bluuebunny/crossref_metadata_2025 huggingface dataset:
Auditory-guided reaching movements in the peripersonal frontal space
Authors: Dramas Florian , Katz Brian F. , Jouffrais Christophe
Published: May 2008

Previous studies on auditory localization processes have shown that humans can localize sound sources accurately, including distance in certain situations. Few studies have examined auditory localization by binaural mechanisms in the peripersonal space. Numerous studies have examined auditory localization through verbal report or various pointing movements. This study examines the precision of hand "reaching" movement towards an auditory object. An experimental platform (semicircle, radius 1m) was constructed with 35 small loudspeakers placed under an acoustically transparent grid. Blindfolded subjects were seated within the platform at table height. Test protocol consisted of a brief audio stimulus presented via a single loudspeaker followed by the subject placing their index finger (preferred hand) at the location of the sound object. Optical finger tracking was used during the course of the experiment. Two test variables were investigated: different audio stimuli, Gaussian noise bursts varying the number and the duration of each burst; room acoustic conditions, with and without acoustical damping for reflection suppression. Preliminary results show precision of localization does not grow indefinitely with the number of burst repetitions but reaches a limit. Azimuth precision remains accurate, even with short burst conditions, contrary to the distance perception which increases with the stimuli duration.
In-situ observation of the perceptive process linked to dashboard tapping sounds
Authors: Montignies Francois , Nosulenko Valery , Parizet Etienne
Published: May 2008

It is well-known that in show-rooms some people might tap on the dashboard of vehicles. The aim of this study was to determine the importance of this phenomenon and to identify which properties of the vehicle are perceived through the sound thus produced. An ethomethodological observation was conducted to collect data about the action/perception process of a subject exploring a static vehicle. The work was based on the methodology developed by Nosulenko and Saymolenko to evaluate perceived quality using free verbalisations in a comparison task. 52 naive subjects were placed in ecologically valid conditions. Their task consisted in freely exploring two vehicles and selecting their preferred one. From a qualitative analysis of audiovisual recordings, a data base was built. It linked verbalisations, operations and perceived objects, and allowed the quantification of indicators related to activity and perception. The analysis of operations validated that the tapping operation was not anecdotal. Moreover, dashboard was one of the main perceived objects linked to to the auditive dimension. Finally, a significative effect of the tapping operation on the evaluation of dashboard material quality was observed, suggesting an implicite influence of sound on this perceived property.
Perception of Sound Source Distance and Loudness in a Coherent Field of a Reverberant Field
Authors: Hara Yoshifumi , Takahashi Yoshinori , Nomura Hiroaki , Tohyama Mikio , Miyoshi Kazunori
Published: May 2008

Perception of reverberant sound field changes with a sound source distance (SSD). This article describes SSD perception in a coherent region close to the sound source in the reverberation field. We performed listening tests for SSD perception and loudness of speech and carried out transfer functions analysis using a reverberant room. We confirm that both SSD perception and loudness are correlated to the standard deviation of the magnitude frequency response of the transfer function in the coherent region. That is SSD erception and loudness increase as SSD becomes long in the coherent region. However loudness decreases in an incoherent region. Consequently, we surmise SSD perception in the coherent region might be due to increase in loudness.
Directional loudness measurements for a multichannel system
Authors: Cabrera Densil , Miranda Luis , Dash Ian
Published: May 2008

Loudness matching listening tests were conducted to quantify the difference in loudness level from a constant signal played from various horizontal directions. The multichannel system used for this tests was a 5-channel system, set up according to the ITU Recommendation BS.116-1 Methods for the subjective assessment of small impairments in audio systems including multichannel sound systems and the test signals were octave bands of noise with centre frequencies from 63 Hz to 8000 Hz. These tests were conducted as part of ongoing research for the ITU Recommendation BS.1770 Algorithms to measure audio programme loudness and true-peak level. The aim of this experiment is to contribute to the design of a loudness meter by providing channel weightings, and results indicate that listeners are more sensitive to the surround channels than the other channels in the mid and high frequency range.
Investigating the potential of human echolocation in virtual sonic trigonometry
Authors: Neff Flaithri E. , Pitt Ian
Published: May 2008

Describing a mathematical problem often involves visual diagrams. For blind students this accentuates the challenges they face. Projects such as LAMBDA have used linear speech and Braille to convey algebraic equations. However, spatial features, for example in trigonometry, are difficult to map to a linear-based system. Traditional tactile methods (e.g. German film) convey simple shapes but need Braille support and speech-tactile interfaces (e.g. NOMAD) require unconventional equipment. Cognitive issues regarding tactile interpretation of 3D shapes also persist. Blind students interact regularly with speech technology and audio games. This exposure means that the auditory system is potentially becoming accustomed to sonic interpretation of computer-based information. Some of our research has looked at expanding the sonic environment to include spatial information aimed at trigonometry. The next stage is to provide interactive user control. Our system is based on a user interface model in order to consider the cognitive issues involved. We use Microsoft's XNA/XACT environment to create our auditory scene. In this paper we discuss how to implement sonic-based user interaction while further simplifying our auditory scene. In order to achieve this, we examine the potential of human echolocation to orient within the virtual walls and corners of a triangle.
Strategic listener movement in a model of auditory distance perception
Authors: Lu Yan-Chen , Cooke Martin
Published: May 2008

