bluuebunny/crossref_metadata_2025 huggingface dataset:
Rounding and palatalization convergence in Twi.
Authors: de Jong Kenneth J. , Obeng Samuel Gyasi
Published: October 2005

This paper reports an acoustic and articulatory study of labio-palatalization in Twi Akan (West African). Labio-palatalization is rare cross-linguistically, as would be predicted from theories of vowel dispersion, since palatalization and labialization have opposite effects on second formant frequency. Labio-palatalization in Twi, however, is the ongoing result of a convergence of contrastive consonant rounding and vowel-induced palatalization which have been functionally combined in certain segments. Preliminary palatographic data indicate that rounded coronal consonants have more posterior coronal constrictions. Present acoustic analyses show rounded consonants to be marked by a lowering of F3. Combining coronal retraction and rounding, thus has two effects. (1) It produces a stable region of low F3, as indicated by nomograms in Wood (1986). (2) It increases front cavity length, resulting in a lower and more compact spectrum of consonantal frication noise. Thus 1) examining the role of uncommon contrasts in a phonemic system can shed light on posited mechanisms for language change, and 2) rounding may serve different roles in different language systems, to lower both front and back-cavity resonances, or a more specific role of lowering front-cavity resonances which shape consonantal noise.
The acquisition of Taiwanese (Amoy) initial stops.
Authors: Pan Ho-hsien
Published: October 2005

Taiwanese (Amoy) is one of the few Chinese dialects with a three-way contrast. There are three Taiwanese syllable initial voiceless unaspirated stops, /p,t,k/, three voiceless aspirated stops, /ph,th,kh/, and two voiced stops, /b,g/. This paper reports on two studies of the acquisition of the voicing contrast in Taiwanese. The longitudinal study followed two girls from about 28 months to 33 months and to 40 months, respectively. The cross-sectional study compared VOTs in 54 children ranging from 30 months to 6 years. In the longitudinal study, the children had already begun to acquire the contrast between the two voiceless stop types in the beginning of recording, although there were still many tokens of voiceless aspirated stops produced with short lag VOTs. Later, the VOTs of the voiceless aspirated stops were hyperaspirated with VOTs exceeding the adult norm, and there were fewer tokens with short lag VOTs. Both children began to acquire the voiced stops around 33 months. The cross-sectional study confirm Kewley-Port and Preston’s (1974) claim and shows further that 6-year-olds’ production of voiced stops is not completely adult-like.
Perception of English /r,l,n,d/ by native speakers of Chinese.
Authors: Schmidt Anna Marie
Published: October 2005

Speakers of some southern dialects of Chinese do not make a distinction between /n/ and /l/ in Chinese. Previous pilot research indicated that they also have difficulty with this distinction both perceptually and productively in English. As a basis for an experiment in training this distinction, a closer exploration of these speakers’ perception of English was performed. This study examined these speakers’ perception of English /r,l,n,d/. Five native Chinese speakers heard English words from minimally different sets produced by three native English speakers and labeled the first consonant of each word. Native English speakers labeled the same sets with high accuracy. Results and implications for training will be presented.
Lexical stress perception by hearing-impaired listeners.
Authors: Barac-Cikoja Dragana , Revoile Sally
Published: October 2005

Identification of lexical stress in VCVs isolated from sentences was studied for moderately to profoundly hearing-impaired listeners. Two factors, sentential stress position and speech rate, were manipulated separately in the production of ‘‘You put VCV to bed.’’ When sentential stress was manipulated, each of: you, put, VCV, bed, was stressed. When speech rate (fast and slow) was manipulated, the VCVs were from sentences with stress on the VCV only. Twenty VCVs for each speech rate and ten VCVs for each sentential stress position were tested. Hearing-impaired (n=33) and normal-hearing listeners (n=8) identified whether the VC or the CV was stressed. In contrast to the normal-hearing listeners, lexical stress identification by the hearing-impaired listeners was significantly reduced for the fast speech rate. Both listener groups showed the same effect of sentential stress location: Performance was best when emphasis was on the VCV, and worst when either constituent adjacent to the VCV was emphasized. Results will be discussed with reference to the acoustic consequences of the production constraints and the accessibility of the prosodic cues to the hearing-impaired subjects as predicted by several audiological and psychoacoustic variables. [Work supported by NIH and the Gallaudet Research Institute.]
Comparison of Caseygrams for normal and pathological speech.
Authors: Vaidya P. G. , Behrman Alison , Winkel C. R. , Alforde Sally
Published: October 2005

