Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “PHONETICS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,063 records · Page 59Linked to original sources
PubMed1997

Adult and infant perception of two English phones.

Previous research has shown that young infants easily discriminate both native and non-native consonant contrasts, but by 10-12 months of age infants perform like adults and easily discriminate only native consonant contrasts. The present study was designed to determine what kind of experience is required to maintain discrimination of native consonants. To address this question, English listeners of three ages (6-8 months, 10-12 months, and adults) were presented with the phonetic difference, [da] vs [t = a]. This distinction occurs in English but is not phonemic: [t = a] occurs when it follows an [s] (as in /sta/). If passive exposure is sufficient to maintain discrimination, all age groups should discriminate [da] vs [t = a]. However, if phonological status plays a role, then older infants and adults should fail. In experiment 1, English adults judged [da] and [t = a] to be equally good instances of the same phonemic category /da/. In an AX procedure in experiment 2, English adults discriminated [da] vs [t = a] better than chance but worse than native phonemic levels. In the Conditioned Head Turn procedure in experiment 3, adults and 6- to 8-month-old infants discriminated [da] vs [t = a], but 10- to 12-month-old infants did not. Taken together, these results are most consistent with the hypothesis that phonological status plays a role in maintaining discrimination of phonetic information.

Adolescent↗
PubMed1998

Depolarizing the perceptual magnet effect.

In recent years there has been a great deal of interest in demonstrations of the so-called "Perceptual-Magnet Effect" (PME). In these studies, AX-discrimination tasks purportedly reveal that discriminability of speech sounds from a single category varies with judged phonetic "goodness" of the sounds. However, one possible confound is that category membership is determined by identification of sounds in isolation, whereas, discrimination tasks include pairs of stimuli. In the first experiment of the current study, identification and goodness judgments were obtained for vowels (/i/-/e/) presented in pairs. A substantial shift in phonetic identity was evidenced with changes in the context vowel. In a second experiment, listeners participated in an AX-discrimination task with the vowel pairs from the first experiment. Using the contextual identification functions from the first experiment, predictions of discriminability were calculated using the classic tenets of Categorical Perception. Obtained discriminability functions were well accounted for by predictions from identification. There was no additional unexplained variance that required the proposal of "perceptual magnets." These results suggest that PME may be nothing more than further demonstration that general discriminability is greater for cross-category stimulus pairs than for within-category pairs.

Humans↗
PubMed1999

A comparison of intergestural patterns in deaf and hearing adult speakers: implications from an acoustic analysis of disyllables.

Coarticulation studies in speech of deaf individuals have so far focused on intrasyllabic patterning of various consonant-vowel sequences. In this study, both inter- and intrasyllabic patterning were examined in disyllables /symbol see text #CVC/ and the effects of phonetic context, speaking rate, and segment type were explored. Systematic observation of F2 and durational measurements in disyllables minimally contrasting in vocalic ([i], [u,][a]) and in consonant ([b], [d]) context, respectively, was made at selected locations in the disyllable, in order to relate inferences about articulatory adjustments with their temporal coordinates. Results indicated that intervocalic coarticulation across hearing and deaf speakers varied as a function of the phonetic composition of disyllables (b_b or d_d). The deaf speakers showed reduced intervocalic coarticulation for bilabial but not for alveolar disyllables compared to the hearing speakers. Furthermore, they showed less marked consonant influences on the schwa and stressed vowel of disyllables compared to the hearing controls. Rate effects were minimal and did not alter the coarticulatory patterns observed across hearing status. The above findings modify the conclusions drawn from previous studies and suggest that the speech of deaf and hearing speakers is guided by different gestural organization.

Adult↗
PubMed1999

Cortical auditory evoked potential correlates of categorical perception of voice-onset time.

The goal of this study was to examine the neural encoding of voice-onset time distinctions that indicate the phonetic categories /da/ and /ta/ for human listeners. Cortical Auditory Evoked Potentials (CAEP) were measured in conjunction with behavioral perception of a /da/-/ta/ continuum. Sixteen subjects participated in identification and discrimination experiments. A sharp category boundary was revealed between /da/ and /ta/ around the same location for all listeners. Subjects' discrimination of a VOT change of equal magnitude was significantly more accurate across the /da/-/ta/ categories than within the /ta/ category. Neurophysiologic correlates of VOT encoding were investigated using the N1 CAEP which reflects sensory encoding of stimulus features and the MMN CAEP which reflects sensory discrimination. The MMN elicited by the across-category pair was larger and more robust than the MMN which occurred in response to the within-category pair. Distinct changes in N1 morphology were related to VOT encoding. For stimuli that were behaviorally identified as /da/, a single negativity (N1) was apparent; however, for stimuli identified as /ta/, two distinct negativities (N1 and N1') were apparent. Thus the enhanced MMN responses and the morphological discontinuity in N1 morphology observed in the region of the /da/-/ta/ phonetic boundary appear to provide neurophysiologic correlates of categorical perception for VOT.

Adult↗
PubMed2000

A self-learning predictive model of articulator movements during speech production.

