bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of directional microphones in an arbitrary sound field
Authors: Su Quang T. , Merlis Joshua H. , Antonelli Daniel , Miles Ronald N.
Published: May 2013

An acoustic characterization method for directional microphones is presented that does not require an anechoic chamber to provide a controlled plane wave sound field. Measurements of a directional microphone under test are performed in a nearly arbitrary sound field for several angles of sound incidence, and the corresponding sound pressure and pressure gradients in the vicinity of the test microphone are measured using an automated probe microphone scanning system. From these measurements, the total acoustic frequency response of the directional microphone can be decomposed into its sensitivities to sound pressure and pressure gradient using a least squares estimation technique. These component responses can then be combined to predict the directional response of the microphone to a plane wave sound field. This technique is demonstrated on a commercially available pressure gradient microphone, and also on a combination sound pressure-pressure gradient microphone. Comparisons with the plane wave responses measured in an anechoic environment show that the method gives accurate results down to 100 Hz.
Summer school for acoustics graduate students
Authors: Garrett Steven L. , Atchley Anthony A. , Hargrove Logan E. , Matula Thomas J. , Gladden Joseph R. , Bass Henry E.
Published: May 2013

In addition to subject mastery and the focused effort required to complete a thesis project, graduate students also need to develop a broad understanding of their field and cultivate a familiarity with the larger community of researchers and practitioners. The “summer school” format has been shown to enhance both subject-matter breadth and build community awareness in physical acoustics. Physical Acoustics Summer School (PASS) has been held in late-May, in even-numbered years, since 1992. The format for each day is usually two three-hour lectures followed by evening discussion groups to answer questions and explore extensions of the day’s lecture topics. One lecture session is typically dedicated to acoustics demonstrations. Attendance for the full week is required of all participants who also dine together three times each day. Venues are chosen to provide isolation that minimizes distraction and maximizes interactions among all participants. Typical enrollment has been 10 distinguished lecturers (including many Silver Medal winners in Physical Acoustics), 10 discussion leaders, and 30 graduate students. This format has been successfully extended to one other ASA Technical Committee: the marine bioacoustics community has held their summer school twice (SeaBASS). PASS has now been functioning long enough that former students have become lecturers.
Combining theory and experiment to teach acoustic concepts
Authors: Sommerfeldt Scott D.
Published: May 2013

A rigorous theoretical development is desirable to help students at both the undergraduate and graduate levels develop a deep understanding of acoustic phenomena. However, numerous students labor through the mathematics associated with the concepts without ever developing an understanding of how that translates over into the physical world. Many acoustic phenomena lend themselves to experimental demonstrations that can greatly aid students’ understanding of the physical concepts and help them connect the theoretical developments with what physically happens. These demonstrations also provide a means for introducing common issues associated with making acoustic measurements that can also be educational for students. As an example, this paper will focus on how we have developed concepts associated with vibrating strings in a class through both theoretical development and use of a relatively simple experimental apparatus. Students gain a much better understanding not only of modes associated with the string, but the relative accuracy of the underlying theory. In addition, basic signal analysis topics and measurement accuracy also surface in the process of making the measurements.
Teaching advanced undergraduate students principles of outdoor sound propagation using football game measurements
Authors: Gee Kent L. , Neilsen Tracianne B. , Wall Alan T. , Eyring Nicholas J.
Published: May 2013

As part of a sound system evaluation at Brigham Young University’s football stadium and to assist in planning for future system design, measurements were made before and during games by an upper-level undergraduate acoustics class. The measurement experience provided significant training opportunities for the students. Teams of students used sound level meters to make recordings at numerous locations both inside and outside the stadium. These measurements were then correlated with data from stationary microphones placed near the field. From the data, the predicted slow, A-weighted equivalent levels in and around the stadium were calculated relative to an assumed 90 dBA on the sideline. Straightforward outdoor sound propagation prediction methods involving geometric spreading, atmospheric absorption, barriers, etc. were successfully used to validate the measured data within 1-2 decibels at many locations, including a location in the foothills to the southeast of the stadium at a distance of approximately 3 km. The students appreciated the hands-on experiences gained by participation in the measurements and analysis.
Spectrogram puzzles: A tool for teaching acoustic phonetics
Authors: Bent Tessa , Garl Emily
Published: May 2013