In this paper, vowel sounds produced by healthy speakers and those produced by speakers suffering from certain pathologies are compared using differential trans-spectrograms, or the ‘‘Caseygrams.’’ These Caseygrams are generated as follows: First, the vowel sound samples are optimally reconstructed to reduce leakage errors. The data are then partitioned into many smaller samples. Each of these is transformed into the frequency domain. These FFTs are used to calculate two different types of trans-spectral coherences (TSCs). [Please see Vaidya and Anderson, J. Acoust. Soc. Am. 89, 2370–2378 (1991).] These two TSCs are specifically developed to measure the interaction of the main harmonics with the subharmonics. Positive results in this differential trans-spectrogram (Caseygram) indicate that chaos is present, either in a nascent state or fully developed state. It is expected that these Caseygrams would give an early warning of impending disorders and would also help monitor recovery from disorders such as damage to the speech center of the brain following a stroke.
Speech motor coordination in children with phonological disorders.
Authors: Fourakis Marios , Xu Ying , Edwards Jan
Published: October 2005

This study examined the question of whether children with phonological disorders have problems in speech motor coordination. Four children with phonological disorders, four typically developing children matched for age and gender, and four adults were asked to say multiple repetitions of ‘‘bad dog’’ at normal and fast rates of speech. The productions were digitized and formant tracks were obtained using LPC analysis. Standard deviations were calculated over the second-formant values frame by frame along the four 50-ms spans of the CV and VC transitions. The F2 tracks of the adults were much less variable than those of both groups of children. The F2 tracks of the phonologically disordered children were more variable than those of their typical age peers for three of the four transitions; however, the F2 tracks of the phonologically disordered children were less variable than their age peers for the initial ‘‘ba’’ transition, the only transition in which the tongue was not involved in both the consonant and the vowel articulation. This result suggests that children with phonological disorders may have difficulty in rapidly sequencing gestures that involve conflicting configurations for the same articulator.
Speakers’ production of word frequency according to semantic and pragmatic contexts and to a production versus perception representation.
Authors: Charles-Luce Jan , Dolena Kristin R. , Chappell Lorrie , Dressler Kelly M.
Published: October 2005

It has been shown that speakers adjust their articulation according to the amount of semantically biasing information in the whole utterance. Furthermore, subjects modify their speech production for the benefit of a listener. In the present investigation, speakers’ production of high- and low-frequency words was examined when produced in two semantic contexts (semantically biasing and semantically neutral) and in two pragmatic contexts (presence or absence of an overt listener). In addition, speakers were instructed to produce the target words in a production mode versus a perception mode of experience. For example, speakers were instructed to interpret the words according to how frequently they ‘‘say’’ the word or how frequently they ‘‘hear’’ the word. The results of acoustic measurements showed that subjects’ production of high- versus low-frequency words was affected by the semantic and pragmatic contexts. However, subjects modified their articulation differently depending on the mode of experience in which they interpreted the words’ frequency. These results will be discussed according to pragmatic compensation and semantic activation in speech production and, in particular, how speech production may be affected by the speakers’ representation of lexical items according to their production versus perception mode of experience. [Work supported by NIDCD.]
Gestural overlap analysis of lenis stop reduction in Korean.
Authors: Lee Sook-hyang
Published: October 2005

Korean lenis stops have been reported to become voiced intervocalically (Kagaya, 1974) and are often reduced to sonorants in casual speech with different degrees of reduction depending on the place of articulation (Lee, 1995). Velar lenis stops are more often reduced than the labials and coronals, which makes sense from the point of view of articulatory phonology (Browman and Goldstein, 1990). The oral gesture for a velar stop is on the same vocal tract tier (tongue body tier) as the neighboring vowels, so it should be more affected by overlap and blending with the vowel gestures than the closure gestures for other stops. This study investigates in what vowel environments lenis stop closure shows the most reduction. /VCV/ tokens in carrier sentences were recorded and acoustic analysis was done. The results showed that generally, reducing lenis stop closure is most in the environment of preceding and following low vowels, and least in the environment of high vowels, where the tongue body gestures of neighboring vowels are more compatible with the stop’s gesture. Labials, especially when they are in the high rounded vowel environment, showed a larger amount of reduction, which makes sense from the point of view of articulatory phonology, since one of the oral gestures for a labial stop is on the same vocal tract tier, lip tier, as the surrounding rounded vowels.
Criteria and examples of the use of visualization in underwater acoustics.
Authors: Zingarelli R. A. , Chin-Bing S. A.
Published: October 2005

Visualization in underwater acoustics is a relatively new field, with a peculiar set of promises and pitfalls. Advanced computer graphics can provide insight into physical processes, but only if the tools are simple and flexible enough to provide ‘on the fly’ visualization as the research is being done. Furthermore, ‘reality checks’ against standard benchmark solutions must be performed at every opportunity. Here, examples are presented of utilitarian visualization for time-domain sound propagation, how these are checked against reference solutions, as well as some interesting cases where these checks were not made. [Work supported by ONR.]
Animations of acoustical pulse (time-domain) signal propagation in a realistic waveguide to high frequencies.
Authors: Sidorovskaia Nataly A. , Werby Michael F.
Published: October 2005

