摘要:

The effects of voicing, manner, and number of consonants on the duration of previous vowels in English can be created in three ways: by planned expansion or contraction of the entire vowel, by changing the relative timing of consonant and vowel gestures, or by modifying the duration of the closing movement for the consonants. An X-ray micro-beam data base of 2 speakers of American English reciting monosyllabic words, which differed in their final consonants and in their position in the accentual structure of the utterance, was studied to evaluate these three accounts. In this data base, vowel duration differences due to the voicing of the following consonants were amplified by the presence of accent. Also, many of the duration differences associated with the following consonants are localized in the later portion of the opening movement, suggesting that subjects often create vowel duration changes by initiating the consonant closing gesture at an earlier or later time relative to the opening gesture.

ISSN:0031-8388    

DOI:10.1159/000261868

出版商:S. Karger AG    

年代:1991

数据来源: Karger

摘要:

An acoustic study of English initial voiced stops showed that the three place categories are well distinguished on the basis of three properties: second-formant onset frequency (F2 onset), second-formant frequency of the vowel nucleus (F2), and third-formant onset frequency (F3 onset). Ten male and 10 female subjects produced multiple tokens of /bVt/, /dVt/, and /gVt/ with ten different medial vowels. Three-dimensional scatterplots were generated using the above acoustic properties as coordinates. Three nonoverlapping clusters corresponding to the three place categories were evident across all subjects. Discriminant analyses based on F2 onset, F2 vowel, and F3 onset as predictor variables showed a mean correct categorization rate of 84.5% when tested within gender groups. The graphic and statistical results are interpreted as indicating that phonetic categories may be defined and represented in purely acoustic terms if variably valued multiple acoustic properties are relationally examined.

ISSN:0031-8388    

DOI:10.1159/000261869

出版商:S. Karger AG    

年代:1991

数据来源: Karger

摘要:

Research in speech perception has suggested that listeners often adjust category boundary locations for differing contexts. The stop/glide (e.g., /ba/ vs. /wa/) boundary shift occurring with changes in syllable duration has been interpreted as reflecting ‘rate normalization’ by some, whereas others have suggested an auditory basis for the shift. Clarification of both the causes and the effects of the stop/glide shift is being sought through experimentation intended to expand our knowledge of variations in the shift across different experimental treatments. The present study extends research on the stop/ glide shift by (1) showing that the shift is not an artifact of a particular stimulus pattern that had been present in all the previous studies of the effect, (2) further demonstrating the nonlinear character of the identification shift, (3) providing additional evidence of the role of presentation format (mixed vs. blocked) in the identification shift, and (4) exploring boundary locations in various discrimination paradigms. The complex outcomes of the studies reported here as well as a variety of previous results are interpreted as compatible with expanded versions of the durational contrast hypothesis. Two versions are considered, one in which the shift is seen as due to a mechanism of contrastive perception that applies to events of comparable duration, and one in which the shift is seen as a perceptual error that occurs when the auditory system attempts to track frequency trajectories that change (i.e., pivot) over t

ISSN:0031-8388    

DOI:10.1159/000261870

出版商:S. Karger AG    

年代:1991

数据来源: Karger

摘要:

The effect of differences in speaking rate on the duration of key words in phrase-final and sentence-final positions was investigated in order to reexamine the absence of utterance-final lengthening in Hebrew. Two native speakers of Hebrew read the original sentences at a relatively slow rate of speaking and at a relatively fast speaking rate. Whereas at the faster rate of speaking, key words in sentence-final position were longer than those in phrase-final position, no evidence for utterance-final lengthening surfaced at the slower rate of speaking. Lengthening in phrase-final position at the slower speaking rate was more than twice that in sentence-final position and occurred independently of pausing. The masking of utterance-final lengthening by phrase-final lengthening at the slower rate of speaking accounts for the original finding of cross-language differences in final lengthening. A relatively small number of pauses were produced following the phrase-final key word at the slower speaking rate, and phrase-final lengthening as a function of a slower tempo was independent of pausing. No differences were found between the magnitude of utterance-final lengthening and lengthening at a slower rate of speaking, indicating that the two processes exert a similar effect on duration.

ISSN:0031-8388    

DOI:10.1159/000261871

出版商:S. Karger AG    

年代:1991

数据来源: Karger

ISSN:0031-8388    

DOI:10.1159/000261872

出版商:S. Karger AG    

年代:1991

数据来源: Karger

ISSN:0031-8388    

DOI:10.1159/000261873

出版商:S. Karger AG    

年代:1991

数据来源: Karger

ISSN:0031-8388    

DOI:10.1159/000261874

出版商:S. Karger AG    

年代:1991

数据来源: Karger