One of the most useful tools for the acoustic analysis of speech is the spectrogram. A spectrogram is a visual representation of speech which includes time, frequency, and amplitude information. To conduct appropriate and accurate acoustic-phonetic analyses, students must learn to identify important features of vowels and consonants on spectrograms. To help students learn to identify these features, the spectrogram puzzle exercise was developed. In this exercise, spectrograms of sentences are printed using a large-format printer and cut into phoneme sections. Students then arrange the segments into the appropriate order based on a provided sentence. Depending on students’ level of knowledge and experience, task difficulty can be increased or decreased by: (1) providing phonetic transcription versus orthography, (2) including more or less easily identifiable consonants, (3) including citation-style speech versus conversational or disordered speech, and (4) having teams versus individual students complete the exercise. Through these modifications, this activity can be used with a wide range of students from beginning undergraduate to advanced graduate students. For all students, spectrogram puzzles provide a hands-on, interactive learning experience that can facilitate critical thinking, collaborative learning, and acquisition of knowledge about the representation of speech sounds on spectrograms.
Mechanical model of the human ear
Authors: Everbach E. C.
Published: May 2013

Diagrams showing cutaway views of the human ear are all very well for teaching the mechanics of hearing, but a tabletop model the students can manipulate is even better. The author presents a mechanical model based upon the water-tube cochlea previously developed by Robert Keolian, but including the outer- and middle-ear components. The model allows phenomena such as the acoustic reflex, critical bands, and masking of higher-frequency by lower-frequency tones.
Numerical study on the function of tone holes of a recorder like instrument from the viewpoint of the aerodynamic sound theory
Authors: Iwasaki Takuya , Kobayashi Taizo , Takahashi Kin’ya , Takami Toshiya , Nishida Akira , Aoyagi Mutsumi
Published: May 2013

We have investigated properties of tone holes of a small recorder like instrument by using compressible large-eddy simulation (LES), which reproduces fluid flow and acoustic field, simultaneously. When an acoustic flow of strong sound pressure passes through the junction between a tone hole and the main body of the bore, vortex shedding occurs, which induces unpleasant noises due to re-radiation of aerodynamics sound from the vortices. We have succeeded in reproducing this process and attempted to explain its mechanism from aerodynamic sound theory. We have also investigated how the position of the pad of a key above a tone hole, i.e., the distance between the pad and the top of the tone hole, affects the pitch of the excited wave in the pipe. Furthermore, we attempt to numerically reproduce the function of tone holes, namely change of notes. Opening and closing tone holes change the topology of bore geometry, which yields a moving boundary problem accompanied by topological change of numerical grids. We have developed a LES solver resolving the moving boundary problem and are planning to apply it to the problem of opening and closing tone holes.
Sound radiation of trained vocalizers
Authors: Boren Braxton B. , Roginska Agnieszka
Published: May 2013

Current research at NYU has focused on computational estimation of vocal loudness of George Whitefield, an Anglican preacher in the 18th century who reportedly spoke to crowds of 30,000 or more. After having established an overall level for his voice, we have begun investigating how his voice would have radiated spatially. Existing literature on the radiation of the spoken voice has focused extensively on the context of conversation in workspaces. These studies typically examine one soft, one normal, and one raised voice condition. Trained actors and orators, however, employ more methods of projection than are used in conversational speech and can achieve higher loudness as well. The radiation patterns from these types of communication have not been quantifiably studied yet. This paper investigates the radiation patterns of different methods of projection in trained vocalizers using relative intensity levels at 1 m from the front of the speaker. The results are compared to the existing data for conversational speech, and the implications to open-air oratory are discussed.
Vibrato rate variability in three professional singing styles: Opera, rock, and Brazilian country
Authors: Pecoraro Guilherme , Curcio Daniella , Behlau Mara
Published: May 2013

Vibrato is one of the most expressive aesthetic characteristics of singing voice. Indicative of good voice quality is typical of lyrical singing but it is also found in others styles of popular music. Acoustically, vibrato is defined as a long-term periodic modulation of the fundamental frequency. It occurs as a result of the laryngeal muscular system and is comprised of three main parameters: rate, extent, and amplitude variation. The main controversy refers to the physiological mechanism of vibrato production, specifically concerning its neurological conscious control, as well as the intra-subject variability of its acoustic parameters. In this study, we compare the characteristics related to vibrato rate (VR), assessing 423 emissions, from recorded samples, produced by 15 professional singers, publicly and artistically acclaimed in occidental culture, to represent three music styles: opera, rock and Brazilian country (sertanejo). We analyzed the samples through GRAM 5.01 and found that the VR was kept constant intra-subject, independently of the singing style. The mean values for the VR for opera and Brazilian country singers were higher than for rock singers. Effects of vocal training, kinship and aging on the vibrato rate, as well as technical skills to control it are objects of our future studies.
Phase-space visualization and real-time pitch tracking of vocal sounds
Authors: Terez Dmitry
Published: May 2013