A mobile listener has the potential to exploit dynamic auditory cues to judge sound source distance. One such cue is motion parallax, which employs a sequence of azimuth estimates from interaural time differences to triangulate sound source location. However, distortions due to reverberation and competing sources complicate matters, so it is of interest to know what active strategies listeners might adopt to arrive at robust location estimates. One hypothesis is that not all listener motion trajectories are equally-beneficial for distance estimation. Trajectories designed via certain optimisation criteria might lead to faster and more robust estimates in a wider range of environments. Eight listener motion strategies were tested, from naive approaches such as random walks and head-rotation only to more sophisticated techniques based on sequential Monte Carlo methods. In the latter case, strategies included movement towards the expected source location, or in the most informative direction, or movement reducing overall uncertainty. Evaluation in a simulated acoustic environment with single sources under both anechoic and reverberant conditions demonstrated that moving towards the most likely source location led to the most accurate estimation of distance and subsequent tracking of a moving source. Significant problems remain in estimating distance in multi-source conditions.
Application of the fast multipole method for solving very large acoustic radiation problems
Authors: Hallez Raphael , De Langhe Koen , Tournour Michel , Abboud Toufic
Published: May 2008

Boundary element method is well known and extensively used to solve acoustic radiation problems. It is especially appropriated for exterior radiation since the fluid domain does not need to be meshed, as opposed to the finite element method. However, the mathematical formulation leads to a dense matrix system of equations. Therefore, the size of the model increases drastically as the frequency of analysis increases and huge computer resources are required to solve complex models in the mid-frequency range. The fast multipole method can be used to extend the boundary element model and solve such problems. For a model with N nodes, this technique brings the number of operations down to O(N*LogN) instead of O(N**3) for conventional boundary elements. This new methodology has been applied here to study the acoustic radiation of a complete car in the mid-frequency range. The accuracy of the results as well as the computation time demonstrate the great potential of this new method to solve very large acoustic radiation problems.
FE-Model Reduction for FE-BE Coupling with Large Fluid-Structure Interfaces
Authors: Junge Michael , Becker Jens , Brunner Dominik , Gaul Lothar
Published: May 2008

For the finite element method model, reduction techniques exist to represent the dynamic behavior of component substructures. Depending on the type of reduction method, the reduction basis contains constraint or attachment modes, which are computed for all structural degrees of freedom on an interface. The interface can either be defined by adjacent substructures or by coupling interfaces to other physical domains, as it is the case for FE-BE coupled systems. A large interface thus leads to an increased size of the reduced order model and limits standard model reduction techniques to applications with small interfaces. In this work, interface reduction methods are investigated. Here, the size of the reduced order model is decreased by reducing the number of retained interface modes, while marginally increasing the reduction error. A direct reduction method based on strain--energy considerations is presented. Additionally, an iterative reduction scheme is proposed which only adds a basis vector to the reduction basis, if the spanned subspace is sufficiently enlarged. The applicability of the proposed methods is shown for an example structure.
Modeling of the acoustic eigenproblem with sound absorption using boundary element method
Authors: Lavie Antoine , Leblanc Alexandre , Haddi Abdelkader
Published: May 2008

This paper deals with determination of resonant frequencies for absorbant 3D acoustic cavities. The behaviour of the sound absorbing boundary can be described with a Robin condition as proposed by Rajakumar et al. [Int. J. Numer. Methods Eng., 36, 3957-3072 (1993)]. This approach is inaccurate, especially for low frequencies because the absorption coefficient is assumed to be constant. We observed the acoustic admittance for foam and fibrous type materials varies linearly for low frequencies. The introduction of a new absorption coefficient allows to take into account this behavior in order to improve the accuracy in the determination of the first modes (typically less than 500 Hz in car interior). This formulation has been implemented in a boundary element program we have developed. The results are compared with those given by the finite element program ANSYS. Computations are carried out for rectangular parallelepiped and Sedan car interior.
Active noise control in turbofan aircrafts: theory and experiments
Authors: Monaco Ernesto , Lecce Leonardo , Natale Ciro , Pirozzi Salvatore , May Chris
Published: May 2008