Recent developments have made it possible to perform propagation calculations in realistic oceans to high frequencies. It is possible to deal with on the order of hundreds of modes rather quickly and by storing the frequency-domain field over some specified range over the water column and for a fine frequency mesh, it is possible by a new Fourier transform algorithm to reconstruct time-domain solutions in reasonable times. Time frames can be produced for various pulse forms and realistic animations can be created. Thus this enables concentration on the physics of pulse arrivals as well as distortion effects from submerged inclusions. The insight that arises from these calculations, whether they are still shots or actual animations, is very revealing and affords an additional perspective of the complete process that otherwise would not be revealed by less ambitious calculations. A variety of animations and still shots for several physical environments are presented and much of the theoretical results with the intuitive powers that only animations offer are described. [Work supported by Naval Research Laboratory and Office of Naval Research.]
Understanding acoustic propagation in shallow water via animations.
Authors: Schneider John B. , Flynn Patrick J. , Broschat Shira L.
Published: October 2005

Modeling the propagation of acoustic energy in shallow water is difficult due to the complexity of the environment. Roughness at the air–sea interface and bottom, inhomogeneities in the water column and sediment, and discrete scatterers affect the propagation. Although many modeling techniques are available to study this problem, arguably none is general enough to provide robust and accurate results over a large region when several complicating physical features are present. Instead, simplifying assumptions are often made, and the effect of such assumptions on the model’s validity is uncertain. Here, propagation in shallow water is studied via animations of the results obtained using the finite-difference time-domain method (a powerful, but computationally expensive, modeling technique with few inherent assumptions). Such animations provide insight into the relative importance of certain physical features that is not easily obtained from ‘‘still’’ data. Two different types of animations are discussed. One employs a ‘‘side-by-side’’ comparison in which time-domain propagation is shown in both the presence and absence of a certain physical feature. In the other, time is held constant and a physical feature is varied from frame to frame. Creation of animations using freely available software is also discussed. [Work supported by ONR.]
Higher-order modal reflection and transmission in acoustic waveguide step discontinuities.
Authors: Muehleisen Ralph T.
Published: October 2005

Analytic expressions for the transmission and reflection coefficients of higher-order modes at a step discontinuity in an acoustic waveguide are developed. The equations take on the familiar form of an impedance discontinuity when written in matrix form. Numerical results show that there is significant modal coupling which indicates that the coupling cannot be ignored in the design of duct systems.
Higher-order modal reflection and transmission in acoustic waveguide junctions.
Authors: Muehleisen Ralph T.
Published: October 2005

Analytic expressions for the transmission and reflection coefficients of higher-order modes in acoustic waveguides are developed and explored. When written in matrix form the equations take on the standard form of an impedance discontinutity. Numerical results for a right angle bend and a T junction show that there is significant coupling between modes, especially to the plane-wave mode. The results indicate that modal coupling cannot be ignored in the design of active and passive attenuators that need to work at higher frequencies.
Quantitative analysis of corvid (class aves) vocalizations as a possible taxonomic tool.
Authors: Coldren Mary K.
Published: October 2005

Vocalizations of scrub jays (Aphelocoma coerulescens texana and A.c. woodhouseii) and gray-breasted jays (A. ultramarina couchii) were recorded at eight sites in Texas. All three taxa were considered allopatric. While many call types were not consistent in structure and tended to intergrade, two structurally distinct call types were identified as shared by all taxa at all sites. Differences in acoustic structure of both call types was greatest between species. Acoustic structure between subspecies was less distinct, with unique acoustic structures occasionally being shared with the nearest population of another subspecies. Morphometric analysis revealed a similar pattern, with the most differentiation at the specific level, followed by subspecific and, lastly, by populational differentiation. Of particular interest was a small, isolated population of A. coerulescens found in the Texas panhandle. Although breeding populations may have existed for only two or three decades, morphometric analysis of both call types showed marked vocal differentiation from other Texas scrub jays. Analysis of one call type suggested separation from the other populations of scrub jays at the subspecific level, while the other call type suggested separation at the specific level.
Removal of multipath effects from marine mammal vocalizations.
Authors: Thode Aaron M. , D’Spain Gerald L. , Hodgkiss William S. , Kuperman W. A.
Published: October 2005

