bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of lag-time on dichotic word perception in children
Authors: Shoemaker Sheryl S. , Goshorn Edward L. , Jette Shannon
Published: October 2013

Dichotic word perception is an essential component in audiological test batteries that are designed to identify auditory processing disorders (APD). Lag-time is the time difference between onsets of dichotic stimuli. The contribution of lag-time to perception of dichotic speech is not fully known and there is a lack of data available on children. Studies by Black (1955) and Berlin et al. (1973) found intermittent effects of lag-time on perception of dichotic speech in adults. This project examined the effects of 3 lag-times (0, 150, and 300 ms) on perception of NU-CHCIPS [Elliot and Katz (1980)] words presented dichotically at 50 dB HL through ER-3A insert phones. The sequence of lag-times and ear order was balanced. Subjects were six children age 7 to 10 years who had normal hearing and normal findings on standardized APD tests. Lag-times of 0, 150, and 300 ms yielded mean error rates of 1.3, 1.5, and 1.7 ms, respectively. Mean right ear and left ear error rates were 1.4 and 1.6, respectively. A two-way ANOVA showed no significant (p>0.05) effect for lag-time, ear preference, or their interaction. Implications for findings and development of APD treatment materials based on lag-time data will be presented.
Effects of frequency shifts and visual gender information on vowel category judgments
Authors: Glidden Catherine , Assmann Peter F.
Published: October 2013

Visual morphing techniques were used together with a high-quality vocoder to study the audiovisual contribution of talker gender to the identification of frequency-shifted vowels. A nine-step continuum ranging from ‘‘bit’’ to ‘‘bet’’ was constructed from natural recorded syllables spoken by an adult female talker. Upward and downward frequency shifts in spectral envelope (scale factors of 0.85 and 1.0) were applied in combination with shifts in fundamental frequency, F0 (scale factors of 0.5 and 1.0). Downward frequency shifts generally resulted in malelike voices whereas upward shifts were perceived as femalelike. Two separate nine-step visual continua from ‘‘bit’’ to ‘‘bet’’ were also constructed, one from a male face and the other a female face, each producing the end-point words. Each step along the two visual continua was paired with the corresponding step on the acoustic continuum, creating natural audiovisual utterances. Category boundary shifts were found for both acoustic cues (F0 and formant frequency shifts) and visual cues (visual gender). The visual gender effect was larger when acoustic and visual information were matched appropriately. These results suggest that visual information provided by the speech signal plays an important supplemental role in talker normalization.
Part Ia: Spatial separation on McGurk effect applying three-dimensional sounds
Authors: Riederer Klaus A. J.
Published: October 2013

The dependence of sound direction on the McGurk effect [McGurk and McDonald, Nature (London) 264, 746–748 (1976)] is less known. Jones and Munhall [Canadian Acoust. 25, 13–19 (1997)] concluded with no spatial separation dependence, applying 30° horizontally spaced loudspeakers. Current dual study investigated the full 360° horizontal space applying head-related transfer functions (HRTFs) from a Cortex dummy head [Riederer, J. Audio Eng. Soc. (Abstracts) 46, 1036 (1998), preprint 4846]. Dry acoustic /ipi/ and /iti/ recorded from a professional speaker were convolved with HRTFs, measured at azimuths 0°, ±40°, ±90°, ±130°, and 180°, headphones (Sennheiser HD580) equalized. DVcam-recorded visual /ipi/, /iti/ (and black screen) were randomly presented synchronously with the 3-D sounds using Presentation 0.20 [http://nbs.neuro-bs.com]. Totally 1024 incongruent audiovisual stimuli were perceived by eight 20–30-year-old normal hearing (≤20 dBHL) native subjects (2 female) as follows. Visual /ipi/ + auditory /iti/: /ipi/ 59.96%, /iti/ 15.63%, and /ipti/ 24.02%; visual /iti/ + auditory /ipi/: 66.02%, 22.07%, and 11.52%, respectfully. No significant dependence of spatial separation was found for the McGurk effect, except for reaction times. The obtained fusions were atypically weak, probably because visual /iti/ was less pronounced than visual /ipi/. [Work supported by Graduate School of Electronics, Telecommunication and Automation.]
The time course of indexical specificity effects in the perception of spoken words
Authors: McLennan Conor T. , Luce Paul A.
Published: October 2013

This research investigates the time-course of indexical specificity effects in spoken word recognition by examining the circumstances under which the variability in the speaking rate affects the participant’s perception of spoken words. Previous research has demonstrated that variability has both representational and processing consequences. The current research examines one of the conditions expected to influence the extent to which indexical variability plays a role in spoken word recognition, namely the time-course of processing. Based on our past work, it was hypothesized that indexical specificity effects associated with the speaking rate would only affect later stages of processing in spoken word recognition. The results confirm this hypothesis: Specificity effects are only in evidence when processing is relatively slow. [Research supported (in part) by Research Grant No. R01 DC 0265801 from the National Institute on Deafness and Other Communication Disorders, National Institutes of Health.]
Some effects of intonation contour on sentence intelligibility
Authors: Hillenbrand James M.
Published: October 2013