This paper presents the activities developed by the authors within the research project M.E.S.E.M.A. funded by the European Commission. A noise and vibration control system using magnetostrictive actuators has been designed and experimentally tested on a large scale (fuselage mock-up) test article, for controlling noise and vibrations between 150 - 500 Hz. The environmental noise and vibration excitation was representative of a small/medium turbofan aircraft. Firstly a numerical model of the test article has been developed in MSC/NASTRAN coupling the structural part with the interior acoustic volume. Furthermore the experimental characterisation of the test-article has been carried on. The model, updated by the mean of the experimental results, was employed to derive the required control actuators performances in order to achieve the best control predicted using a well consolidated "feed-forward" approach. Genetic Algorithms have been employed in order to optimise the positioning of the actuators. Dedicated magnetostrictive actuators have been designed together with light power amplifiers meeting the specifications; on each actuator an optoelecronic sensor, based on Bragg grating, has been integrated to optimize the actuator performance. A two-level ANVC system has been designed and tested on a full scale fuselage mock-up. The paper present an overview of the activities developed as well as of the achieved results.
The stability of nonequilibrium supersonic boundary layer
Authors: Zavershinsky Igor
Published: May 2008

The present work looks at the influence of molecular vibrational energy nonequilibrium on the instability of boundary layer. The boundary layer loses its stability at supercritical Reinolds numbers. At small Mach numbers M < 2 can be unstable only Tollmien-Schlichting waves, which phase velocity in relation of mean flow is subsonic. The recent studies were shown that in the acoustically active gas the critical Reynolds number for subsonic disturbances is decreased in comparison with equilibrium media [1,2]. At large Mach numbers M > 2 in addition to Tollmien-Schlichting waves we must take into account both falling and reflecting acoustic waves (Mach waves). As a result the interaction between vortical structure and acoustic waves leads to shift of critical Reinolds number in comparison to subsonic case. Here the dependence of critical Reynolds number on thin flat plane from degree of nonequilibrium for spatial supersonic disturbances is founded. It was shown that acoustical activity of media has a large destabilizing influence. The increment of this instability is raised with growth of the degree of non-equilibrium. 1. Bertolotti F.P. J. Fluid Mech., 1998, V. 372. P. 93. 2. Knestyapin V.N., Kogan E.Ya., Zavershinsky I.P. High Temperatures. 2007. V.45. N2. P.1.
Coupled wavenumbers of structural acoustic waveguides: A unified asymptotic approach
Authors: Sarkar Abhijit , Sonti Venkata R.
Published: May 2008

In the literature, the coupled wavenumbers in flexible-walled acoustic waveguides have been found mainly using numerical methods for a fixed set of parameters. These solutions, although useful, do not continuously track the coupled wavenumbers as the fluid-loading parameter is varied from small to large values. Such a continuous tracking is possible by applying the asymptotic methods to the coupled dispersion relation. Analytical formulae for the coupled wavenumbers can also be found. In this work, we present a consistent, unified and physically insightful view of structural acoustic coupling in the context of a planar structural-acoustic waveguide (with two different BCs), the axisymmetric and beam modes of a fluid-filled circular cylindrical shell and finally a fluid-filled elliptic cylindrical shell. In all the five cases, we use a single fluid-structure-coupling asymptotic parameter (ε). The regular perturbation method is used to solve the coupled dispersion relation for small and large values of ε. The circular and the elliptic cylinders necessitate the use of additional asymptotic parameters. A general trend in all systems is that a given wavenumber branch transits from a rigid-walled solution to a pressure-release solution with increasing ε. Also, the wavenumber curves veer where the earlier uncoupled wavenumbers intersected.
Boundary element model to study sound transmission provided by a single panel in the presence of an elastic interlayer
Authors: Pereira Andreia , Tadeu António
Published: May 2008

In this paper the Boundary Element Method is applied to develop a numerical model which may be used to study the airborne and impact sound insulation provided by a single panel of infinite extent bounded by two fluid media, with an elastic interlayer (joint) inserted into the partition. The elastic interlayer is placed in the panel, perpendicular to the its surfaces and fully occupying the panel thickness. When the interlayer assumes the properties of a resilient material, it is able to reduce the wave propagation through the elastic medium of the partition. The model is excited by a harmonic line load that acts either in the fluid medium or in the elastic medium in the direction perpendicular to the panel's surface. The model is developed following a direct frequency domain formulation which assumes full coupling between the fluid media and the elastic media. Analytical Green's functions for an elastic single layer bounded by fluid media are used to avoid having to discretize the horizontal surfaces of the partition. Numerical simulations are displayed in order to illustrate the applicability of the proposed model to the analysis of airborne and impact sound insulation when an elastic interlayer is inserted into a single partition.
Numerical analysis of airborne and impact sound insulation between non-contiguous acoustic spaces using the Boundary Element Method
Authors: Pereira Andreia , Tadeu António , Santos Paulo
Published: May 2008