A model is presented which predicts the movements of flesh points on the tongue, lips, and jaw during speech production, from time-aligned phonetic strings. Starting from a database of x-ray articulator trajectories, means and variances of articulator positions and curvatures at the midpoints of phonemes are extracted from the data set. During prediction, the amount of articulatory effort required in a particular phonetic context is estimated from the relative local curvature of the articulator trajectory concerned. Correlations between position and curvature are used to directly predict variations from mean articulator positions due to coarticulatory effects. Use of the explicit coarticulation model yields a significant increase in articulatory modeling accuracy with respect to x-ray traces, as compared with the use of mean articulator positions alone.

Adolescent↗
PubMed2000

Neighboring spectral content influences vowel identification.

Four experiments explored the relative contributions of spectral content and phonetic labeling in effects of context on vowel perception. Two 10-step series of CVC syllables ([bVb] and [dVd]) varying acoustically in F2 midpoint frequency and varying perceptually in vowel height from [delta] to [epsilon] were synthesized. In a forced-choice identification task, listeners more often labeled vowels as [delta] in [dVd] context than in [bVb] context. To examine whether spectral content predicts this effect, nonspeech-speech hybrid series were created by appending 70-ms sine-wave glides following the trajectory of CVC F2's to 60-ms members of a steady-state vowel series varying in F2 frequency. In addition, a second hybrid series was created by appending constant-frequency sine-wave tones equivalent in frequency to CVC F2 onset/offset frequencies. Vowels flanked by frequency-modulated glides or steady-state tones modeling [dVd] were more often labeled as [delta] than were the same vowels surrounded by nonspeech modeling [bVb]. These results suggest that spectral content is important in understanding vowel context effects. A final experiment tested whether spectral content can modulate vowel perception when phonetic labeling remains intact. Voiceless consonants, with lower-amplitude more-diffuse spectra, were found to exert less of an influence on vowel perception than do their voiced counterparts. The data are discussed in terms of a general perceptual account of context effects in speech perception.

Humans↗
PubMedDate not supplied

Vowel change in Australian English.

The dynamic nature of vowel systems has recently been investigated in several English dialects confirming that phonetic disruptions often have systemic consequences and suggesting that change follows predictable patterns of movement. The present paper examines the nature of vowel change in Australian English by comparing two sets of data from different subjects at each end of a 25-year interval. A series of multivariate analyses of variance reveals significant acoustic differences between the two sets of data providing strong evidence for systemic effects. The analysis also indicates the presence of chain and parallel shifts within vowel classes as well as a close correspondence between monophthong and diphthong movement in phonetic space. The observed monophthong/diphthong relationships suggests that change in one class of vowels impacts on the other in a parallel fashion in this dialect of English.

Adolescent↗
PubMed2005

Between fall and fall-rise: substance-function relations in German phrase-final intonation contours.

This study investigates an intonation contour of German whose status has not been established yet: a globally falling contour with a slight rise at the very end of the phrase (FSR). The contour may be said to lie on a phonetic continuum between falling (F) and falling-rising (FR) contours. It is hypothesized that F, FR and FSR differ with respect to their communicative functions: F is terminal, FR is non-terminal, and FSR is pseudo-terminal, respectively. The hypotheses were tested in two steps. First, measurements in a labelled corpus of spontaneous speech provided the necessary background information on the phonetics of the contours. In the second step, the general hypothesis was approached in a perceptual experiment using the paradigm of a semantic differential: 49 listeners judged 17 systematically generated stimuli on nine semantic scales, such as 'impolite/polite'. The hypotheses were generally confirmed. Both F and FSR were associated with a conclusive statement, while FR was more likely to be judged as marking a question. FSR differs from F in that it does not express features such as categoricalness, dominance or impoliteness. The results are interpreted as an instance of the frequency code: the addition of a slight rise means avoidance of extremely low F(0); the functional consequence is a reduction of communicated dominance.

Adult↗
PubMed1976

[Aspiration and glottal activity. Experimental test during production of Icelandic consonants].

The results of an experimental research of the glottal activity during the production of Icelandic consonants and consonant clusters are reported. The method of research is the photoglottography. It is concluded from the data examined that aspiration in Icelandic can be described as a function of glottal opening at the moment of release. The last part of the study contains a discussion of the place of phonetics in linguistic analysis. It is asserted that an analysis of the linguistic form always must precede a phonetic analysis.

Glottis↗
PubMed1977

[On "VOT": the case of Bourouchaski (author's transl)].

Our phonetic study of Bourouchaski shows that the homorganic plosives of this language cannot be distinguished by a specific difference in voice onset time (VOT). This finding leads us to the question whether this phonetic feature is of real interest not only for the phonological description of a language, but also in a more general sense for the theory of phonology.

Humans↗
PubMed1977

Emphasis in Telugu.

The phenomenon of emphasis is studied with regard to the phonetic variation of the vowel and consonant units of the word structure in Telugu, a Dravidian language spoken mainly in South India. The electro-aerometer and the mingograph are used to provide phonetic evidence. The study reveals that different means are used to emphasise words of different structures so that the phonological structure is not disturbed.

Humans↗
PubMed1979

[Speech sounds and speech signals--the perspective of a new phonometry (author's transl)].