This experiment was designed to measure the effects of pitch movement on sentence intelligibility. A source-filter synthesizer was used to generate three synthetic versions of 60 sentences drawn from the TIMIT multi-talker speech database: (1) an original pitch (OP) condition in which the fundamental frequency (F0) contour matched that of the original utterance, (2) a monotone pitch (MP) condition in which F0 was held constant at the median value measured from the original utterance, and (3) an inverted pitch (IP) condition in which the F0 contour was reflected around the median F0 value (i.e., pitch rises were changed to pitch drops, and vice versa). Results from 30 listeners showed a small but statistically reliable drop in intelligibility from the OP condition to either the MP or IP condition, with no difference between the MP and IP conditions. A second group of 22 listeners was tested on the same task, but with overall sentence intelligibility reduced by running all signals through a 2-kHz low-pass filter. As with the unfiltered signals, intelligibility was reduced for the MP and IP conditions relative to OP; however, the decrements in intelligibility were somewhat larger for the filtered signals, and inverting pitch caused a larger intelligibility decrement than flattening pitch.
Signal processing for aircraft flyover noise synthesis and propagation
Authors: Rizzi Stephen A. , Sullivan Brenda M. , Cook Bryan A.
Published: October 2013

Subjective assessments of low noise aircraft flight operations require time histories of acoustic pressure at listener positions. Synthesized sound has an advantage over recordings by allowing the examination of proposed aircraft, flight procedures, and other conditions or configurations for which recordings are unavailable. A two-stage process for synthesizing flyover noise at listener positions on the ground is presented. The first stage entails synthesizing time histories at the flying source. Rizzi and Sullivan [J. Acoust. Soc. Am. 113, 2245 (2003)] developed an approach for synthesizing sound from broadband sources (e.g., jet noise) based upon predicted 1/3-octave band source spectra. Further developments in source synthesis signal processing are presented here, including the introduction of temporal fluctuations and the synthesis of tone-dominated sources (e.g., fan noise). The second stage entails propagation of the synthesized sound from the flying source to the listener. Its signal processing aspects are also presented and include a dynamic absolute delay of sound and location (producing accurate Doppler shift and emission position), spreading loss, atmospheric attenuation, and binaural filtering. Whereas the first stage prediction analysis and synthesis are computed a priori, the second stage is performed in real-time, allowing creation of an immersive test environment.
Control of early and late energy in rooms with the variable room acoustics system
Authors: Poletti Mark , Ellison Steven
Published: October 2013

Many electroacoustic systems seek to offer control of subjective sound quality using either regeneration of sound or by minimizing feedback to produce in-line sound control. In-line systems provide control of early energy from the stage but do not respond globally to all sound sources. Regenerative systems offer global enhancement of late energy but are less able to influence early energy. The Variable Room Acoustics System is a hybrid approach which contains a regenerative system for reverberation enhancement and an in-line system for early energy control. Both systems are optimized to provide maximum power gain. The principles of the system are outlined and results from recent installations are presented.
Active field control (AFC) -electro-acoustic enhancement system using acoustical feedback control
Authors: Miyazaki Hideo , Watanabe Takayuki , Kishinaga Shinji , Kawakami Fukushi
Published: October 2013

AFC is an electro-acoustic enhancement system using FIR filters to optimize auditory impressions, such as liveness, loudness, and spaciousness. This system has been under development at Yamaha Corporation for more than 15 years and has been installed in approximately 50 venues in Japan to date. AFC utilizes feedback control techniques for recreation of reverberation from the physical reverberation of the room. In order to prevent coloration problems caused by a closed loop condition, two types of time-varying control techniques are implemented in the AFC system to ensure smooth loop gain and a sufficient margin in frequency characteristics to prevent instability. Those are: (a) EMR (electric microphone rotator) -smoothing frequency responses between microphones and speakers by changing the combinations of inputs and outputs periodically; (b) fluctuating-FIR -smoothing frequency responses of FIR filters and preventing coloration problems caused by fixed FIR filters, by moving each FIR tap periodically on time axis with a different phase and time period. In this paper, these techniques are summarized. A block diagram of AFC using new equipment named AFC1, which has been developed at Yamaha Corporation and released recently in the US, is also presented.
Experimental evaluation of the omnidirectional behavior of platonic polyhedron loudspeakers
Authors: Rollins Sarah , Leishman Timothy , Dix Gordon
Published: October 2013