Novel techniques for sound waveform visualization and real-time pitch tracking are presented. The use of techniques is demonstrated on vocal sounds such as singing and speech. The visualization of a sound waveform in two- or three-dimensional reconstructed phase space obtained via signal time-delay embedding provides a compelling alternative to traditional spectral envelope, for example, for looking at a timbral structure of a sound. This phase-space visualization is performed continuously on a sample-by-sample basis and results in a moving trajectory on computer display—a living and breathing picture of voice in real time. In addition, pitch of voiced sounds is detected and displayed in real time using original pitch tracking algorithm. The algorithm has minimal possible latency which allows obtaining reliable fundamental frequency estimates in less than two cycles of a quasi-periodic waveform, before human auditory system can register pitch sensation. The techniques are efficiently implemented in real-time software using ASIO drivers. The software can be used as a tool for teaching singing or vocal intonation patterns as it provides immediate visual feedback on minute changes in pitch, timbre, or loudness.
Automatic classification of road vehicles considering their pass-by acoustic signature
Authors: Valero Gonzalez Xavier , Alías Pujol Francesc
Published: May 2013

In order to assess the impact of environmental noise on a community, it is essential to accurately describe all the aspects and characteristics of the encountered noises. In this context, it would be of special interest to dispose of environmental noise monitoring stations capable of not only measuring the noise levels but also identifying the sources producing those levels. To offer such functionality, an algorithm to automatically recognize the noise sources is required. According to previous works, designing algorithms able to optimally distinguishing between road vehicle noise sources (i.e., light vehicles, heavy vehicles, and motorbikes) is a challenging issue. This paper proposes a recognition scheme that takes into account the perceived characteristics of road vehicles pass-by, which may be divided into different phases: approaching, passing and receding. By taking independent decisions for the pass-by phases, the proposed recognition scheme is able to improve the recognition of road traffic vehicles with respect to a traditional recognition scheme, specifically in 7% for light vehicles and in 4% for heavy vehicles.
An acoustic based method for jointly estimating speed and wheelbase length of two-axle road vehicles as they pass by
Authors: Marmaroli Patrick , Falourd Xavier , Hervé Lissek
Published: May 2013

This paper focuses on acoustic road traffic monitoring and looks, more specifically, into the problem of speed and wheelbase length estimation of two-axle vehicles as they pass by. It is known that both front and rear axle trajectories may be dissociated using cross-correlation based methods in conjunction with a well designed two-element microphone array placed on the roadside. This is mainly due to the broadband nature of the tyre/road noise which makes two peaks appear, one per axle, in the correlation measurement when the vehicle is in the broadside direction. This paper aims at analyzing such a “bimodal’’ observation in order to automatically extract the position, speed, and wheelbase length of passing-by vehicles. We propose to conduct this tracking problem using a particle filter that model the position-variant bimodal sound source nature of the vehicles. The theoretical developments presented in this paper are experimentally assessed through real in-situ measurements.
Aircraft noise technology review and medium and long term noise reduction goals
Authors: Tester Brian J. , Huff Dennis , Mongeau Luc
Published: May 2013

This presentation will summarize the recommendations of the second ICAO Committee on Aviation Environmental Protection noise technology independent expert panel. The technologies being developed for reducing aircraft community noise in the mid term (10 years) and the long term (20 years) were reviewed. The review consisted of detailed presentations on aircraft noise reduction by various industry and government representatives on component noise reduction programs, highlighting novel noise reduction concepts being pursued and the progress that has been demonstrated or projected so far.
Bandgap formation mechanisms in periodic materials and structures
Authors: Raghavan Lalitha , Phani Srikantha
Published: May 2013

Bandgaps are frequency intervals of no wave propagation for mechanical waves. Spatial periodicity provides one mechanism for the emergence of bandgaps in periodic composite materials such as lattice materials, phononic crystals, and acoustic metamaterials. Coupling a propagating wave in a periodic medium with a local resonator provides an alternate mechanism for band-gap emergence. This study examines these two band-gap formation mechanisms using a receptance coupling technique. The receptance coupling technique yields closed-form expressions for the location of bandgaps and their width. Numerical simulations of Blochwaves are presented for the Bragg and sub-Bragg bandgaps and compared with the bounding frequency predictions given by the receptance analysis of the unitcell dynamics. It is observed that the introduction of periodic local resonators narrows Bragg bandgaps above the local resonant bandgap. Introduction of two fold periodicity is shown to widen the Bragg bandgap, thus expanding the design space. The generality of the receptance technique presented here allows straightforward extension to higher dimensional systems with multiple degrees of freedom coupling. Implication of this study for nano-electro-mechanical systems (NEMS) based filters will be discussed.
Synthesis and frequency dependent ultrasonic characterization of NiO-EG nanofluids
Authors: Wan Meher , Verma Satyendra K. , Pandey Dharmendra K. , Yadav Raja R.
Published: May 2013