Descriptive phonetics and instrumental phonetics have two entirely different empirical domains as their subject matters. On this basis, ZWIRNER's central problem of the theoretical relationship between sound category and sound realisation is re-formulated and discussed. It is shown how the traditional descriptive procedures of segmentation and decomposition can be connected with the segments of digital speech signals and the features analysed from them.

Humans↗
PubMed1981

Temporal information processing in speech perception.

For a set of formal rules for the phonetic interpretation of speech during its perception one should have data concerning a possible structure and parameters of a subjective mechanism for processing temporal information, from segmenting the speech signal to making phonetic decisions. At present such data cannot be found in the literature. An attempt has been made to find out more about some parts of the subjective mechanism of duration measurement and comparison by studying the perception of tempo changes in short sound sequences. Running or 'momentary' tempo is shown to be the feature of tempo change perception, and possible procedures for its detection have been tested. A computational technique for getting the quantitative parameters of the mechanism is briefly described.

Humans↗
PubMed1983

Parameter interaction in the perception of French plosives.

This investigation takes as its point of departure observations on the production of French fortis versus lenis plosive consonants. In a series of perception tests the role of different parameters in the fortis versus lenis distinction found in production (e.g. duration of the pre-consonantal vowel, the consonantal closure, voicing during the closure and intensity of the consonantal release noise) was investigated. Apart from durational and intensity parameters, vowel quality differences (depending on the fortis versus lenis character of the following consonant) are also shown to play a part in phoneme identification. Furthermore it is shown that in obstruent clusters like /tp, dp/ versus /tg, dg/ not only do phonetic parameters like those mentioned above influence perception, but that also the phonemic identity of /p/ versus /g/ as fortis versus lenis contributes to the hearers' decision about the identity of the first consonant in the cluster. Phonetic as well as contextual factors are shown to interact in a complex manner. Implications of the results for speech perception theory are discussed.

France↗
PubMed1983

What is the reference that sound durations are compared with in speech perception?

Speech segment durations are widely used as cues in the phonetic interpretation of speech (during its perception). To devise a system of quantitative rules for the automatic phonetic interpretation of natural speech it is necessary to know with what reference the speech sound duration is to be compared. An experiment with a specially arranged set of stimuli has shown that durations of adjacent sounds in an utterance, namely vowels, are used as the reference for word stress perception in Russian.

Cues↗
PubMed1985

Perception of speech rate of Dutch and Italian utterances.

The speech signal contains many linguistic and prosodic cues which determine the perception of speech rate. We investigated which cues could optimally explain rate judgements of short Dutch and Italian utterances. For this, the correlation between an objective measure of speech rate (linguistic syllables per second, phonetic syllables per second, or phonetic segments per second) and perceived speech rate has been evaluated for rate judgements of normal, monotone, and unintelligible utterances. The effect of language background on speech rate perception was also studied, by using Dutch and Italian listeners.

Cues↗
PubMed1985

On aspiration in Swahili: hypotheses, field observations, and an instrumental analysis.

Quantitative evidence to substantiate accounts of Swahili phonetics is scarce. In this paper, attention is drawn to the particularly complex feature of aspiration. A set of working hypotheses for experimental research are formulated. On the basis of field observations, aspiration is assumed to be operative at several levels of Swahili grammar. Contrary claims are reviewed and discussed in relation to informant selection and control methods for experimental procedures. A digital phonetic data base under current construction is outlined. Speech samples from the data base are used to quantify Swahili aspiration along the voice onset time dimension. The data suggest that the physical manifestation of the aspiration feature is relatively strong in Swahili as compared with Swedish.

Adult↗
PubMed1989

Dynamic information in the identification and discrimination of vowels.

The dynamic theory of vowel perception emphasizes the importance of the consonant transitions in CVC syllables to the identification of the vowel itself. However, the dynamic theory is relatively vague in terms of what perceptual processes may be involved and it says nothing about the role of auditory and/or phonetic memory for such 'dynamic events'. The present study created three synthetic [iota]-[epsilon] continua consisting of a [bVb] full-syllable continuum, a silent-center continuum (which had over 72% of the medial vowel replaced by silence) and an isolated vowel continuum to specifically examine (1) the use of auditory and phonetic memory for dynamic acoustic cues and (2) the ability of listeners to track the trajectories of very brief formant transitions. Experiment 1 demonstrated that there were no significant differences among the three continua in terms of listener identifications but that the silent-center tokens demonstrated significantly lower within-category discriminations, perhaps because of degraded auditory representation. Experiment 2 required listeners to make cross-continuum vowel discriminations and showed that some degree of acoustic similarity was important--listeners were particularly poor at discriminating between the silent-center and vowel-only tokens. This suggests that listeners were not able to make discriminations on the basis of abstract vowel labels alone. Experiment 3 demonstrated that listeners could make quite accurate vowel identifications even when as little as 1 pitch period of acoustic energy signaled the consonant transitions in the silent-center tokens. Experiment 4 showed that listeners' identifications of the silent-center stimuli were based on the formant changes in the transitions rather than their endpoint frequencies.

Cues↗