Many architectural acoustics measurements require the use of an omnidirectional source. For several years, the source predominantly used for such applications has been the dodecahedron loudspeaker with small in-phase drivers mounted in each face. While other platonic polyhedron loudspeakers (PPLs) have not been used as frequently, they also produce nearly omnidirectional fields over limited bandwidths. Above cutoff frequencies specific to their geometries, all PPLs depart from ideal omnidirectional behavior, with varying degrees of directivity. While these cutoff frequencies are typically higher for higher-order polyhedra, they commonly fall within the bandwidths of standard measurements. The five types of PPLs have been constructed and measured to gain greater insight into their omnidirectional behaviors. Their frequency responses were taken at 2664 points over a sphere (5-deg polar and azimuthal angle increments) in an anechoic chamber. The measurements were then processed to produce directivity balloon plots. However, to better compare directivities and find the source consistently producing the most omnidirectional field over a useful bandwidth, a frequency-dependent standard deviation formula was implemented. Average values of the standard deviation parameter produce figures of merit that further characterize omnidirectionality. [Research supported by funding from the NSF REU program.]
Geoacoustic inversion of broadband data in the Florida Straits
Authors: Chapman N. Ross , Jiang Yongmin
Published: October 2013

Acoustic propagation experiments have been carried out in the Florida Straits with a multi-frequency broadband source that transmitted m-sequence pulses over a range of 10 km to a sparse-filled vertical line array. This paper presents results of matched field inversions of the acoustic field data at low frequencies to estimate geoacoustic model parameters for the experimental site. Two approaches were taken for the inversions. The first was a conventional matched field inversion using multi-frequency data centered at 200 and at 400 Hz from the vertical array. The second approach was designed to model the low frequency waveform at a single hydrophone. For the very long range experimental geometry, the waveform was modeled in terms of modes. Each inversion was cast as an optimization problem using the adaptive simplex simulated annealing algorithm. The inversions provide a comparison between approaches that take advantage of the spatial coherence in one case, and the time coherence in the received signal in the other case. Both inversions give similar results for the parameters of a simple geoacoustic bottom model, and the sensitivities and relative uncertainties of the model parameters are consistent for the two approaches. Notably, the inversions are sensitive to compressional wave attenuation.
Geoacoustic inversion results of low- to high-frequency source tow data from the ASIAEX East China experiment
Authors: Huang Chen-Fen , Hodgkiss William S.
Published: October 2013

During the 2001 ASIAEX East China Sea experiment, source tow data was collected by a 16-element, 75-m aperture, autonomously recording vertical line array in approximately 105-m-deep water. Transmissions from two similar 6-km-long tracks were transmitted. In the first, CW tonals at 95, 195, 295, 395, 805, 850, and 905 Hz were transmitted from a J-15 transducer at a nominal depth of 46 m. In the second, CW tonals at 1.6, 2.4, 3.5, and 4.4 kHz were transmitted from an ITC-2015 transducer at a nominal depth of 49 m. An environmental model in the study area initially was derived by matched-field geoacoustic inversion using the low-frequency track. In this study, the high-frequency data from the second track are included in the parameter assessment. A multiple-stage geoacoustic inversion scheme is applied. Inversion results for seafloor geoacoustic parameters from these transmissions will be presented. [Work supported by ONR.]
Numerical modeling of air-to-sea transmission of light aircraft noise
Authors: Giddens Eric M. , Buckingham Michael J.
Published: October 2013

Recent experiments at SIO have shown that the acoustic signature of a light aircraft can be detected by sensors in the water column as well as buried in the underlying sediment and a method for extracting the sound speed and attenuation from this Doppler shifted signal has been proposed. To test the accuracy of this geoacoustic inversion technique, a numerical model of the air-water-sediment acoustic propagation, including the effects of a high-speed airborne source, has been developed based on the spectral method. Simulated acoustic data have been generated representing an aircraft flying over a microphone in the atmosphere, a vertical line array in the ocean, and a hydrophone buried 1-m deep in the sediment. The results of the geoacoustic inversion for sound speed and attenuation are compared to the known input parameter values of the model, giving a sense of the relative errors that may be expected when applying the technique to experimental data. [Work supported by ONR.]
The effects of ignored seabed variability in geo-acoustic inversion
Authors: Lapinski Anna-Liesa S. , Chapman David M. F.
Published: October 2013

In recent years, acoustic inversion techniques have been developed to predict ocean environmental properties, source position, etc. However, when applying such techniques to measured acoustic data, assumptions are invariably made with respect to the parametrization of the ocean environment due to unavailable information or to simplify the problem. In this work, the influences of range-dependent variability of the seafloor in the results of inversion are explored. That is, a typical inversion algorithm is applied while making the assumption that all parameters of the ocean-bottom (e.g., compressional speed, water depth, density, attenuation) are constant with range when in fact one parameter varies realistically with range. The inversion algorithm is applied to many unique realizations of a synthetic ocean-bottom; however, for each realization, the nonfluctuating parameters remain constant and the statistics regarding the fluctuating parameter such as the mean parameter value and the standard deviation of the fluctuations about the mean remain the same. It is shown that ignoring the variation in even a single seabed parameter leads to significant and correlated uncertainty in all inverted parameter values.
Are buried river channels sources of geoclutter on the New Jersey Continental Margin?
Authors: Osler John C.
Published: October 2013

