Volume 50, Issue 1

Much of the published research in infant speech perception has emphasized how well infants have done with a number of speech contrasts, and have noted similarities in pattern of discrimination of adults and infants. Often it has been suggested that infants begin life with the ability to perceive any speech contrast, and that the process of acquiring a language involves inhibition of the ability to perceive contrasts not present in the target language. Indeed some studies have shown infants able to discriminate contrasts on which adults fail if the contrasts are not drawn from the native language of the adults. Other studies, however, have suggested that infants may not always be so perceptually capable. The present work focusses on the stop-glide contrast. The results are inconsistent with the prevalent view and with previously reported studies on the perception of the stop-glide contrast by infants. The results indicate that in a vigilance paradigm adapted for both infant and adult testing, infants perform poorly on the contrasts when compared with adults. Furthermore the pattern of relative perception observed in the adults on stimuli with long or short vowels is quite unlike that of the infants. It is concluded that much work remains in order to evaluate the relative performance of infants and adults in speech perception, since it appears that changes in experimental paradigm or particular stimulus parameters may affect outcomes in fundamental ways.

In this study, a multidimensional scaling (MDS) analysis was performed to investigate perceptual discrimination by listeners among normal female voices. Speech pathologists and untrained listeners rated the similarity of all possible pairings of 20 female voices presented in sentences. MDS analyses were performed on these data. To interpret the resulting dimensions, listeners additionally evaluated each voice on each of 17 rating scales. For each listener group, the normalized and averaged perceptual ratings were correlated with MDS stimulus coordinates for the 20 voices. This procedure resulted in a five-dimensional solution which best explained the speech pathologists’ similarity-dissimilarity judgements, with the following perceptual correlates for each dimension: (1) perceived pitch, (2) perceived loudness, (3) perceived age and duration of the speakers’ stimulus sentence, (4) perceived variability, and (5) perceived quality. The untrained listeners’ judgements were best explained by a two-dimensional solution. Comparisons with other MDS studies were made, and the need for new acoustic measures was discussed.

The present study examined regressive voice assimilation in Catalan in an attempt to determine a systematic explanation of complete versus incomplete voicing neutralization. Two types of contexts were constructed. In one type, semantic information was present to bias the meaning of target words. In the other type, no semantic information was present. The results showed that vowel duration distinguished underlying voicing in the neutral context only. The results suggest that neutralization occurs when semantic information is present, but that a voicing contrast is realized when it is absent.

This study investigates durational differences in syllable-final nasals in Japanese, English, and Korean, and examines the mora hypothesis in Japanese. The phenomenon that syllable-final nasals are longer when followed by a voiced consonant than when followed by a voiceless consonant was observed in languages of different timing categories, i. e. Japanese (moratimed), Korean (syllable-timed), and English (stress-timed). However, syllable-final nasals in Japanese (the mora nasal /n/) are set apart with respect to the moraic status: syllable-final nasals (moraic) are clearly differentiated in duration from syllable-initial nasals (non-moraic).