Long-duration (≳1 s) marine mammal vocalizations (i.e., blue whale calls) generate echos and other multipath effects [McDonald et al., J. Acoust. Soc. Am. 98, 712–721 (1995)], obscuring the original structure of the call, which may contain valuable anatomical information about the animal. Several deconvolution techniques are evaluated for their effectiveness in removing multipath effects from both a hypothetical and actual marine mammal call. The evaluation is first performed on a model of a whale call in an isovelocity waveguide with noise, where the source signal is known and can be compared with the output of the deconvolution schemes. The methods are then applied to two blue whale calls recorded during an experiment (SWellEx-3) in July, 1994 in 200-m water. The depth and range of the animal at those two times had previously been determined by matched field processing. As the position of the animal is known, the resulting multipath propagation can be computed and the accuracy of the techniques in identifying those multipaths determined.
Time-frequency analysis of potentially disturbing sounds in the environments of captive and wild fish.
Authors: Clark Joseph A. , Young Jane A. , Bart Amrit N. , Zohar Yonathan
Published: October 2005

Time-frequency analysis provides a detailed means to characterize features of sounds which might affect animals. Graphic displays of the analyzed sound fields often reveal qualitative patterns and quantitative measures that can be used as a basis for comparing different sound fields. The displays can be animated and presented in conjunction with audio recordings of the sounds and with video recordings of the environments in which the sounds were produced in order to assist in identifying sources and effects of the sounds. Modular signal processing software, integrated with a high level programming language and operated on graphics workstations enable the researcher to select specific types of sounds which are found to occur in typical environments of selected animals. The system can also be used to synthesize calibrated sets of similar sounds to be used as inputs for controlled experiments investigating the effects of the sounds on animals. In this paper, a typical workstation-based system for performing time-frequency analysis of digitally recorded sound will be described. Operation of the system will be illustrated with results from analyses of sounds collected during a recent survey of the acoustic environments of captive and wild fish and with specialty sounds synthesized for current investigations of effects of noise on fish.
An ‘‘acoustic-signature’’ model of vowel evolution.
Authors: Owren Michael J.
Published: October 2005

Recent work in bioacoustics has emphasized the importance of cues to individual- and kinship-identity in ‘‘signature’’ calls produced by many animal species, including nonhuman primates. Applying the source-filter approach to sound production in monkeys and apes, it is proposed that low-pitched, tonal calls may be significantly better-suited to providing these indexical cues than are noisy or high-pitched vocalizations. As the supralaryngeal vocal tract is relatively inflexible in many primates, harmonically rich calls produced by different individuals should exhibit stable, subtly distinctive spectral characteristics due to intraspecies variation in vocal tract size, shape, and tissue properties. Based on field studies of calls from baboons and rhesus monkeys, it is suggested that protohominids routinely uttered vowel-like sounds long before the development of speech. Laboratory tests of pure-tone and formant frequency discrimination in monkeys and humans further indicates that detailed formant-related characteristics in these sounds were likely both functionally important and perceptually salient. Due to changes in facial morphology (probably reflecting dietary factors), shortening of the protohominid vocal tract created selection pressure for lower laryngeal position to maintain acoustic-signature cues. Laryngeal descent therefore set the stage for development of flexible vocal tract positioning, but was not itself an adaptation for speech.
Loss factors of pipelike structures containing beads
Authors: Maidanik G. , Dickey J.
Published: October 2005

It is found that when beads are inserted into the interior of a pipelike structure, the damping of this beaded structure may substantially exceed that of the unbeaded structure. The beads are modeled by a ‘‘beaded fluid’’ characterized by a low density, a low sound speed, and a high loss factor. Statistical energy analysis (SEA) is developed to account for the presence of the beaded fluid within the structure. It is shown that in certain frequency regimes and certain choices of the parameters that characterize the beaded fluid, relative to those that characterize the structure, the loss factor of the beaded structure can be designed to significantly exceed that of the unbeaded structure. The mechanism for the increase lies in that the stored energy in the beaded fluid may, in the ‘‘steady state,’’ be made to substantially exceed that in the structure. The bulk of the stored energy is then decimated by the high damping capability that the beaded fluid enjoys. A selected number of computer experiments are cited to illustrate the potential effectiveness of this damping mechanism and the manner by which the parameters that define the beads and the structure, control it.
Acoustic properties of permeable membranes
Authors: Takahashi D. , Sakagami K. , Morimoto M.
Published: October 2005

Membranes used for building materials have a certain degree of acoustic permeability, which has been disregarded in general membrane-vibration theory, and may cause serious effects especially on the acoustic properties. In this study, a theory for sound absorption of, and sound transmission through, a single permeable membrane is developed. Subsequently, sound absorption of structures composed of air layers, absorptive layers, and the facings of permeable membranes is investigated theoretically, and discussed in comparison with the experimental data measured by using the reverberation-room method. The results are in fairly good agreement; thus the present theory should give an effective tool for prediction of the acoustic properties of this type of membrane structure.
Autocorrelation phase at one period lag: A rigorous approach
Authors: Mauuary D.
Published: October 2005