Geological features on a continental shelf may be responsible for anomalous acoustic scatter that are identified as (false) targets, or GeoClutter, on active sonar systems. Features on the New Jersey Continental Margin include a drainage system that formed when sea-level was much lower, ran across the shelf, and incised channels approximately 10 meters deep into the surrounding seabed. These channels have since been filled with sediments that are not apparent on bathymetric maps. The potential for these channels to create GeoClutter depends in part on the contrast in geoacoustic properties between the sediments filling the channels and the adjacent flanks. To study this matter, an experiment was conducted to measure the reflection loss from 1 to 10 kHz of channel fill and flank sediments in an area where GeoClutter has been observed and where there is supporting geophysical data. The measurements were made using the WARBLE technique [C. W. Holland and J. C. Osler, J. Acoust. Soc. Am. 107, 1263–1279 (2000)], adapted for use in rapid environmental assessment using modified sonobuoys. Results from the experiment will be presented and the role of buried channels acting as sources of GeoClutter on the New Jersey Continental Margin will be discussed.
Rapid continuous-wave pressure field calculations for spherically focused radiators
Authors: McGough Robert
Published: October 2013

A new accelerated expression for the continuous-wave pressure field generated by a spherically focused radiator is obtained when the impulse response formulation is transformed and optimized for numerical evaluations. The resulting integral expression converges much more quickly than the impulse response approach, resulting in far fewer function evaluations for the same numerical error. The optimized integral expression is between two and seven times as fast as the impulse response approach, where the increase in speed depends on the peak value of the specified error. In addition, this new result completely eliminates the cone-shaped regions required for impulse response calculations, so the resulting computer code for the accelerated expression is less complicated than the corresponding code for the impulse response. Results also show that the new expression eliminates the numerical artifact that is encountered near the boundary between regions defined for impulse response calculations. All of these features are useful in thermal therapy computer simulations that employ spherically focused transducer geometries.
Optimization of angular compounding in scatterer size estimation
Authors: Gerig Anthony L. , Chen Quan , Zagzebski James A.
Published: October 2013

Ultrasonic scatterer size estimates generally have large variances due to the inherent noise of the spectral estimates used to calculate size. Compounding partially correlated size estimates associated with the same tissue, but produced with data acquired from different angles of incidence, is an effective way to reduce the variance without making dramatic sacrifices in spatial resolution. This work derives theoretical approximations for the correlation between these size estimates, and between their associated spectral estimates, as functions of data acquisition and processing parameters, where a Gaussian spatial autocorrelation function is assumed to adequately model scatterer shape. Size results exhibit a fair degree of agreement with those of simulation experiments, while spectral results compare favorably with simulation outcomes. Utilization of the theoretical correlation expressions for data acquisition and processing optimization is discussed. Further simplifying approximations, such as the invariance of phase and amplitude terms with rotation angle, are made in order to obtain closed-form solutions to the derived spectral correlation, and permit an analytical optimization analysis. Results indicate that recommended parameter adjustments for performance improvement depend upon whether, for the system under consideration, the primary source of estimate decorrelation with rotation is scatterer phase change or field separation. [Work supported by NIH T32CA09206.]
Modes of vibration of air-driven free reeds in transient and steady state oscillation
Authors: Paquette Ammon , Vines Justin , Cottingham James P.
Published: October 2013

Most treatments of free reed oscillation approximate the reed vibration as a sinusoidal oscillation of a cantilever beam in the fundamental transverse mode, although some evidence of the presence of the second transverse mode has been reported. [Cottingham et al., J. Acoust. Soc. Am. 105, 940 (1999)]. Some new measurements of the oscillation of a free reed from an American reed organ mounted on a laboratory wind chest show that the second beam mode is present even at low amplitudes of oscillation, and is often observable in the transient period before the oscillation reaches full amplitude. Some evidence of higher frequency modes has also been observed. In addition to steady state oscillation, reed motion during two types of attack transients has been studied. In one case, with full playing pressure in the wind chest and air flowing through the reed, the reed is restrained in its unblown equilibrium position and suddenly released. In another configuration, the reed is provided with a pallet valve mechanism, and reed oscillation is initiated by a sudden rush of air when the valve is opened. [Work supported by the NSF from REU Grant No. 0139096.]
A loudness model in dichotic conditions
Authors: Ih Jeong-Guon , Cha Jeong-Ho
Published: October 2013