In this paper a Boundary Element Method (BEM) is used to predict the acoustic behaviour provided by four two-dimensional acoustic closed spaces separated by slabs and walls, surrounded by an elastic infinite medium. The walls and slabs are modelled as single partitions. The model is excited by cylindrical loads in the form of an airborne sound source placed in the acoustic space or an impact sound source acting on the slab, perpendicular to its surface. The formulation is developed following a direct BEM approach which assumes full coupling between the fluid medium and the elastic medium. The model requires the discretization of all interfaces and allows the analysis in the low and medium frequency range. A numerical analysis is performed to study airborne and impact sound insulation between acoustic non-contiguous spaces, where the sound pressure level which is established in the receiving room is due to flanking transmission. The influence of the structure's stiffness on the sound insulation is discussed for varying thicknesses of slabs and walls. The acoustic behaviour of the structure is described by sound insulation curves and average vibration velocity level curves of the walls and slabs and the results are discussed.
A transmission loss definition based on the root mean squared intensity
Authors: Wijnant Ysbrand H.
Published: May 2008

Numerical simulation enables the calculation of the sound power transmitted through any structure for any arbitrary source but it can not be used to determine transmission loss, which is based on the transmitted power divided by the incident power. One can calculate the active power (= incident minus reflected power), but one generally can not determine the incident and reflected power themselves. In fact, apart from 1 dimensional analysis, transmission loss is only defined for diffuse sound fields and it only quantifies the acoustical performance of the structure for this field and not for the actual, in-situ, source. While the incident power can not be determined, the active and root mean squared power can. The latter quantity is introduced and is a measure for the total energy flow per period, i.e. the net energy flow and the energy flowing back and forth. A transmission loss definition based on the ratio between the active power and the root mean squared power is shown to closely resemble the transmission loss in the 1 dimensional case. Results for a 2 dimensional case show that the ratio is a quantity which does characterize the transmission of the structure as it is excited by the source.
Articulatory comparison of spoken and sung vowels based on MRI
Authors: Badin Pierre , Henrich Nathalie , Lamalle Laurent
Published: May 2008

Understanding the differences of articulatory strategies between spoken and sung vowels is of interest to both speech and singing research. We have thus used MRI to record midsagittal images from three subjects producing sustained vowels with various characteristics. The subjects were a professional lyric soprano, a semi-professional soprano, and a semi professional bass. They were instructed to produce combinations of (1) the ten French or the five Italian oral vowels, (2) speaking, amateur singing, or professional singing modes, (3) chest or falsetto registers, (4) pitch levels varying from B2 (120 Hz) to F5 (700 Hz). Any combination that the subject would not feel comfortable with was excluded from the corpus. The midsagittal contours of the vocal organs (jaw, lips, tongue, velum, pharyngeal wall, hyoid bone, etc.) were manually traced on each image, and a number of articulatory measurements (jaw or hyoid bone height, lip aperture, tongue position, etc.) were automatically derived. Our contribution analyses the influence of the various production conditions on these articulatory characteristics, such as the jaw aperture increase related to pitch increase, or the lower position of the larynx for singing in comparison to speech. Some acoustics considerations will be discussed as well.
Resonance characteristics of the hypopharyngeal cavities
Authors: Honda Kiyoshi , Kitamura Tatsuya , Takemoto Hironori , Mokhtari Parham , Adachi Seiji
Published: May 2008

The hypopharyngeal cavities are the narrow, complex parts of the lower vocal tract that include the supraglottal laryngeal cavity and bilateral cavities of the piriform fossa. These small regions exhibit rather strong acoustic influence on vowel spectra in the higher frequencies and contribute to determining voice quality and speaker characteristics. The laryngeal cavity functions nearly as a Helmholtz resonator to generate an extra formant in the vicinity of 3 kHz, and the piriform fossa forms a pair of side-branches of the vocal tract to cause spectral zeros in the vicinity of 4-5 kHz. Vocal-tract models without employing these acoustic effects can hardly simulate natural-sounding voices of a particular speaker. Therefore, realistic acoustic models of vowel production must include the three functional components: glottal source sounds, hypopharyngeal-cavity coupling, and resonance of the vocal-tract proper. This presentation demonstrates the results from acoustic experiments on solid vocal-tract models and computer simulations of the cavities' effects based on our MRI-based visualization of the vocal tract. A possible control for singing voice qualities will be discussed based on the three-component model.
Observation of voice registers
Authors: Sakakibara Ken-Ichi , Imagawa Hiroshi , Kimura Miwako , Tokuda Isao , Nito Takaharu , Tayama Niro
Published: May 2008

In singing, voice register is one of the most salient aspects of voice quality, and it has therefore generated a lot of debates, acoustically, physiologically, and pedagogically. In singing, the voice registers can be physiologically classified into four categories: vocal fry, modal, falsetto, and whistle. In this study, vocal fold vibratory patterns appeared in each register were observed using high-speed images and simulated using the two-mass model. In vocal fry, three different vibratory patterns (aperiodic, subharmonic, and periodic with small open quotient) were observed. In addition, the simulation showed that transitions between the three different vibratory patterns are easy. In whistle, closure of the posterior part of glottis and rapid vibration of the anterior part were observed.
Cross-language study of age perception by elderly listeners
Authors: Nagao Kyoko , Riley Amanda K.
Published: May 2008