The method used by Birdsall et al. [J. Acoust. Soc. Am. 96, 2353–2356 (1994)] is a particular application of the generalized cross-correlation function introduced by Knapp and Carter in 1976 and extended for differential phase and Doppler estimation by Wax in 1982. The rigorous derivation of the phase estimate at one period lag in ocean acoustic tomography is reformulated, using the equivalence with an array model.
Task dynamic and articulatory recovery of lip and velar approximations under model mismatch conditions
Authors: McGowan Richard S. , Lee Mindy
Published: October 2005

An algorithm for recovering task dynamics and speech articulator movements from speech acoustics was tested under various model mismatch conditions. There was evidence of articulatory compensation to recover tract-variable (constriction) trajectories in speech produced with a lip approximation under sufficiently constrained conditions. However, in more extensive studies of lip and velar approximations, the recovered tract-variable trajectories were also different from those of the data-producing utterance. This phenomenon can occur because the matching criterion in the analysis-by-synthesis procedure is an acoustic criterion and the correspondence between the tract-variable trajectories and the acoustic output is not exact. While there may be some tract-variable compensation to attain a good acoustic match, there is evidence of a correspondence between how well the tract-variable trajectories match and how well the formant frequencies match in particular instances.
Strong fluctuation theory for a mean acoustic field in a random fluid medium with statistically anisotropic perturbations
Authors: Zhuck Nickolay P.
Published: October 2005

The problem of linear propagation of a time-harmonic acoustic field in an infinite statistically homogeneous fluid is considered. The aim of this investigation is to calculate the effective constitutive parameters which determine the properties of a random fluid with respect to the mean field for the case of strong fluctuations of density and compressibility. This is achieved by using a bilocal approximation and a renormalization method. Special emphasis of the present paper is devoted to statistically anisotropic perturbations. It is shown, through analytic examples, that the statistical anisotropy of strong density fluctuations essentially modifies the random medium effective properties compared to the case of statistically isotropic perturbations, and has a significant effect on propagation characteristics of the mean acoustic field.
Observer weighting of concurrent binaural information
Authors: Stellmack Mark A. , Lutfi Robert A.
Published: October 2005

Two experiments examined how listeners weight binaural information of individual components in a multicomponent complex when they are instructed to use this information in various ways. On each experimental trial of the first experiment, a two-component complex consisting of a 553- and 753-Hz pure tone was presented to listeners over headphones. Each component had an interaural difference of time (IDT) that was randomly chosen from a single distribution. Listeners were to indicate the apparent position of the intracranial image relative to the midline on the basis of either the IDT of the 753-Hz component, the sum of the IDTs of the two components, or the difference between the two IDTs. Observer weights for the component IDTs were derived by computing the point-biserial correlations between the IDTs of the components and the listeners’ left–right judgments. Three of the four listeners were found to adjust their weighting of the binaural information appropriately for each listening task, while the fourth listener consistently gave almost no weight to the 553-Hz component regardless of the listening condition. In a second experiment, listeners were instructed to attend to the randomly selected IDT of one of three components (553, 753, or 953 Hz) and to indicate whether the intracranial image produced by that component was to the left or right of midline. Only one of six listeners gave greatest weight to the target component regardless of its frequency. The other five listeners gave significant weight to all three components in all listening conditions. In all cases, individual differences in percent correct performance could be attributed largely to individual differences in weights with little variation in internal noise.
The effect of level and relative frequency region on the recovery of overshoot
Authors: Overson Gary J. , Bacon Sid P. , Webb Teresa M.
Published: October 2005

Overshoot—in particular, threshold for a signal near masker onset—can be reduced by presenting a stimulus (precursor) just prior to masker onset. The recovery of overshoot can be examined by varying the delay between the offset of the precursor and the onset of the masker, where ‘‘recovery’’ denotes an increase in the threshold for a signal near masker onset. The present study examined the effects of stimulus level and relative frequency region on this recovery. In all experiments, the masker was a broadband of noise and the signal was a 4-kHz sinusoid. The first experiment examined the effects of masker level on overshoot in order to choose two levels (one ‘‘low’’ and one ‘‘high’’) that produced similar amounts of overshoot; these levels were used in the remaining experiments. In the second experiment, the precursor was identical to the masker, and recovery functions were measured for both low and high masker and precursor levels. There was no consistent difference in the recovery functions between the two levels. In the third experiment, the precursor was divided into two bands (one below and one above 4 kHz); one was presented continuously while the other was gated as in experiment 2. The recovery was more complete when the band above 4 kHz was gated, although the recovery was usually less than that observed in experiment 2 when (effectively) both bands were gated. The results suggest that frequency regions on both sides of the signal are important for the recovery of overshoot, but that the frequency region above the signal may be more important than the region below.
Middle-ear development VII: Umbo velocity in the neonatal rat
Authors: Doan Daryl E. , Igic Petar G. , Saunders James C.
Published: October 2005