Existing loudness models are specified only to diotic sounds in spite of the fact that normal human beings hear dichotic sounds. The arithmetic mean of loudness values of both ear signals has been suggested for the approximated value of the resultant perceived loudness. In this study, the dependence of overall loudness perception on the interaural level differences was investigated by the subjective tests. It was found that the larger the interaural level difference, the louder the perception than the mean of calculated loudness values at both ears and the lower the critical band rate or the reference level, the louder the perception than the mean value. A modified loudness model was proposed for the application to dichotic sounds by using the equivalent diotic levels.
Environmental noise—a challenge for an acoustical engineer
Authors: Genuit Klaus
Published: October 2013

People live in a landscape full of noises which are composed of both natural environmental noises and technically created sounds. Regarding environmental noise, more and more people feel heavily annoyed by noises. Noise is defined as an audible sound which either disturbs the silence or an intentional sound listening or leads to annoyance. Thus, it is clearly defined that the assignment of noise cannot be reduced to simple determining objective parameters such as the A-weighted sound pressure level or the equivalent continuous sound pressure level. The question of whether a sound is judged as noise can only be made after the transformation from the sound event into an auditory event has been accomplished. The evaluation of noise depends on the physical characteristics of the sound event, on the psycho-acoustical features of the human ear, as well as on the psychological aspects of man. For the acoustical design of environmental noise and in order to create a better soundscape the acoustical engineer has to consider these aspects. That means a specific challenge for the sound engineering.
Sound quality descriptors for HVAC equipment from ARI Standards
Authors: Lind Stephen J.
Published: October 2013

The Air Conditioning and Refrigeration Institute (ARI) has several standards that provide methods to evaluate the sound quality of heating ventilating and air-conditioning (HVAC) equipment. These include Standard 270 Sound rating of outdoor unitary equipment, Standard 350 Sound rating of non-ducted indoor air-conditioning equipment, and Standard 1140P Procedures for evaluating sound quality of HVAC equipment. The preferred method in these standards is best described in Standard 1140P, which uses one-third octave band sound power levels that are weighted to adjust for the sensitivity to frequency distribution and presence of tones, and are then converted to a single number sound quality indicator. The tone adjustment is based on the projection of a given one-third octave band level relative to the average of the adjacent one-third octave bands. An alternate use of Zwicker method B to determine loudness and loudness level is also provided in ARI Standard 1140P. These standards provide a convenient method by which complex sounds for similar products may be compared.
Nonlinear modal methods for crack localization
Authors: Sutin Alexander , Ostrovsky Lev , Lebedev Andrey
Published: October 2013

A nonlinear method for locating defects in solid materials is discussed that is relevant to nonlinear modal tomography based on the signal cross-modulation. The scheme is illustrated by a theoretical model in which a thin plate or bar with a single crack is excited by a strong low-frequency wave and a high-frequency probing wave (ultrasound). A crack is considered as a small contact-type defect which does not perturb the modal structure of sound in linear approximation but creates combinational-frequency components whose amplitudes depend on their closeness to a resonance and crack position. Using different crack models, including the hysteretic ones, the nonlinear part of its volume variations under the given stress and then the combinational wave components in the bar can be determined. Evidently, their amplitude depends strongly on the crack position with respect to the peaks or nodes of the corresponding linear signals which can be used for localization of the crack position. Exciting the sample by sweeping ultrasound frequencies through several resonances (modes) reduces the ambiguity in the localization. Some aspects of inverse problem solution are also discussed, and preliminary experimental results are presented.
Front-to-rear movement of reverberation in a concert hall
Authors: Sacks Jonah , Kleiner Mendel
Published: October 2013

In some concert halls one can perceive a front-to-rear movement of late reverberation as noted by T. J. Schultz [J. Sound Vib. 43, 555–561 (1975)]. Listening tests show that the effect is not likely to be due to timbral change but rather to result from the spatial properties of the reverberant field. The effect can be noted as a change in late center time as a function of lateral angle of incidence of reverberant sound. The effect is likely to be a result of the scattering characteristics of hall surfaces. Measurements using a simplified scale model support this hypothesis. Measurements in Boston’s Symphony Hall yield similar results. [Work supported by RPI.]
Simulation of ultrasound propagation in bone
Authors: Kaufman Jonathan J. , Luo Gangming , Siffert Robert S.
Published: October 2013

Ultrasound has been proposed as a means to noninvasively assess bone and, particularly, bone strength and fracture risk, as for example in osteoporosis. Because strength is a function of both mineral density and architecture, ultrasound has the potential to provide more accurate measurement of bone integrity than, for example, with x-ray absorptiometric methods. Although some of this potential has already been realized—a number of clinical devices are presently available—there is still much that is unknown regarding the interaction of ultrasound with bone. Because of the inherent complexity of the propagation medium, few analytic solutions exist with practical application. For this reason, ultrasound simulation techniques have been developed and applied to a number of different problems of interest in ultrasonic bone assessment. Both 2D and 3D simulation results will be presented, including the effects of architecture and density on the received waveform, propagation effects of both cortical and trabecular bone, and the relative contributions of scattering and absorption to attenuation in trabecular bone. The results of these simulation studies should lead to improved understanding and ultimately to more effective clinical devices for ultrasound bone assessment. [This work was supported by The Carroll and Milton Petrie Foundation and by SBIR Grant No. 1R43RR16750 from the National Center for Research Resources of the NIH.]
Supplementary features for improving phone recognition
Authors: Balaraman Mridul , Dusan Sorin , Flanagan James L.
Published: October 2013