In the present paper, we have synthesized the NiO nanoparticles with chemical route. Further, the uniform suspensions of NiO nanoparticles in ethylene glycol of different concentrations have been prepared. Samples were characterized with Acoustical Particle Sizer (APS-100) for the frequency dependent ultrasonic attenuation in the respective samples; subsequently, the particle size determination and their distribution have been calculated with the help of ultrasonic attenuation. The structural parameters were also investigated with the microscopic techniques. There is good agreement between data produced by ultrasonic spectroscopy and the microscopic measurements.
Pneumatic infrasound source: Theory and experiment
Authors: Gorhum Justin , Muir Thomas , Slack Charles , Barlett Martin , Hawkins Timothy , Tinney Charles , Baars Woutjin
Published: May 2013

In prior work [J. Acoust. Soc. Am. 132(3), 2074 (2012)], we experimentally demonstrated the feasibility of releasing compressed air through a rotating ball valve to create infrasound. The present paper seeks to analyze and model those as well as new outdoor measurements, with a view toward establishing a viable theoretical model of the process. Functions involving propagation and the response to frequency, source pressure, and signal type (tone burst and transient) are examined, as is the potential utility of the method in calibration and test applications. [Work supported by ARL:UT Austin.]
Shear waves in inviscid compressible fluids
Authors: Godin Oleg A.
Published: May 2013

While elastic solids support compressional and shear waves, waves in ideal compressible fluids are usually thought of as compressional waves. Here, a class of acoustic-gravity waves is studied in which the dilatation is identically zero, and the pressure and density remain constant in each fluid particle. An exact analytic solution of linearized hydrodynamics equations is obtained that describes the shear waves in inhomogeneous, inviscid, compressible fluids with piece-wise continuous parameters in a uniform gravity field. The solution is valid under surprisingly general assumptions about the environment and reduces to some classical wave types in appropriate limiting cases. Free shear waves in bounded and unbounded domains as well as excitation of the shear waves by a point source are considered. Edge waves propagating along vertical and inclined rigid boundaries are found in rotating and non-rotating fluids. A possible role of the shear acoustic-gravity waves in a coupled ocean-atmosphere system is discussed.
Device for ultrasound imaging of standing trees
Authors: Arciniegas Andres , Brancheriau Loïc , Gallet Philippe , Lasaygues Philippe
Published: May 2013

The aim of ARB'UST project is to develop an ultrasonic device for parametric imaging of standing trees. The device is designed to perform both transmission and reflection measurements, used for quantitative tomographic imaging. It allows various automatic acquisitions since the angular position of sensors can be precisely adjusted. The electronics and associated configuration enable particularly the measurement of velocity and attenuation of the ultrasonic waves during their propagation within the medium. Two tomography experiments were conducted on a plane tree sample (before and after drilling a hole) and tomograms were calculated by the “Layer Stripping” algorithm. Our first results show that the artificial defect is detected.
Cell structure in waves diffracted by a wedge in three-dimensional space and its implications to the field theory
Authors: Ueda Mitsuhiro
Published: May 2013

In the previous meeting, we have reported that if the aperture angle of a wedge-like region in 2D space bounded by perfectly reflecting planes is expressed as πN/M where N and M are relatively prime integers, the region can be divided into N cells and diffracted waves in a cell can be reconstructed by the sum of those in N-1 cells remained. This property holds for any positions of observation and source points. In this paper, it is shown that the same cell structure exists in the 3D wedge-like region bounded by rigid planes. In this case, the time dependent explicit solution for diffracted waves is available in closed form involving elementary functions only. Consequently the existence of cell structure can be shown analytically whereas in the 2D case it was shown numerically since the stationary solution for diffracted waves is expressed in asymptotic form involving Bessel functions. It is not easy to notice the cell structure without the new physical principle of diffraction, that is, virtual discontinuity principle of diffraction that has been proposed by us. Some physical implications of the principle to the field theory are mentioned lastly.
Physical correlates of loudness transfer functions in binaural synthesis
Authors: Völk Florian , Fastl Hugo
Published: May 2013

The frequency dependent level correction necessary for a binaural synthesis system to elicit via headphones the reference scene loudness of narrow-band signals is referred to as loudness transfer function. An ideal binaural synthesis system provides frequency independent loudness transfer functions for every listener. The frequency dependence of the average of a binaural synthesis system’s individual loudness transfer functions has been shown to depend on the degree of individualization of the binaural synthesis system. In this contribution, perceptually acquired loudness transfer functions are compared from an auditory-adapted perspective to physical parameters of signals involved in the binaural synthesis process. The results provide quantitative relations between individual physical cues of the binaural synthesis output signals and the resulting loudness transfer functions.
Toward a listening in spatialized noise test using complex tones
Authors: Buchholz Jorg M. , Dillon Harvey , Cameron Sharon
Published: May 2013

