A series of studies was undertaken to examine how rate normalization in speech perception would be influenced by the similarity, duration, and phonotactics of phonemes that were adjacent or distal from the initial, target phoneme. The duration of the adjacent (following) phoneme always had an effect on perception ofthe initial target. Neither phonotactics nor acoustic similarity seemed to have any influence on this rate normalization effect. However, effects of the duration of the nonadjacent (distal) phoneme were only found when that phoneme was temporally close to the target. These results suggest that there is a temporal window over which rate normalization occurs. In most cases, only the adjacent phoneme or adjacent two phonemes will fall within this window and thus influence perception of a phoneme distinction.One of the fundamental issues in speech perception research involves the apparent lack of invariance between the acoustic signal and the listener's perception. Listeners somehow manage to perceive messages correctly, despite the variability in the acoustic signal caused by changes in speaking rate, talkers, and dialect. Researchers often have tried to examine each of these issues separately, in the hope that they would later be able to combine their findings into one theory.One of the sources of variability in the acoustic signal is the rate at which a person speaks. People do not talk at a constant rate, and certain phonemes change substantially in duration as speaking rate changes (Crystal & House, 1982, 1990Miller, Grosjean, & Lomanto, 1984; or see Miller, 1981, for a review of earlier work). In addition, talkers differ in their intrinsic rate ofspeech (see Crystal & House, 1988d), and some dialects either lengthen sounds or shorten them. The issue ofrate change is especially important because some phonemic contrasts are cued, in whole or in part, by their duration. For instance, the fbl-/wl manner contrast can be cued by differences in duration alone, with shorter initial transitions being heard as more "b-like" and longer transitions as more "w-like" (Liberman, Delattre, Gerstman, & Cooper, 1956;Miller & Liberman, 1979). However, when we listen to someone who talks very quickly, we still hear Iwl phonemes: they do not all sound like stops. Conversely, when we listen to someone who speaks very slowly, intended fb/s do not all sound like Iw/s. Miller and Baer (1983) analyzed the transition This research was supported by NIDCD Grant RO 1-DC00219 to SUNY at Buffalo and by a National Science Foundation Graduate Fellowship to the first author. Some of these data were previously presented at the 123rd meeting of the Acoustical Society of America, May 1992, in Salt Lake City, and at the 124th meeting of the Acoustical Society of America, October 1992, in New Orleans. Comments may be sent to either author at the Department of Psychology, Park Hall, SUNY at Buffalo, Buffalo, NY 14260 (e-mail: rochelle@art.fss.buffalo.edu).durations for Ibal and Iwal and found that for a given speaking rate, Iwl transition...
Previous research on spoken word recognition has demonstrated that identification of a phonetic segment is affected by the lexical status of the item in which the segment occurs. W. F. Ganong (1980) demonstrated that a category boundary shift occurs when the voiced end of 1 voice-onset time continuum is a word but the voiceless end of another series is a word; this is known as the "lexical effect." A series of studies was undertaken to examine how lexical neighborhood; in contrast to lexical status, might influence word perception. Pairs of nonword series were created in which the voiced end of 1 series had a higher frequency-weighted neighborhood density, whereas the reverse was true for the other series. Lexical neighborhood was found to affect word recognition in much the same way as lexical status.
The results of experiments using selective adaptation with stop consonants have been interpreted in terms of auditory feature detector fatigue, phonetic feature detector fatigue, and response contrast. In the present studies, both a selective adaptation procedure and a procedure involving paired comparisons between successively presented stimuli were used to sort out these explanations. A fricative-stop-vowel syllable ([spa]) was constructed using an [s], followed by 75 msec of silence, followed by a 10-msec voice onset time [ba]. The perceived phonetic identity of this syllable was [p] even though the spectral structure of the stop vowel within this syllable was identical to a stimulus from the [ba] end of a [ba]-[pha] test series. As adaptors, the [spa] and [ba] endpoint syllables had identical effects. In paired-comparison procedure, the [spa] caused an ambiguous test item to be labeled "B," whereas the [ba] caused the test item to be labeled "P." Results of these experiments indicate that neither response contrast nor phonetic feature detection are involved in selective adaptation effects found for a voicing stop-consonant series. Results are interpreted as supporting the position that selective adaptation effects arise at an early, auditory level of processing that is responsive to the spectral overlap between adaptor and test items.
Recent accounts of selective adaptation in speech perception have proposed that either one or two levels of processing are adapted. Most of the previous experimental results can, however, be accounted for by either type of model. In the present experiments, two aspects of the selective adaptation paradigm were manipulated. The spectral (frequency) overlap between adapting and test syllables was manipulated along with differences in interaural presentation (adapting in one ear, testing in the other). The results indicated that the adapting syllables drawn from the test series and adaptors with no spectral overlap with the test series both produced significant changes in subjects ratings of the test stimuli. However, the identical adaptors caused significantly more adaptation than the nonoverlapping adaptors. Moreover, the nonoverlapping adaptors produced 100% interaural transfer of adaptation, indicating a central locus of this effect. The identical adaptors drawn from the test series showed approximately 50% interaural transfer. Taken together, these results strongly suggest that two levels of processing are involved in selective adaptation to place of articulation in stop consonants. One is a peripheral level that is relatively frequency specific and the other is a central level that integrates information over a wider frequency (spectral) range.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.