Theory Of Acoustic Invariance Research Articles

Effects of speaking rate on the single/geminate stop distinction in Japanese

This study addressed an issue in the theory of acoustic invariance. The question was whether an invariant acoustic property exists for distinguishing Japanese single and geminate voiceless stops across rates and speakers. Four native Japanese speakers produced disyllabic words with single and geminate stops (e.g., /kako/ and /kak:o/) spoken in a carrier sentence at three speaking rates. Durations of sentences, words, stop closures, vowels preceding the contrasting stops, and voice onset times were measured. Ratios of geminate to single stop closures, geminate words to singleton words, closures to preceding vowels, and closures to words were calculated. The effect of rate on closure duration was to yield overlap between the singleton and geminate categories, and to lengthen geminate closures more than single closures as rate decreased. However, the ratio of geminate to single closure duration was unaffected by rate. Furthermore, the ratio of closure to word duration (0.35 as an optimal boundary) best classified all singleton and geminate tokens with 95.7%-98% accuracy. Thus, in spite of overlap in absolute closure duration between single and geminate voiceless stops, there is a relationally invariant measure that divides the two phonemic categories across rates and speakers, supporting the theory of relational acoustic invariance. co ustical Society of America.

Theoretical implications of the quantal nature of speech: a commentary

The relation between the quantal theory of speech and a theory of acoustic invariance and distinctive feature theory is considered. Certain aspects of the quantal theory are questioned including the role of the proximity of two formants in defining quantal regions and the extent to which there is an “abrupt” change in the boundary regions between two quantal regions. Nevertheless, it is argued that the quantal theory provides the basis for a theory of acoustic invariance and distinctive feature theory. Issues that have yet to be resolved include whether the same acoustic properties necessarily generalize across different sound classes, whether all distinctive features have their basis in quantal relations, whether the particular distinctive features proposed are the correct ones, and the exact characterization of the nature of the acoustic properties corresponding to the full set of distinctive features.

The vowel-dependence of gross spectral cues to place of articulation of stop consonants in CV syllables

It has been argued by Stevens and Blumstein that the acoustic cues of stop consonant place of articulation residing in the gross spectrum, sampled at the release burst onset, are invariant across different vowel contexts. It is shown in this paper that the conclusion of in variance does not follow from the experimental findings of the proponents of the theory of acoustic invariance, and the present results indicate that the vowel exerts a reliable influence on the stop–vowel waveform from the very beginning in terms of gross spectral properties. Also, the consonant influence is seen to be strong throughout the 45 ms interval from the beginning of the CV syllable. Implications of these coarticulatory effects to theories of speech perception are discussed.

On some issues in the pursuit of acoustic invariance in speech: a reply to Lisker.

This paper presents an alternative view of acoustic invariance in speech to that discussed by Lisker [J. Acoust. Soc. Am. 77, 1199-1202 (1985)]. Three points are considered--the minimal unit for acoustic invariance, the level of linguistic representation over which this unit operates, and the role that acoustic invariance plays in speech and language. Our position emphasizes the role of phonetic features in a theory of acoustic invariance, and we propose a series of working hypotheses to guide research in this area.