The Listening in Spatialized Noise-Sentences (LiSN-S) test has been widely applied to diagnose spatial processing disorder in both normally hearing and hearing impaired listeners who are proficient in English. The overall goal of the present study is to develop a spatial listening test that assesses similar spatial auditory processes as the LiSN-S test but does not rely on speech input and thus is language independent. Therefore, a three-alternative forced choice (3AFC) stream segregation task was implemented using a series of continuously in- or decreasing tone-complexes as targets and random tone-complexes as distractors and foils. Similar to the LiSN-S test the signals were either spatially co-located or separated using non-individualized HRTFs and the difference in thresholds defined the spatial release from masking (SRM). In order to achieve similar large SRM effects (of up to 14 dB) as observed with the LiSN-S test in normal hearing listeners, temporal jitter had to be introduced. The effect of the amount of temporal jitter was investigated on the SRM as a function of tone-complex duration. The results revealed that a jitter of about 30ms in combination with a tone-complex duration of about 30ms is sufficient to elicit the desired SRM.
Physiological and behavioral studies of sound localization
Authors: Yin Tom C.
Published: May 2013

A critical job of the auditory system is to localize sounds, which depends upon spectral cues provided by the filtering of the pinna for vertical localization and interaural time (ITDs) and level disparities (ILDs) for horizontal localization. We found anatomical and physiological specializations in the circuits that encode these cues. Cells in the medial superior olive (MSO) function as high resolution coincidence detectors or cross-correlators and their inputs have enhanced temporal synchronization compared to auditory nerve fibers, and the speed of the calyx of Held synapse helps to convey the inhibitory input from the contralateral ear to the LSO synchronously with the excitatory input from the ipsilateral ear even though it has to travel farther with an additional synapse. We have also been studying the psychoacoustics of sound localization in the cat by training them to look at sounds. Cats demonstrate high accuracy and precision when localizing with their head unrestrained. Their mobile ears have a reflex in response to head movement that keeps the ears pointed toward the sound source despite head movements. Cats also experience the precedence effect and a physiological correlate of the effect can be seen in recordings from the inferior colliculus.
Analysis and optimization of constrained layer damping treatments using a semi-analytical finite element method
Authors: McDaniel James G. , Magliula Elizabeth A.
Published: May 2013

The present work investigates the physics of constrained layer damping treatments for plates and beams by a semi-analytical finite element method and presents applications of the method to the optimization of damping treatments. The method uses finite element discretizations in the thickness coordinate and propagating wave solutions in the remaining coordinates and therefore provides more generality and accuracy than existing analytical approximations. The resulting dispersion equation is solved for complex-valued wave numbers at each frequency of interest. By choosing sufficiently fine discretizations in the thickness coordinate, the method gives accurate estimates of wave numbers. The numerical implementation of the method is an efficient yet general tool for optimizing damping treatments with respect to material properties and dimensions. It explicitly allows for the possibility of analyzing structures with several layers where the material of each layer may be isotropic or orthotropic. Examples illustrate the numerical efficiency of the implementation and use this efficiency to provide optimizations of constrained layer damping treatments.
An overview of constrained-layer damping theory and application
Authors: Shafer Benjamin
Published: May 2013

Beginning in the early 1930s a variety of theoretical and experimental research has been published regarding the development and use of damping. What began as an experiment to reduce noise and vibration in metals and plastics has become a common treatment in an amalgam of applications. Constrained-layer damping (CLD) is a specific method of treatment commonly used in the aerospace and military industries. CLD may be described as a type of shear-related energy dissipation achieved by interconnecting two or more structural materials using a relatively thin viscoelastic layer. Among the advantages of using CLD as a damping treatment are the ability to obtain high loss factors with relatively thin configurations and that the stiffness of the composite system is not markedly increased. The analytic development of constrained-layer damping will be presented along with a brief discussion of the applications of CLD throughout history.
Nonlinear moduli estimation for rubber-like media with local inhomogeneities elastography
Authors: Krit Timofey , Andreev Valeriy , Kostikov Victor
Published: May 2013

Static shear deformations of a plane-parallel layer of rubber-like material created simultaneously with the uniaxial compression are considered. The layer is fixed between the rigid plates. Displacement of one plate relative to the other resulted in shear strain of the layer. This strain could reach 0.6 of the layer thickness. At such strain, effects due to the cubic nonlinearity arise. It is shown that measuring the dependence of the shear stress on the shear strain along one axis at different compression along the perpendicular axis one could determine nonlinear Landau parameters. The measurements were performed in two layers of polymeric material plastisol of 7 mm thickness with a rectangular base 8.9 × 8.9 cm, mounted between three aluminum plates. The upper plate was loaded with masses ranging from 0 to 25 kg and was fixed in each series of the stress-strain measurements. The values of the Landau coefficient A were measured in layers with different value of linear shear modulus. [Work supported by the Russian Foundation for Basic Research (Grant Nos. 12-02-00114 and 12-02-31418), and grant of the Government of the Russian Federation 11.G34.31.0066.]
The role of acoustic/perceptual salience in directional asymmetry in infant stop/fricative contrast perception
Authors: Nam Young-Ja , Polka Linda
Published: May 2013