Traditional speech recognition systems use mel-frequency cepstral coefficients (MFCCs) as acoustic features. The present research aims to study the classification characteristics and the performance of some supplementary features (SFs) such as periodicity, zero crossing rate, log energy and ratio of low frequency energy to total energy, in a phone recognition system, built using the Hidden Markov Model Tool Kit. To demonstrate the performance of the SFs, training is done on a subset of the TIMIT data base (DR1 data set) on context independent phones using a single mixture. When only the SFs and their first derivatives (feature set of dimension 8) are used the recognition accuracy is found to be 42.96% as compared to 54.65% when 12 MFCCs and their corresponding derivatives are used. The performance of the system improves to 56.49%, when the SFs and their derivatives are used along with the MFCCs. A further improvement to 60.34% is observed when the last 4 MFCCs and their derivatives are replaced by SFs and their derivatives, respectively. These results indicate that the supplementary features contain classification characteristics which can be useful in automatic speech recognition.
Phoneme recognition with kernel learning algorithms
Authors: Namarvar Hassan H. , Berger Theodore W.
Published: October 2013

An isolated phoneme recognition system is proposed using time-frequency domain analysis and support vector machines (SVMs). The TIMIT corpus which contains a total of 6300 sentences, ten sentences spoken by each of 630 speakers from eight major dialect regions of the United States, was used in this experiment. Provided time-aligned phonetic transcription was used to extract phonemes from speech samples. A 55-output classifier system was designed corresponding to 55 classes of phonemes and trained with the kernel learning algorithms. The training dataset was extracted from clean training samples. A portion of the database, i.e., 65338 samples of training dataset, was used to train the system. The performance of the system on the training dataset was 76.4%. The whole test dataset of the TIMIT corpus was used to test the generalization of the system. All samples, i.e., 55655 samples of the test dataset, were used to test the system. The performance of the system on the test dataset was 45.3%. This approach is currently under development to extend the algorithm for continuous phoneme recognition. [Work supported in part by grants from DARPA, NASA, and ONR.]
Study of acoustic correlates associate with emotional speech
Authors: Yildirim Serdar , Lee Sungbok , Lee Chul Min , Bulut Murtaza , Busso Carlos , Kazemzadeh Ebrahim , Narayanan Shrikanth
Published: October 2013

This study investigates the acoustic characteristics of four different emotions expressed in speech. The aim is to obtain detailed acoustic knowledge on how a speech signal is modulated by changes from neutral to a certain emotional state. Such knowledge is necessary for automatic emotion recognition and classification and emotional speech synthesis. Speech data obtained from two semi-professional actresses are analyzed and compared. Each subject produces 211 sentences with four different emotions; neutral, sad, angry, happy. We analyze changes in temporal and acoustic parameters such as magnitude and variability of segmental duration, fundamental frequency and the first three formant frequencies as a function of emotion. Acoustic differences among the emotions are also explored with mutual information computation, multidimensional scaling and acoustic likelihood comparison with normal speech. Results indicate that speech associated with anger and happiness is characterized by longer duration, shorter interword silence, higher pitch and rms energy with wider ranges. Sadness is distinguished from other emotions by lower rms energy and longer interword silence. Interestingly, the difference in formant pattern between [happiness/anger] and [neutral/sadness] are better reflected in back vowels such as /a/(/father/) than in front vowels. Detailed results on intra- and interspeaker variability will be reported.
User expertise in speech centered multimodal human computer interaction
Authors: Chandrasekaran Rajesh , Dusan Sorin , Flanagan James L
Published: October 2013

Multimodal interfaces aim to permit natural communication by speech and gesture. Typically the speech modality bears the principal information in the interaction with gesture complementing spoken commands. A continuing challenge is how to correlate and interpret the simultaneous inputs to estimate meaning and user intent. User expertise and familiarity figure prominently in the interpretation. The present research studies the effect of user expertise on multimodal human computer interaction. Users are classified into experienced and inexperienced depending on the amount of their exposure and interaction with multimodal systems. Each user is asked to perform simple tasks using a multimodal system. For each task the automatically recognized speech input is time stamped and the lag or lead of the gesture input is computed with respect to this time stamp. The time interval around the time stamp in which all the users’ gesture inputs occur is determined. For experienced users this interval averages 56.9% less than that for inexperienced users. The implication is that for experienced users the spoken input are the corresponding gesture input are more closely related in time than for inexperienced users. This behavior can be exploited in multimodal systems to increase efficiency and reduce time of response for the system.
Differences in directional sound source behavior and perception between assorted computer room models
Authors: Vigeant Michelle C. , Wang Lily M. , Rindel Jens Holger
Published: October 2013