Recent studies show that perception of speaker's age is influenced by a listener's familiarity with the speaker's language. However, these results were based on young adult listeners. The current study examines whether language familiarity influences the perception of speaker's age in elderly listeners. The vowel stimuli was prepared from the sustained vowel /i/ collected from 30 native speakers of American English and 30 native speaker of Japanese. The sentence stimuli was taken from the reading of the North Wind and the Sun by these 60 speakers (in their native language). Fifteen elderly native speakers of English (mean age 73.5 years, range from 67 to 84 years) listened to both stimuli types and estimated the age of speakers. Correlation between perceived age and chronological age was moderate for the sentence stimuli, but weak for the vowel stimuli. Correlation between perceived age and chronological age was stronger when the listeners judged sentence stimuli in their native language than when they judged sentence stimuli in the foreign language (r=0.74 versus r=0.63). The vowel stimuli did not show the effect of speaker language. The results suggest that linguistic information has a critical role in age perception, regardless of listener's age.
Influences of perceived racial identity on human talker identification
Authors: Perrachione Tyler K. , Chiao Joan Y. , Wong Patrick C.
Published: May 2008

Talker identification, the process by which human listeners recognize individuals by their voice, is one of the most poorly understood abilities of the human auditory system. Current psychological models of talker identification rely on strict analogies to face perception and the visual system, despite differences in the objects of perception in these two modalities. Here we investigate the existence of an own-race bias in voice perception - a phenomenon which has been pivotal in the study of face perception. Our results demonstrate an own-race bias in talker identification: listeners of different ethnic backgrounds show an advantage for identifying individual voices of the same race as themselves. However, unlike in vision, the own-race bias in talker identification manifests based specifically on the perceived, but not actual, race of a talker. The influence of perceived race suggests physical (voice structural) cues do not give rise to this effect. Instead, the own-race bias in talker identification is a result of listeners' asymmetric exposure to talkers' socially-acquired manners of expression (i.e. the dynamic features of voice and speech). Such manners of expression may be stereotypically associated with a particular ethnic group, although not actually exhibited by all members of that group. [Work supported by NIH]
Signal densities and criterion variance in speech and nonspeech perception
Authors: Lopez-Bascuas Luis E.
Published: May 2008

The actual shape of signal densities has become an important issue when studying speech perception within the framework of Signal Detection Theory (SDT). Using an SDT model that allowed unequal criterion variances, López-Bascuas [Proc. Eurosp. 3, 2281-2283 (1995)] found that speech signals did not accommodate to the standard Gaussian assumption. However, Schouten and van Hessen [J. Acoust. Soc. Am. 104, 2980-2990 (1998)] measured response distributions directly and, assuming an interval scale, concluded that the Gaussian assumption held for both continua. Nevertheless, Pastore and Macmillan [J. Acoust. Soc. Am. 111, 2432 (2002)] applied ROC analysis to Schouten and van Hessen's data and their curves supported the Gaussian assumption for the nonspeech signals only. Later, López-Bascuas et al. [J. Acoust. Soc. Am. 115, 2465 (2004)] showed that non-linear z-transformed ROCs are not sufficient evidence for postulating non-gaussian signal densities. In this paper we try to figure out whether unequal criterion variances could underlie non-linear z-transformed ROCs by fitting a restricted Thurstonian SDT-like model to a nonspeech continuum composed by white noise and a square wave. The results indicate that unequal criterion variances is the possible cause of the deviant ROCs for nonspeech.
Perception of reduced speech: Approximated stops
Authors: Warner Natasha , Benjamin Tucker V. , Fountain Amy
Published: May 2008

Natural, spontaneous speech often shows extreme reductions of many speech segments, to the point of apparent deletion. Where the flap allophone of /t/ and /d/ is expected in American English, one frequently sees an approximant-like or even vocalic pattern, rather than a clear flap. Still, such tokens are usually perceived as containing a /t/ or /d/ (e.g. 'needle' even with a very reduced /d/ is usually not perceived as 'kneel'). The current work identifies acoustic characteristics of reduced 'flaps' and presents phonetic identification data for continua that manipulate these characteristics. Presence vs. absence of a dip in intensity, duration of that dip, and degree of that dip in decibels are manipulated. Degree of intensity dip has the strongest effect, with a minimal dip in intensity more likely to be perceived as 'kneel' and a strong dip in intensity more likely to be perceived as 'needle.' The results indicate that all three of these characteristics do affect listeners' percept of a consonant, but not sufficiently to completely account for the percept. Listeners are sensitive to the acoustic characteristics of consonant reduction, but they are also very skilled at evaluating variability along the acoustic dimensions that realize reduction.
Integrated magnetic resonance imaging methods for speech science and technology
Authors: Masaki Shinobu , Nota Yukiko , Takano Sayoko , Takemoto Hironori , Kitamura Tatsuya , Honda Kiyoshi
Published: May 2008