The presence of stops in a language implicates the presence of fricatives but the reverse is unattested. Similarly, infants’ producing fricatives implies that they acquired stops. The privileged status of stops influences infants’ stop/fricative perception. For example, Altvater-Mackensen and Fikkert (2010) reported that Dutch-learning 14-month-olds noticed a fricative to stop change but not vice versa. These findings were interpreted in terms of phonological specifications while dismissing acoustic/perceptual factors. In this study, we assessed whether pre-linguistic infants show perceptual asymmetry. We tested English and French 4–5-month-olds using the look-while-listen procedure in which they were presented native nonsense syllables - /bas/ and /vas/. A mixed ANOVA showed a significant interaction between trial type and group (p = 0.027). Infants in /vas/-habituated group noticed the switch when the habituated fricative changed to a stop but infants in /bas/-habituated group did not notice the switch when the habituated stop changed to a fricative. This perceptual asymmetry in infants before babbling and word recognition stage indicates the potential role of acoustic/perceptual factors. We suggest that the above-mentioned privileged status of stops may reflect the possibility that stops are acoustically/perceptually more salient than fricatives. This salience difference is predicted to induce directional asymmetry in stop/fricative contrast perception.
Infants’ categorization of vowels with infant vocal properties
Authors: Polka Linda , Masapollo Matthew , Menard Lucie
Published: May 2013

Prior research shows that infants can recognize phonetic equivalence among vowels produced by adult men, women, and children. It is unknown whether this ability extends to infant vowel productions, which have unique properties due to the size and geometry of the infant vocal tract. The present study was undertaken to determine whether infants recognize infant vowel productions as phonetically equivalent to vowels produced by adults and children. Infants (4–6 months) were tested in a look-to-listen procedure using isolated vowels, /i/ and /a/, synthesized to simulate productions by men, women, children and a 6-month-old. Infants were first habituated to diverse productions of the same vowel produced by several adult male, female, and child speakers while they fixated on a checkerboard. Following habituation, infants were then presented infant productions of the same vowel (familiar) and the other vowel (novel) in four test trials. A novelty effect (novel > familiar) was observed showing that infants recognized the familiar infant vowel to be similar to the habituation vowel. The findings are discussed in terms of the emergence of perceptual constancy in the development of vowel perception raising issues about how and when such knowledge is acquired in relation to the infant’s own productions.
Inter-rater agreement on Mandarin tone categorization: Contributing factors and implications
Authors: Wong Puisan , Li Lingzhi , Yu Xin
Published: May 2013

Factors that may/may not influence inter-rater reliability in assessing the accuracy of monosyllabic Mandarin tones produced by children and adults were examined in three experiments. Experiment 1 investigated inter-judge reliability in two groups of Mandarin-speaking adults—one group from China and the other from Taiwan—on their categorization of filtered tones produced by adults and children. The results showed that the magnitude of inter-rater agreement was associated with the production accuracy of the speakers; the judges attained lower agreement in categorizing children’s tones than adults’ tones. All judges who indicated that Mandarin was their strongest language and that they had learned and used Mandarin since birth performed similarly in their tone categorization despite the fact that they came from and were residing in different countries. Similar results was found in experiment 2, in which one group of the judges in experiment 1 categorized tones produced by a new and larger group of adults and children, and in experiment 3, in which a different group of adults categorized another new set of tones produced by a different group of speakers. Implications of the findings in research design will be discussed. [Work supported by NIH-NIDCD (1 F31 DC008479-01A1) and NSF (OISE-0611641).]
Effects of phonological training on tone perception for English listeners
Authors: Liu Chang , Chandrasekaran Bharath
Published: May 2013

The goal of this study was to examine the extent to which phonological training improves categorical perception of Mandarin Chinese tones in native speakers of American English. Two sets of F0 continuums were generated from rising to level tones and from falling to level tones. Participants underwent identification and discrimination tasks before (pre-training) and after (post-training) phonological training. Pre-training tests showed that the tone identification shifted gradually from contoured tones (rising/falling) to level tones as a function of F0 frequency, while tone discrimination was near a chance rate across and within tone boundary. Phonological trainings were provided to listeners in two consecutive days with each session lasting for one hour. In phonological training, listeners were provided immediate feedback (correct/incorrect) after making response in Mandarin tone patterns. Results showed that tone identification function became significantly steeper with phonological training. Although no prominent peaks were found across tone boundaries in the discrimination function, the accuracy rate and response time of tone discrimination improved after training. Ongoing work is now testing the extent to which a longer training regiment can enhance categorical perception of tones.
Are two-year-olds sensitive to anticipatory coarticulation?
Authors: Minaudo Caterina , Johnson Elizabeth K.
Published: May 2013