Laser interferometry was used to measure umbo velocity in the developing rat. The tympanic membrane was stimulated with pure tones between 0.4 and 40.0 kHz, at intensity levels between 50 and 130 dB SPL. The corresponding umbo velocity response was measured. Umbo velocity responded linearly with respect to sound pressure throughout development. When the stimulus level was held constant at 100 dB SPL, all animals displayed a velocity response that increased with frequency until a peak response was reached at about 20.0 kHz. Above this frequency the response decreased in all age groups. Umbo velocity increased with age at all frequencies, and at 1.0, 2.0, 4.0, 8.0, 16.0, and 32.0 kHz the velocity reached 90% of its mature value by 68, 24, 24, 15, 19, and 50 days after birth, respectively. These age-related increases in tympanic membrane velocity coincided with improvements in compound action potential (CAP) thresholds (as measured by other investigators) at similar frequencies. Both umbo velocity and CAP thresholds showed substantial growth after 10 days of age. The role of middle-ear functional development with respect to overall auditory sensitivity is discussed.
Temporal integration of loudness as a function of level
Authors: Florentine Mary , Buus So/ren , Poulsen Torben
Published: October 2005

Temporal integration of loudness for 1-kHz tones and broadband noises was compared over a wide range of levels. Absolute thresholds and levels required to produce equal loudness were measured for 5-, 30-, and 200-ms stimuli using an adaptive, two-interval, two-alternative forced-choice procedure. Levels ranged from 5 to 80 dB SL for noises and from 5 to 90 dB SL for tones. Results for six listeners with normal hearing show that the amount of temporal integration, defined as the level difference between equally loud 5- and 200-ms stimuli, varies nonmonotonically with level. The average amount of temporal integration varies from about 10–12 dB near threshold, to a peak of 18–19 dB when the 5-ms tone is about 56 dB and the 5-ms noise is about 76 dB SPL; the amount of temporal integration decreases to 10 dB for tones and 13 dB for noises with levels around 100 dB SPL. The data for tones are in good agreement with the majority of existing data. The data for noises are within the range of the few previous data, but the effect of level differs from that obtained in previous studies. The present results indicate that the growth of loudness may, at least in part, be consistent with the nonlinear input/output function of the basilar membrane.
Listeners do hear sounds, not tongues
Authors: Fowler Carol A.
Published: October 2005

The paper first distinguishes the two perceptual theories, the motor theory and the theory of direct perception, that nearly agree in the claim that listeners to speech perceive vocal tract gestures. Next it justifies the claim of the direct realist theory that listeners perceive gestures and consider some experimental evidence in its favor. Finally it addresses evidence and arguments judged by Ohala to disconfirm the theory. The argument is made that most of the evidence put forward by Ohala is irrelevant to a distinction between theories that we perceive acoustic signals and theories that we perceive gestures. The arguments are inaccurate or highly selective in the data upon which they draw.
Cues for perception of synthetic and natural diphthongs in either noise or reverberation
Authors: Nábělek Anna K. , Ovchinnikov Alexandra , Czyzewski Zbigniew , Crowley Hilary J.
Published: October 2005

The relationship between relative intensity of transition segments and identification of diphthongs has been investigated. In the first experiment, synthesized /ɑ i/ stimuli were used. The stimuli differed in the amount of attenuation of the transition segment which ranged from 0 to 15 dB. It was expected that /ɑ/ responses would be obtained for stimuli with attenuated transitions. The stimuli were tested in quiet, noise, and reverberation with ten normal-hearing and seven hearing-impaired subjects. For the stimulus with the most attenuated transition, the normal-hearing subjects gave no /ɑ/ responses and the hearing-impaired subjects gave only 20% /ɑ/ responses in quiet. However, in noise, both groups of subjects gave 70% /ɑ/ responses and in reverberation, the normal-hearing subjects gave 95% and the hearing-impaired subjects gave 90% /ɑ/ responses. Generally, less transition attenuation was needed for the hearing-impaired than for the normal-hearing subjects to give /ɑ/ responses. These findings indicated that identification errors in noise and reverberation for naturally produced diphthongs might be related to the intensity of their transition segments. In the second experiment, naturally produced diphthongs /ɑ i, ɑu, ɔi/ from the Nábělek et al. [J. Acoust. Soc. Am. 92, 1228–1246 (1992)] study were spectrally analyzed. There were 30 different tokens for each diphthong. The results of the analyses indicated significant correlations between the number of identification errors for these diphthongs made by either normal-hearing or hearing-impaired subjects and the relative intensities of the F2 transition segment. In both noise and reverberation there were fewer errors for the diphthong tokens characterized by high intensity F2 transitions.
Possible word boundary constraints on multiple activation of form-based representations of spoken words.
Authors: Luce Paul A. , Newman Rochelle S. , Lyons Emily A.
Published: October 2005