This presentation introduces our integration of magnetic resonance imaging (MRI) techniques at ATR Brain Activity Imaging Center (Kyoto, Japan) toward research into speech science and technology. The first breakthrough in our application of MRI to speech research was the motion imaging of the speech organs in articulation using a cardiac cine-MRI method. It enables us to acquire information in the time-space domain to reconstruct successive image frames using utterance repetitions synchronized with MRI scans. This cine-technique was further improved for high-quality imaging and expanded into three-dimensional (3D) visualization of articulatory movements. Using this technique, we could successfully obtain temporal changes of vocal-tract area function during a Japanese five-vowel sequence. This effort also contributed to developing other techniques to overcome the limitations of MRI, such as the post-hoc inclusion of teeth images in 3D volumes or the phonation-synchronized scan for crystal-sharp static imaging. Further, a custom high-sensitivity coil was developed to visualize the fine structures of the lip muscles and laryngeal airway. The potentials of new MRI approaches such as ultra-high-resolution imaging with a higher-field scanner or real-time motion imaging during a single utterance will be discussed toward future contributions to speech science and technology.
Linguistic versus non-linguistic processing of speech prosody in dichotic listening
Authors: Kanamura Ritsu , Imaizumi Satoshi
Published: May 2008

Linguistic and non-linguistic information processing of speech prosody are studied using two dichotic listening tasks, a Word task and a F0 task. During the Word task, subjects were required to identify either right- or left-ear stimulus from two-syllable homophonic words presented with different pitch accents. During the F0 task, subjects were required to identify either right- or left-ear stimulus from F0 partials extracted from the words used in the Word task. The correct percent of responses was high and RT was short for high familiarity words presented to the right ear rather than the others under the Word task, while no such differences were found under the F0 task. RT of the Word task was shorter than the F0 task. These results suggest that the processing of linguistic speech prosody under dichotic listening conditions is based on the interactive auditory and linguistic neural resources with right- ear or left-hemispheric dominance, and are faster than auditory F0 pattern identification. The tasks developed can be used to detect central auditory processing disorders.
Broader range of training voices improves performance of HMM model of phonemic identification
Authors: Parchment J
Published: May 2008

A model proposed by Lin (2005) learns phonetic categories from waveform input. Recorded speech from a set of male talkers is divided into training and test sets. The training set is separated into phonemes, subjected to cepstral analysis, and used as the input to a Hidden Markov Model, which clusters the phonemes into phonemic categories. After this unsupervised learning process, the model is then able to accurately identify speech segments in the test set, showing that relevant acoustic information is captured by the model. The current study explores the outcome when a model of this type is trained on a range of talkers differing in sex and vocal tract configuration. Preliminary results suggest that this approach can improve performance when testing is generalized to a wider range of new talkers. However, too wide a range of training voices reduces accurate categorization, while too narrow a range reduces generalizability. Continuing efforts seek to quantify the optimum range of training voices and to identify the variables that can predict the degree of improvement in performance on test voices. This work has implications for automatic speech recognition models as well as for issues of speaker normalization.
A Method of Co-registering Multiple Magnetic Resonance Imaged Vocal Tract Volumes for Fricatives
Authors: Proctor Michael I. , Shadle Christine , Iskarous Khalil
Published: May 2008

In a study of fricative production, Magnetic Resonance Imaging was used to acquire three-dimensional tract geometries of fricatives produced in four different vowel contexts. Short scan sequences were used to image multiple productions of each fricative in a single session. Although minimizing the number of tokens, this resulted in a coarser spatial resolution in some parts of the tract, which required a different approach to assembling vocal tract volumes. Sagittal, axial and oblique-coronal imaging orientations were chosen to best resolve the tract in the mid-sagittal plane, the pharynx, and around the fricative constriction. Each fricative token was acquired using a 37 second imaging sequence. Dental impressions were imaged separately. Three corresponding point clouds were created by sampling air-tissue boundaries in each image stack, and aligned using anatomical landmarks on the face and spinal column, creating a single, multiply-sampled volume. Area functions were estimated using the most suitable data source at each region of the tract. Vocal tract models were constructed for eight fricatives produced in four vowel contexts by four speakers of American English. The advantages of this method of tract modeling, and its automatic application to potentially variable MRI data sources will be discussed. [Funded by NIH-NIDCD-RO1-DC006705]
Acoustical analysis of Canadian and Parisian French word-final vowel productions in varying phonetic contexts
Authors: Law Franzo , Strange Winifred
Published: May 2008