Source directivity is an important input variable when using room acoustic computer modeling programs to generate auralizations. Previous research has shown that using a multichannel anechoic recording can produce a more natural sounding auralization, particularly as the number of channels is increased [J. H. Rindel, F. Otondo, and C. L. Christensen, Proceedings of the International Symposium on Room Acoustics: Design and Science 2004, Paper V01 (2004)]. Further studies evaluating the quality of auralizations using one-channel, four-channel, and 13-channel anechoic recordings have been pursued. The effect of changing the room’s material properties was studied in relation to turning the source around 180 deg and on the range of acoustic parameters from the four- and 13 beams. As the room becomes increasingly diffuse, the importance of the modeled directivity decreases when considering reverberation time. However, for the three other parameters evaluated (sound-pressure level, clarity index, and lateral fraction), the changing diffusivity of the room does not diminish the importance of the directivity. The study therefore shows the importance of considering source directivity when using computer modeling. [Work supported by the National Science Foundation.]
Geographic Information Systems (GIS) analysis of high-resolution multibeam bathymetry and remotely operated vehicle data to model rockfish habitat preference
Authors: Summers-Morris Erica , Iampietro Pat , Kvitek Rikk
Published: October 2013

Management of declining rockfish stocks requires effective tools capable of providing accurate stock assessments of near-shore, high-relief habitat. Multibeam bathymetry, when analyzed with GIS landscape analysis tools, can create models which can identify preferred habitat based on species-specific parameters. For this study, high-resolution multibeam data of the Del Monte shale beds in Monterey Bay, California were analyzed in GIS for slope, rugosity, and relative topographic position to assess rockfish (Sebastes spp.) habitat preference. Video transects collected by a remotely operated vehicle (ROV) provided habitat ground-truth and fish distribution data. A series of habitat suitability models was created in GIS by combining different suitability factors from multibeam-derived grids: slope, rugosity, topographic position index (TPI), and depth. Distance to preferred categories for each parameter were determined for eight rockfish species. Of these, distance to peak features identified by TPI50 proved the most effective means of modeling fish distribution, successfully predicting an average of 80% of the eight rockfish species. Using fish distribution information, stock estimates were calculated for the study area. By combining GIS landscape analysis tools with multibeam bathymetry and ROV video data, we have created a predictive tool that can locate areas of most suitable habitat given rockfish-specific parameters.
How useful is bathymetric information in the classification of high frequency sonar surveys?
Authors: Atallah Louis , Probert Smith Penny
Published: October 2013

In several sonar studies, bathymetric information; is used for the correction of amplitude data and the calculation of backscattering strength, which is plotted versus grazing angle and used for seabed classification. Bathymetric data is also used as an easily viewed backdrop to visualize backscattered sonar data in surveys. This work proposes an automatic method that combines amplitude features (describing backscattering strength and sonar texture) with bathymetric features (indicating seafloor variability) for sonar classification. Features are selected per window (of user defined size) and areas around grab samples in a survey are used for training. The importance of bathymetric features is investigated in this study, and highlighted by feature selection algorithms as well as by scatter plots exploring the training areas. Classification rates are significantly improved when both amplitude and bathymetry features are used. The final results show the classified windows plotted versus their exact position in the survey. The method described in this work is applied to a sidescan bathymetric sonar dataset taken in Hopvagen Bay Norway. The methods are also applicable to other sonars which provide bathymetric information; a multibeam sonar is such an example.
Use of guided ultrasonic waves for characterization of cancellous and cortical bone
Authors: Sarvazyan Armen , Tatarinov Alexej
Published: October 2013

The possibility of accessing mechanical, structural, and geometrical parameters of both the cancellous and cortical bone components by different modes of ultrasonic guided waves has been demonstrated in several laboratories in Europe and the USA. Making measurements of acoustic wave propagation parameters in a wide frequency band, e.g., from 100 kHz to several MHz, enables assessment of bone layers at different depths from the bone surface. At lower frequencies, the acoustic wave velocity is found to be sensitive to changes of the cortical thickness in middleshaft areas. In epiphyseal zones, the measured low-frequency (100-kHz) wave, velocity reflects contributions of both the spongy and compact bone components and can be sensitive to changes of the trabecular structure. At higher frequencies in the MHz range, the main acoustic mode manifested in the received signal is related to the longitudinal wave, which characterizes mainly the elastic properties of the compact bone closer to the periosteum. Measurements of the ultrasonic pulse propagation parameters in a broad frequency band using surface transmission scanning mode enables the possibility to obtain the profile of acoustic properties of long bones. [Work supported by NIH and NASA.]
Correction for soft tissue in cortical bone assessment by ultrasound
Authors: Bossy E. , Talmant M. , Laugier P. , Roux C. , Kolta S. , Haguenauer D.
Published: October 2013