Most current theories of spoken word perception (e.g., Cohort theory, TRACE, Shortlist, Neighborhood Activation Model) propose that multiple form-based representations of words are activated in memory during recognition. Few of these theories, however, specify the precise nature of multiple activation of words in fluent speech or the constraints on activation imposed by information within the speech signal. The degree to which word boundary information in two-word sequences may limit lexical hypotheses during recognition was examined. Using a cross-modal priming technique, spoken two-word utterances, such as NOTE-RAIL, were presented and the activation of possible lexical items spanning the word boundary (e.g., TRAIL) was investigated. The implications of these results for current theories of spoken word recognition will be discussed. [Work supported by NIDCD.]
The segmental representation of words as revealed by priming in a lexical decision and naming task.
Authors: Palmer Nancy J. , Sawusch James R.
Published: October 2005

In previous studies, a priming task was used to explore the nature of the segmental representation of words. The phonetic overlap between primes and targets was varied. When phonemes occurred in the same syllable position in prime and target, responses to the target were faster than when prime and target shared no common phonemes. In contrast, when prime and target shared phonemes but the phoneme positions were different, no facilitation of target responses was found. New studies have further examined the segmental representation of speech using a new set of stimuli with both naming and lexical decision tasks. While previous prime–target pairs have been either both nonwords or words, the new studies include word–nonword and nonword–word trials. Additionally, the vowels in CVC prime and target were varied to examine the influence of the vowel similarity on priming when prime and target have consonants in common (e.g., prime ‘‘cat,’’ target ‘‘kit’’). Results will be discussed in terms of their implications for the nature of the abstract, segmental representation that underlies word recognition and lexical access. [Work supported by NIDCD Grant No. R01 DC00219 to SUNY at Buffalo.]
Building lexical neighborhoods.
Authors: Vitevitch Michael S. , Luce Paul A.
Published: October 2005

The Neighborhood Activation Model (NAM) states that the speed and accuracy of spoken word recognition are a function of the number and nature of neighbors—or similar sounding words—activated in memory by stimulus input. In particular, the model states that spoken word recognition is a function of (1) target word frequency, (2) similarity neighborhood density, and (3) similarity neighborhood frequency. In a pretest–training –posttest design, these three factors were manipulated using nonword target words and nonword neighbors to test directly predictions of NAM. The results were only partially consistent with the model. As predicted, processing times to high-frequency targets increased as a function of neighborhood density. However, processing times for low-frequency targets actually decreased with increased neighborhood density. Furthermore, no significant effects of neighborhood frequency were obtained. The implications of these findings for NAM and other models of spoken word recognition are discussed.
The neighborhood characteristics of malapropisms.
Authors: Vitevitch Michael S.
Published: October 2005

This study examined the neighborhood characteristics (frequency, density, and neighborhood frequency) of 138 malapropisms (whole word errors). A qualitative analysis suggests that words that are more often involved in malapropisms have low neighborhood frequencies. Additionally, these words tend to be either high-frequency target words in dense neighborhoods, or low-frequency target words in sparse neighborhoods. Finally, malapropisms tended to occur such that the word that was substituted for the intended word was more frequent than the intended word. The implications of these findings for models of lexical representation and processing are discussed.
Perceiving the sex and identity of a sine-wave talker.
Authors: Fellowes Jennifer M. , Remez Robert E. , Rubin Philip E.
Published: October 2005

Listeners can readily perceive both the linguistic message and the identity of the talker from an utterance that has been replicated with a few time-varying sinusoids. One puzzling outcome of studies of the identification of sine-wave talkers is that erroneous identifications did not cluster by sex. Males were often mistaken for females, and vice versa. A series of new experiments used frequency transpositions of sinusoidal replicas of speech to determine the acoustic attributes responsible for the identification of a talker’s sex and a talker’s identity. The central spectral tendency of a sinusoidal sentence was found to affect the perception of the sex of the talker; a sine-wave pattern derived from the formant frequencies of an individual talker seemed male, female, or neither when transposed to match the male, female, or overall average formant frequencies in our talker set, respectively. However, performance on a test of individual recognition was very good under acoustic conditions that reduced sex determination to chance levels. This suggests that recognizing a sine-wave talker does not depend on prior identification of sex, and begins to explain why listeners are likely to confuse sine-wave talkers without regard for the talker’s sex. [Work supported by NIDCD.]
Talker variability effects on spoken word recall: Encoding or rehearsal?
Authors: Topcu Meral , Mullennix John W. , Bakalis Tina , Stauch Maria , Tracevski Tina
Published: October 2005