Dialects can differ greatly in their phonetics and phonology, and can diverge to a great degree in vowel production. This study explores the acoustic nature of Canadian French (CF) vowels in word-final position, relative to those of Standard Parisian French (PF). CF and PF male participants were recorded producing minimal sets of words, differing in the final vowels /i y e "epsilon" a "o-bar" o u/, embedded in carrier phrases. Real-word minimal sets were constructed using words with final vowels preceded by labial, coronal, and back stops and fricatives. (Monosyllabic CV words were used whenever possible; VCV and CCV words were used when no CV word was available.) Nonsense disyllabic minimal sets were also recorded with vowels preceded by labial, coronal, and back stops in the following context: /gisCV/. Of particular interest was the stability of the /e - "epsilon"/ distinction in word-final position for Parisian French, which was maintained in preliminary results. Across-syllable boundary coarticulatory effects are also discussed. This is the first part of a larger study investigating second-language lexical and morphosyntactic CF vowel perception by English learners of French. [Work supported by NIH F31DC008075]
F0 contour estimation based on time-varying complex speech analysis
Authors: Funaki Keiichi
Published: May 2008

Robust F0 (Fundamental frequency) estimation plays an important role in speech processing such as speech coding and tonal speech recognition. We have already proposed robust F0 estimation algorithm based on time-varying complex AR (TV-CAR) speech analysis for analytic signal, in which the weighted autocorrelation function is calculated using the complex residual and then the F0 is searched as the peak sample for each frame [IEICE Trans. on Fundamentals, Vol.E91-A.No.3] [IEICE Trans. on Fundamentals, Vol.E90-A, No.8]. Although the algorithm can estimate more robust F0 estimation for IRS filtered speech corrupted by additive noise, the algorithm cannot perform better for non-IRS filtered speech or slightly contaminated IRS-filtered speech. In addition, the frame-based F0 estimation cannot extract the F0 trajectories in the time-domain. In order to cope with the drawbacks, this paper proposes quite simple F0 contour estimation algorithm based on the TV-CAR speech analysis, in which the F0 contour is estimated by peak-picking for the estimated time-varying spectrum that is the same manner as formant frequency estimation. The experimental results demonstrate that the proposed method leads to more accurate continuous F0 estimation than the conventional one for high-pitched speech due to the nature of analytic signal for non-IRS filtered high-pitched female speech.
Extraction of vocal tract area function from three-dimensional magnetic resonance images using digital waveguide mesh
Authors: Inoue Kenji , Takemoto Hironori , Kitamura Tatsuya , Masaki Shinobu , Nakashima Hirotake
Published: May 2008

A method is proposed in this paper to extract the vocal tract area function from the three-dimensional magnetic resonance images. The proposed method uses the digital waveguide mesh, an implementation of the finite-difference time-domain (FDTD) method, to simulate wave propagation in the vocal tract from the glottis to the lips. The dimensions of the vocal tract areas are then calculated along the traveling wavefront that emerges from the simulation. Formant analysis has been conducted for Japanese vowels to show the validity of the proposed method. The calculated formant frequencies of the area functions obtained by the proposed method and other existing methods have been compared to those measured from the acoustic utterance of the imaged person.
Perception of Japanese consonants by native speakers of American English
Authors: Nozawa Takeshi
Published: May 2008

Four native speakers of Japanese produced Japanese multi-syllable words and non-words, which include stops, fricatives, affricates, nasals and the liquid. Twelve native speakers of American English, who had never learned Japanese, heard their utterances and spelled out what they heard in English alphabet. What was of interest was whether native speakers of American English would perceive Japanese consonants in a way they are transcribed in English alphabet. The results revealed that Japanese stops were equated with generally the phonetically closest English stops, but voiceless stops were more likely to be equated with voiced stops of the same place of articulation than the other way around. Among voiced stops, /b/ and /d/ respectively were equated with /v/ and /l/. The word-initial /ts/, though words like "tsunami" have become part of English, was predominantly equated with /s/ rather than /ts/. The Japanese liquid, which is usually transcribed as /r/, was predominantly equated with /l/ rather than /r/. This agrees with results of previous research that demonstrate that English /r/ is more dissimilar from Japanese /r/ than English /l/ (See Aoyama et al. 2004).
Synchronous speech and speech rate
Authors: Kim Miran , Nam Hosung
Published: May 2008

Synchronously read speech has shown to reduce a high degree of speaker variability of reading exhibited by speakers in laboratory recording; e.g., pause placement and duration, and speech rate. However, quantitative analysis of speech rate has rarely been found in studies on synchronous speech. This study examines Mandarin Chinese (2 dialects from Taiwan and Shanghai), which is a syllable-time language and thus expected to exhibit a relatively stable speech rate, in both read-alone and read-together speech. Consistency and variability of speech rate are compared in both reading types across repetitions within a subject, across subjects, and across dialects. The results show that speech rate is more stable in read-together than in read-alone speech, and that speech rate in synchronous reading falls on a constant value of speech rate rather than on the average between the speakers' rates in pair. This global pattern is consistent across dialects, and stylized local variation of speech rate over prosodic units (Intonational phrase) is also observed unique to each dialect. We discuss how timing in synchronous speech cannot be accounted for only by dynamic entrainment of speakers with different speech rates and how there should also be rhythmic information shared by speakers of a language.
Comparison of the brain regions for consonant processing in Japanese and English subjects
Authors: Oya Yoshikazu , Irino Toshio , Hervais-Adelman Alexis G. , Ives David T. , Kawahara Hideki , Patterson Roy D.
Published: May 2008