Eyetracking studies have shown that adults are highly sensitive to subphonemic detail in speech [e.g., Shatzman and McQueen (2006)]. In some circumstances, adults use subphonemic coarticulatory information to anticipate which word will occur next in the speech stream [McDonough et al. (2009)]. In the current study, we ask whether two-year-old children use anticipatory coarticulation in a similar manner. Sixteen children were presented with pairs of images. In half of the trials, the names of the images presented on the screen had matching phonological onsets (e.g., doggy and ducky) that also matched in syllable length (e.g., monosyllabic or disyllabic). In the remaining trials, the names of the images had mismatching phonological onsets (e.g., cake and strawberry). In addition, a portion of each trial type was identity spliced (e.g., informative anticipatory coarticulation) and a portion was cross-spliced (e.g., misleading anticipatory coarticulation). We predicted that if two-year-olds are sensitive to anticipatory coarticulation, then they should be slowest to recognize named targets when the heard label was cross-spliced and the two objects on the screen had mismatching phonological onsets. However, all children looked to the named targets equally fast regardless of trial condition. Thus, no evidence of sensitivity to anticipatory coarticulation was observed.
An EMA-based articulatory feedback approach to facilitate L2 speech production learning
Authors: Suemitsu Atsuo , Ito Takayuki , Tiede Mark
Published: May 2013

When acquiring a second language (L2), learners have difficulty in achieving native-like production even if they receive instruction on how to position the speech articulators for correct production. A principal reason is that learners lack information on how to modify their articulation to produce correct L2 sounds. A visual feedback method using electromagnetic articulography (EMA) has been previously implemented for this application with some success [Levitt et al. (2010)]. However, because this approach provided tongue tip position only, it is unsuitable for vowels and many consonants. In this work, we have developed a more general EMA-based articulatory feedback system that provides real-time visual feedback of multiple head movement-corrected sensor positions, together with target articulatory positions specific to each learner. We have used this system to improve the production of the unfamiliar vowel /ae/ for Japanese learners of American English. We predicted an appropriate speaker-specific /ae/ position for each Japanese learner using a model trained on previously collected kinematic data from 49 native speakers of American English, based on vowel positions for the overlapping /iy/, /aa/, and /uw/ vowels found in both languages. Results comparing formants pre- and post-feedback training will be presented to show the efficacy of the approach.
Developmental aspects of American English diphthong trajectories in the formant space
Authors: Lee Sungbok , Potamianos Alexandros , Narayanan Shrikanth
Published: May 2013

Formant trajectories of five American English diphthongs embedded in the target words BAIT (/EY/), BITE (/AY/), POUT (/AW/), BOAT (/OU/), BOYS (/OY/) are investigated in the first two formant space as a function of age and gender. Age range considered is from 5 to 18 years. In this report, the focus is given on the differences in position between the start/end points of diphthongs and nine monophthongs. Averaged formant data across subjects in each age group are examined for this purpose. Two findings are worth mentioning. First, across all age groups, the start and end positions of diphthongs hardly match with the monophthongs that are typically used to transcribe the diphthongs across all age groups [cf. Holbrook and Fairbanks (1962)]. For instance, the start position of /EY/ is closer to /I/ than to /e/, and the end points of /EY, AY, OY/ are significantly different with respect to each other. Second, in addition to the larger size of vowel space, an overshoot trend toward the nominal end points of diphthongs is the most prominent developmental trend. That is, formant values of diphthongs produced by younger age children are closer to the nominal monophthongs used to transcribe the diphthongs.
What palatalized consonants can tell us about theories of loanword adaptation
Authors: Schwade Allan J.
Published: May 2013

Phonology- and perception-based theories of loanword adaptation clash over two different assumptions: what language background the adapter has and what cognitive component handles adaptation. Phonology-based theories argue that borrowers know both the source and borrowing language and that the phonology determines output forms; perception-based accounts argue that the borrower does not know the source language and that the phonetic decoder guides adaptation. Since there is no reason to believe that either population of borrowers cannot adapt words, a production experiment was carried out to test both populations/approaches. Four monolingual English and three bilingual English-Russian speakers were played currently unborrowed Russian words containing palatalized consonants and asked to repeat them aloud in an American English accent. Since palatalized velar and coronal stops are often articulated with some degree of affrication and monolinguals are unaware of this, it was predicted that they would sometimes adapt said consonants as affricates (tju > t∫u). However, since bilinguals are familiar with the co-articulatory affrication, they were not predicted to adapt palatalized stops as affricates (tju > tu). The results corroborated the hypothesis in that bilinguals never affricated while monolinguals affricated a tenth of palatalized stops—demonstrating that both theories make the correct predictions for their respective populations.
Six- and ten-month-old infants' perception of non-contrastive variation
Authors: Krieger Dena , Johnson Elizabeth K.
Published: May 2013