One of the key points in ultrasound measurements on cortical bone is the correction for soft tissue. We designed a new probe based on bi-directional axial transmission which automatically compensates velocity measurements for the soft tissue effect without preliminary evaluation of soft tissue properties. The probe consists in a linear arrangement of transducers with two sources placed on both sides of a unique group of receivers. The velocity of waves propagating parallel to the bone axis is deduced from a combination of the time delays derived from waves propagating in opposite directions at successive receivers separated by a known distance. This technique efficiently corrects for the major source of error on velocity encountered in clinical measurements which is caused by the variation of soft tissue thickness along the probe. The bi-directional technique was validated on test samples for which the residual precision error on velocity measurements was reduced to 0.2%. In vivo measurements yielded a value of 0.5% for the interoperator reproducibility. The clinical range of variation of the velocity measured by bi-directional technique is evaluated using clinical measurements on more than 200 subjects. Bi-directional transmission is a promising technique to minimize the variability of in vivo velocity measurements.
Ultrasound critical angle-reflectometry: Measuring ultrasound velocities in the clinic and in the laboratory
Authors: Antich Peter P. , Lewis Matthew A. , Richer Edmond , Smith Billy J. , Pak Charles Y. C.
Published: October 2013

Ultrasound critical angle-reflectometry is a modality developed and tested for measuring US velocity in the laboratory or the clinic. The applicator developed for use in the clinic consists of a transmitter concentric to a receiver, immersed in water and capable of analyzing multiple reflections from soft and mineralized tissues over angles from −45° to 45°. If a critical angle θc is detected in the spectrum, the velocity in bone is simply V=c/sinθc. The analysis can be repeated at different orientations; considering only p-wave velocities, as bone has transverse symmetry, there is a unique relationship between velocity and coefficients of stiffness: ρV2(φ)=C11cos4(φ)+C33sin4(φ)+ 2cos2(φ)sin2(φ)(C13+2C44). It can be shown that C11 and C33 give two orthogonal moduli of elasticity. Experiments show that the modulus of elasticity so derived is equal to that measured by mechanical testing. In addition to these angles we can measure the arrival time of the reflected signal and identify the depth from which the signal originates; for cortical layers of sufficiently small thickness it is possible to identify cancellous bone critical angles. Examples are provided which show that these quantities vary in response to metabolic and physical stimuli.
A new system for clincial ultrasound assessment of bone
Authors: Kaufman Jonathan J. , Luo Gangming , Englander Miriam , Siffert Robert S.
Published: October 2013

A new ultrasound device for noninvasive assessment of bone known as the QRT 2000 for Quantitative Real-Time—that is entirely self-contained, portable, and handheld is described. The QRT 2000 is powered by 4 AA rechargeable batteries and permits near real-time evaluation of a novel set of ultrasound parameters and their on-line display to the user. A clinical study has just been completed with the QRT 2000 in which 60 female subjects ranging in age from 25 to 88 were ultrasonically interrogated at their heels. The same heel was measured also using DEXA (PIXI, GE Medical Systems) and the bone mineral content (BMC) was compared with one ultrasound parameter which has been found to be extremely sensitive to bone mass. The parameter, known as the net time delay (NTD), and BMC had an associated R-squared value of 0.73, about a 13% improvement over presently marketed devices. This, coupled with the lower cost and portability of the system, makes the QRT 2000 ideally suited for use by primary care physicians in this country and abroad, and including for use in the developing world. Further improvements are being pursued through array methods (to improve reproducibility and correlations with BMD) and by incorporating other parameters particularly sensitive to architectural structure. [This research was supported by SBIR Grant No. 2R44AR045150 from the National Institute of Arthritis and Musculoskeletal and Skin Diseases of the NIH.]
Acoustic-to-seismic transfer function attribute for discrimination of false alarms and landmine detection
Authors: Fokina Margarita S. , Sabatier James M.
Published: October 2013

Acoustic detection of landmines based on the analysis of both spatial and frequency dependencies of the acoustic-to-seismic transfer function (A/S TF) utilizes the difference between mine impedance and the impedance of the surrounding ground. However, some deeply buried mines and some types of mines are hard to detect due to the natural variability of the ground. This work addresses the problem of false alarms and clutter (high values of the A/S TF in some frequency bands) that mimic the physics of a buried landmine. A time-scale, linear method (wavelet analysis) was used for improving the probability of landmines detection. Wavelet analysis of the calculated and measured signals permit one to find stable characteristics typical of the undisturbed ground, the disturbed ground, and the ground with a mine. The wavelet analysis showed that these characteristics may be used for the discrimination of landmines from false alarms. These characteristics also may be used as the additional criterion to find mines which are hard to locate by traditional methods. The advantages of the suggested technique are illustrated using the experimental data. Possibilities for buried landmine classification are discussed. [Work supported by ONR Grant N00014-02-1-0878.]