: October 2013

Acoustic measurements and design characteristics from a sample of Brazilian professional recording studios located in Sao Paulo and Rio de Janeiro will be presented and discussed. Noise levels, EDT (early decay time), RT20 and RT30 measured in the studios and control rooms will be presented and compared. From these results, the project solutions will be analyzed to check how each recording environment is compatible with its acoustical needs and with the contemporary recording technology. The main goal is to establish guidelines and objective acoustical parameters to be used in the design of new recording studios. (To be presented in Portuguese.)
Indoor acoustic gain design
Authors: Concha-Abarca Justo Andrés
Published: October 2013

The design of sound reinforcement systems includes many variables and usually some of these variables are discussed. There are criteria to optimize the performance of the sound reinforcement systems under indoor conditions. The equivalent acoustic distance, the necessary acoustic gain, and the potential acoustic gain are parameters which must be adjusted with respect to the loudspeaker array, electric power and directionality of loudspeakers, the room acoustics conditions, the distance and distribution of the audience, and the type of the original sources. The design and installation of front of the house and monitoring systems have individual criteria. This article is about this criteria and it proposes general considerations for the indoor acoustic gain design.
Environmental influences on anuran sound communication
Authors: Penna Mario
Published: October 2013

Studies of anuran vocal behavior in the South American temperate forest may represent the southernmost influence of Robert Capranicas comparative approach to sound communication. Vocalizations of leptodactylid frogs in this region exhibit patterns of propagation characteristic for different microhabitats. Calls containing frequencies above about 1 kHz experience higher attenuations in bogs as compared to marshes, irrespective of the species native environment. A similar lack of optimal relationships between signal structure and habitat properties for call propagation occurs in sound environments other than the temperate austral forest, as indicated by joint studies with colleagues from Cuba in Caribbean tropical forests and from Spain in European Mediterranean habitats. Anurans from southern Chile calling in bogs have peculiar acoustic adaptations: males call from burrows inside which the calls of neighboring cospecifics are amplified considerably. This effect potentially counteracts the constraints for signal propagation of sound-attenuating environments. The evidence presented indicates that anuran calls have not been subjected to environmental selection pressures, to the extent vocalizations of other vertebrates have. Dispersion of anurans is limited by availability of water sources, but males can choose locations favoring signal broadcast and reception in their relatively restricted breeding areas. [Work supported by FONDECYT Grant No. 1010569.]
Neural correlates of temporal pattern selectivity in anurans
Authors: Gerhardt H. Carl
Published: October 2013

Female anurans typically show strong phonotactic selectivity for synthetic signals having pulse-repetition (pulse) rates that are close to those in advertisement calls produced by conspecific males. Auditory neurons showing temporal selectivity for species-typical pulse rates (especially bandpass neurons) are commonly reported from the inferior colliculus and central nucleus of the auditory thalamus. However, a number of questions remain about the neural bases of temporal pattern selectivity. First, the proportion of neurons tuned to conspecific values varies enormously among species. Are these differences real or by-products of different methodologies? Second, behavioral studies indicate that some species do not evaluate the pulse rate per se but rather are selective to certain ranges of pulse duration and interpulse intervals. What is the role of bandpass (and other filter types) neurons in these species? Third, temporally selective neurons are often tuned to spectral peaks that are not emphasized in the advertisement call. Do these cells nevertheless play a role in temporal selectivity? Finally, recent studies indicate that extensive lesions of the auditory thalamus have little effect on phonotactic selectivity for conspecific pulse rates. What then is the role of temporally tuned neurons in this structure? [Work supported by NSF and NIH.]
Dynamic bimodal signal evokes fighting behavior in a dart-poison frog
Authors: Narins Peter M. , Hoedl Walter , Grabul Daniela S.
Published: October 2013

As a neuroethologist, Bob Capranica strongly encouraged his students to study animals in their natural habitat in order to truly understand the behavioral rules underlying acoustic communication. This study was one of many inspired by those lessons. Male anuran vocalizations serve to attract conspecific females and to regulate male spacing through territorial interactions. In response to playback of a conspecific call, some male frogs have been reported to alternate their call with the perceived stimulus or shift their call-dominant frequency to avoid acoustic interference, or add call notes to signal an increased state of aggression. In some species, males orient toward the sound source followed by physically approaching the loudspeaker. Although natural fighting behavior between conspecific males has been observed in the field, it has not heretofore been possible to elicit with loudspeakers broadcasting sounds. In this playback study of the Brilliant-thighed dart-poison frog (Epipedobates femoralis) in French Guiana, we used an electromechanical model to provide realistic bimodal cues (acoustic and visual) to calling males. Our data suggest that agonistic behavior could be evoked in territorial males only when both acoustic and visual cues were presented simultaneously. [Work supported by grants from NIH (PMN) and Austrian Science Foundation (WH).]
Forty years of solitude: Using laboratory lines of D. melanogaster to study behavioral isolation
Authors: Boake Christine R.
Published: October 2013

Population genetic models of speciation show that the initial population divergence can be very rapid when sexual signals are involved, and that speciation through sexual selection has a high probability compared to speciation through viability selection. The models also suggest that the exact nature of the changes in a signal system can be arbitrary. This raises empirical questions of whether behavioral divergence can be detected sooner than postzygotic isolation, and whether, in a multimodal signal system, certain signals are more likely to diverge than others. The early stages of behavioral isolation are being investigated by using stocks of D. melanogaster that have been in captivity for 40–50 years. Two lines that were part of a 1950s study of DDT resistance have begun to evolve behavioral isolation; however, postzygotic isolation is not detectable. The courtship signals of recently diverged populations can be compared to published reports of behavioral isolation between populations of D. melanogaster and between D. melanogaster and its close relative to learn whether signal divergence always follows the same trajectory.