Recent evidence suggests that infants do not perceive all existing speech sounds from birth. For example, the velar and alveolar nasal place contrasts are so subtle that infants require experience to perceive it [e.g., Narayan et al. (2012)]. Here, we examine English-learning infants’ perception of another subtle contrast: pre-voicing on stop consonants. Six- and 10-month-olds’ ability to discriminate between voiced and voiceless stops (phonemically contrastive in English) as well as voiced and pre-voiced stops (allophonic in English, but contrastive in other languages such as Dutch) was tested using a variant of the stimulus alternation paradigm (SAPP). Six-month-olds (N = 34) distinguished between voiced and voiceless stops (p < 0.05), but not between voiced and pre-voiced stops. Ten-month-olds (N = 32) failed to discriminate either contrast. We conclude that (1) English pre-voicing may be a subtle contrast requiring experience to perceive, and (2) this version of the SAPP might not be an ideal methodology to examine discrimination abilities in 10-month-olds. Overall, our findings thus far fit well with the notion that some contrasts require experience to perceive, as well as with past studies reporting mixed results regarding English-learning infants’ ability to perceive pre-voicing contrasts [e.g., Aslin et al. (1981), Lasky et al. (1975)].
The effects of voicing and position in infants’ perception of coda consonants
Authors: Engel Kathleen , Archer Stephanie L. , Curtin Suzanne
Published: May 2013

Infants’ ability to discriminate contrasting acoustic information has been demonstrated with many of the speech contrasts found in the world’s languages. However, this ability seems to be positionally constrained. Contrasts in onsets are discriminated by young infants, but coda contrasts are not discriminated until around 16- to 20-months [Zamuner (2006)]. Here we examine whether the contrast and the position influence discrimination in younger infants. We tested 64 12-month-olds’ discrimination of voiceless (/p/, /k/), or voiced stops (/b/, /g/) in either word-final (VC; Exp. 1) or word-medial (VCCV; Exp. 2) position. Experiment 1 habituated infants to ap or ak (voiceless) or to ab or ag (voiced). At test, infants heard the same token presented during habituation (same) and a novel token (switch). Planned comparisons revealed that only infants in the voiced condition looked longer to the switch than the same trial (p < 0.05). In experiment 2, infants heard apta or akta (voiceless) or abta or agta (voiced), but no effects of trial type were found, suggesting that the perceptual advantage in word-final position does not exist in word-medially. Thus, in word-final coda position voiced stops are more acoustically salient than voiceless stops, providing infants with added information to aid in discrimination.
Listener judgments of age in a single-talker 48-year longitudinal sample
Authors: Ferguson Sarah H. , Hunter Eric J. , Mellum Catherine A. , Rogers Lydia R.
Published: May 2013

Numerous studies have demonstrated that listeners can make relatively accurate judgments of a talker’s age from hearing the talker’s voice. Materials in these previous studies have included sustained vowels (phonated and sometimes whispered), sentences, and passages of discourse. The number of talkers has ranged from 4 to 150, but in nearly all cases talkers were recorded only once. In the present study, the materials were recorded from a single talker who gave regular public speeches over a period of 48 years. Young adult listeners performed age judgments on samples extracted from 20 speeches chosen at 2–3 year intervals spanning the 48-year period, three samples per speech. Samples lasted 5 to 10 s and were chosen to minimize content that would identify the talker or link samples from the same speech to each other. In separate experiments, listeners listened to these 60 samples and after each one judged the talker’s age either by choosing from three categories (50–66, 67–83, or 94–100 years) or by making a direct age estimate. Accuracy of these estimates will be compared to previous studies and examined as a function of both the talker’s chronological age and acoustic measures performed for this talker in a separate experiment.
Examining the relationship between the interpretation of age and gender across languages
Authors: Plummer Andrew R. , Munson Benjamin , Ménard Lucie , Beckman Mary E.
Published: May 2013

Speech signals vary substantially in a number of their key properties, with the variability deriving from, among other things, talkers’ age and gender. Speech processing requires resolution of this variation, necessitating interpretation of age and gender information in the signal. In some signals, the age and gender are not clear from acoustic information alone. In these cases, there may be substantial individual variation in judgments of age and gender. This study examined the interplay between the interpretation of age and gender across language communities. Corner vowel stimuli ([i], [u], [a]) generated by an age-varying articulatory synthesizer set at seven different ages (6 months, 2, 4, 5, 10, 16, and 21 years) were presented to native speakers of Cantonese, English, and Japanese. Listeners assigned an age (in years) and a gender (along a visual analog scale ranging from “definitely male” to “definitely female,” or the equivalent in Japanese or Cantonese) to each stimulus. Analysis revealed a bifurcation in the interpretation of age and gender for the age 10 stimuli, which subjects rated as either a younger male or older female, suggesting a nonuniformity in the resolution of variability during speech processing. Preliminary analysis further suggests that this nonuniformity may be culture-specific.