A recent fMRI study on speech-sound processing by Uppenkamp et al. [Neuroimage, 31(3), 1284-1296 (2006)] revealed that regions of the left and right, superior temporal gyri (STG) and anterior, superior temporal sulci (STS) respond preferentially to speech-like stimuli. Hervais-Adelman et al. [BSA London (2007)] extended this research to investigate the processing of consonant-vowel (CV) and vowel-consonant (VC) syllables and determine the locus of consonant-processing in the brain of English speakers. This paper reports an experiment with the same stimuli but with Japanese subjects for whom VC syllables are a novelty. In both the English and Japanese subjects, there was enhanced activity in left STS for vowels over non-speech sounds, as in Uppenkamp et al. (2006). A significant difference was observed between the responses to CV and VC syllables in left STS and planum temporale (PT). There was almost no CV-VC difference in the English subjects. The activity regions for VC syllables were larger than for CV syllables in Japanese subjects, probably because the Japanese subjects would have heard the VCs as two syllable speech sounds. Research supported by JSPS Grant-in-Aid [B18300060] and the UK-MRC [G0500221, G9900369].
The relation between articulatory and aerodynamic properties of single /t/, /S/ and their combination in /tS/ and /St/
Authors: Fuchs Susanne , Koenig Laura L.
Published: May 2008

Intraoral pressure changes during speech production are a result of different factors, such as articulatory movements (place and manner of articulation), subglottal pressure, and laryngeal-oral coordination. This study attempts to provide a better understanding of the relation between aerodynamics and articulation in single voiceless consonants and their combinations. We gathered electropalatographic data simultaneously with intraoral pressure data for 9 native speakers of German. During voiceless aspirated stop production intraoral pressure equalizes with subglottal pressure since an oral closure is formed and the glottis is open. During voiceless fricative production intraoral pressure is lower than in stop production since the air can escape through the oral constriction. In /t, S, St/ the intraoral pressure changes are highly correlated with the articulatory behaviour. However, the affricate /tS/ shows an unusual relationship with aerodynamics and articulation. Although an oral closure is formed, pressure rises at a later point and reaches its peak during the fricative. We interpret these findings with respect to a special laryngeal - oral coordination in affricates as reported in Hoole et al. (2003) who found a relatively late glottal opening during the stop portion of the affricate.
FEM simulation of tongue deformation for /i/ with a four-cube model applied to tagged cine-MRI data
Authors: Takano Sayoko , Matsuzaki Hiroki , Motoki Kunitoshi
Published: May 2008

Roles of extrinsic and intrinsic tongue muscles in the production of vowel /i/ were examined using a finite element method (FEM) applied to the tagged cine-MRI data. It has been thought that tongue tissue deformation for /i/ is mainly due to the combined actions of the genioglossus muscle bundles advancing the tongue root to elevate the dorsum with a mid-line grooving. A recent study with the tagging-MRI revealed earlier, faster and greater tissue deformation at anterior top of the tongue than posterior part during /ei/ production. This result implies the contribution of the intrinsic tongue muscle (transverse anterior) with an independent hydrostat mechanism from that of the genioglossus muscle bundles. In this study, a simple four-cube model is built to examine the co-contraction effect of the genioglossus and transverse muscles using using the FEM. The simulation result with the anterior transverse muscle (Ta) showed good agreement with the pattern of the tongue deformation obtained from the tagged-MRI data, suggesting that transverse anterior also plays an important role for the realization of the tongue shape for the production of vowel /i/.
Classification of normal and pathological vocal fold vibrations using Phonvibrograms
Authors: Lohscheller Jörg , Voigt Daniel , Doellinger Michael
Published: May 2008

Clinical examination of voice disorders demands an endoscopical observation of vocal fold vibrations. High-speed endoscopy is the state-of-the-art technology for investigation of vocal fold vibrations. A novel visualization strategy is proposed which transforms the segmented contours of vocal fold edges into a set of two dimensional images, denoted Phonovibrograms (PVG). Within PVGs the individual type of vocal fold vibration becomes uniquely characterized by specific geometric patterns which can be seen as fingerprints of vocal fold vibration. The PVGs give an intuitive access on the type and degree of the laryngeal asymmetry which is essential to quantify the effects of functional and organic voice disorders. To determine the vibration characteristics within the computed PVG pattern recognition algorithms are applied. Thus, for each vocal fold the vibration type can be quantified and classified. The results of the PVG classification will be presented in 80 subjects (normal and pathological voices). It will be shown, that a classification of the vibration type can be performed very precisely even in disturbed vocal fold vibrations. The obtained PVG images can be documented and stored on a hard-disc using a lossless image data-format. The quantitative description of PVG patterns has the potential to realize a novel classification of vocal fold vibrations.