Volume 45, Issue 1

It is shown that within-speaker variations in vocal effort and phonation affect fundamental frequency (F₀) and the formant frequencies of vowels in the sense of a linear compression/expansion of the spectral separations between them, given an adequate scaling of pitch. Between-speaker variations in size correspond to a translation of the spectral peaks shaped by F₀ and the formants if pitch is scaled tonotopically (in Bark). On the basis of these observations, invariant cues to vowel quality are suggested. It is further shown that vowels produced by adult women tend to be phonetically more explicit and, hence, more peripheral in ‘vowel space’ than those of men and children. It is also shown that the formant frequencies of vowels subjected to paralinguistic variation are related by power functions of frequency.

A multidimensional scaling experiment was conducted to determine the perceptual structure of 11 American English vowels produced by a competent esophageal speaker. Estimates of perceptual distance among these vowels were obtained using a 9-point similarity/dissimilarity scale and were analyzed using an individual differences scaling algorithm (INDSCAL). A three-dimensional perceptual space was produced. The three perceptual dimensions corresponded to tongue advancement, vowel height, and rhotacization. These three dimensions were then correlated with selected bark scale transformed acoustic vowel measurements. The perceptual dimensions 1–3 corresponded most closely to F₃-F₂, F₁-F₀, and F₃, respectively. Little difference was found between the perceptual structure of esophageal vowels and laryngeal vowels, although it is suggested that the correlation between some of the acoustic measures (such as F₀) and the perceptual dimensions may change as a function of individual speaker differences due to postsurgical capabilities (anatomical and physiological) and/or method of voice restoration.

The purpose of the present study is to test the perceptual reality of allophonic variation and harmony in Indonesian. Indonesian listeners with different regional backgrounds were asked to predict word identity (CVCV or CVCVC) based on the presence or absence of vowel allophony and harmony. The data show that listeners were sensitive to the spectrally different allophones, but were not in all cases able to use this information in predicting word identity, probably due to experimental artifact.

Much of the perceptual information for a stop consonant in an [s]-stop cluster inheres in temporal properties of the acoustic signal local to the period of low energy corresponding to stop closure. However, stop percepts in this context are also influenced by the rate of speech in a precursor phrase to which the cluster is appended. The two experiments in this paper attempt to explore the dissociability of these local and longer-term perceptual influences, and to investigate the interactions between them. The results of the experiments reveal a complex pattern of interactions which suggests that a simple distinction between segmental and suprasegmental temporal information for phonetic contrasts is unrealistic.