The effects of talker variability were examined for spoken word recall. In this study, a serial word recall paradigm was used, with talker variability manipulated using single- and multiple-talker lists and with presentation rate varied using fast and slow conditions. In addition, memory rehearsal processes were examined via a continuous distractor task. Under no-distractor conditions, the results showed that primacy recall performance was better for single-talker lists compared to multiple-talker lists. Under distractor conditions, when presentation rate was fast, this difference remained. However, when presentation rate was slow, there was little difference in recall for single-talker versus multiple-talker lists. These results will be discussed in terms of the roles of rehearsal and encoding processes in the transfer of voice information to episodic memory for spoken words. [Work supported by NIH Grant No. DCO1667-03.]
The effects of multiple-talker stimuli on immediate memory span.
Authors: Saldaña Helena M. , Svec William R.
Published: October 2005

Previous experiments revealed that changing the voice between study items on an auditory list of letters results in a decrease in memory span [H. M. Saldaña, J. Acoust. Soc. Am. (1995)]. This finding is contrary to Baddeley’s articulatory loop model which defines memory span in terms of time or duration of items. According to this model items are stored as memory traces that fade after approximately 2 s unless revived by an articulatory control process [A. D. Baddeley and G. J. Hitch, Psychol. Learn. Motiv. (1974)]. The number of items that can be reactivated within the decay time can be retained indefinitely. The present study replicates and extends the previous memory span findings by utilizing digits instead of letters and by using a stimulus matching methodology for estimating span length. A reconceptualization of the articulatory loop model is discussed which takes into account the encoding of stimulus variability. [Work supported by NIH.]
Enhancement of concurrent vowels: Postcursor effects and thresholds.
Authors: Paschall D. Dwayne
Published: October 2005

Speech communication often takes place in noisy environments, including situations where two or more voices compete for the attention of the listener. Experiments with simultaneous vowel pairs investigated aspects of a priming stimulus that draws attention to a target voice in a mixture of two voices. Previous studies have shown identification accuracy is higher in conditions where the vowel pair was preceded by a precursor with the same F0 and spectrum envelope as one of the vowels. These findings are consistent with an explanation based on auditory adaptation. This conclusion is reinforced by results from the present experiments which show that when the precursor is placed after the concurrent vowel pair (a postcursor), there is little benefit to identification accuracy. Thresholds for identifying a target vowel in the presence of a masker vowel when a precursor is present with the same intensity, F0, and spectrum envelope as the masker vowel suggests that the phenomenon of enhancement appears consistently only when the enhanced vowel and the precursor are at similar intensities. The present experiments suggest that enhancement is the result of perceptual grouping mechanisms that are supplemented by adaptation processes possibly operating at a level more central than the auditory nerve.
Vowel perception in consonant context.
Authors: Thorburn Rachel
Published: October 2005

Macmillan, Goldberg, and Braida [J. Acoust. Soc. Am. 84, 1262-1280 (1988)] show that when stimuli are presented along a continuum, instances of consonants that are near good exemplars are most memorable for labeling by a listener. However, for vowels (produced in isolation), instances which are near category boundaries are most memorable. Can these results be generalized to vowels produced in context? What is the effect of different consonant contexts on vowel perception? To answer these questions, this study tested high vowels along a front–back continuum produced in two CVC contexts (labial or alveolar). The results show that these vowels produced in context exhibit the patterns Macmillan et al. (1988) discovered for consonants, consistent with the idea that both vowels in context and consonants are perceived as linguistic entities, whereas isolated vowels are not. The results also show a difference in perception between the two consonant contexts. For vowels produced in the labial context, the boundary between front versus back perception was closer to the /u/ end of the continuum than for vowels produced in the alveolar context. This reflects compensation by listeners for the expected effects of coarticulation with the flanking consonants [Ohala and Feder, Phonetica 51, 111–118 (1994); Bradlow and Kingston, J. Acoust. Soc. Am. Suppl. 1 88, S56 (1990)]. [Work supported by NIH Grant No. 5-R29-DC01708.]
The phonological relationship between Taiwanese initial voiced stops and nasals.
Authors: Pan Ho-hsien
Published: October 2005

Taiwanese voiced stops are followed by non-nasalized vowels, while nasals are followed by nasalized vowels. This study uses a concept formation paradigm to test whether native speakers treat the voiced stops and nasals as allophones or separate phonemes. There are three experiments in the study. In the training session of experiment A, monosyllabic morphemes are presented. Subjects receive a positive reinforcement when a syllable beginning with /b/ is presented. In the test session of experiment A, syllables beginning with /m/ are introduced. In experiments B and C disyllabic phrases are presented. In the training session of test B, the subjects are reinforced to treat /b/ and /m/ as separate categories. In the training session of test C, the subjects are reinforced to treat /b/ and /m/ as the same category. The results show that /m,b/ are grouped into the same category. In experiment B, subjects cannot differentiate between /b/ and /m/. In experiment C, when /b/ and /m/ are reinforced to be of the same category, the subjects perform well. According to the interview responses after each test, subjects describe the category that is being reinforced positively as nasals.