Volume 55, Issue 4

Previous studies have reported that F₀ contours of lexical tones in Mandarin are closely aligned with the syllables that carry them and that this alignment is late-adjusted so that the most appropriate F₀ contour of a tone occurs mainly in the later portion of the host syllable. These studies, however, examined tone alignment only in syllables with a simple CV structure. The present study compared tone-syllable alignment patterns in syllables with a final nasal (the only final consonant allowed in Mandarin) to those without a final nasal at three speaking rates – normal, fast and slow. Experiment 1 found that regardless of internal syllable structure, the F₀ contours for all of the four Mandarin tones maintain a consistent alignment to the syllables that carry them. Experiment 2 found that whether or not the syllable has a final nasal and regardless of speaking rate, the F₀ peak associated with the R (rising) tone always occurs near the offset of the R-tone-carrying syllable, the onset of the F₀ rise always occurs near the center of the syllable and the slope of the rise does not vary systematically with either syllable structure or speaking rate. These findings are interpreted as indicating that the syllable is the proper domain for tone implementation and that tone contours such as rising and falling are probably implemented as integral dynamic targets rather than as sequences of static targets.

Locus equations were employed to assess the phonetic stability and distinctiveness of stop place categories in reduced speech. Twenty-two speakers produced stop consonant + vowel utterances in citation and spontaneous speech. Coarticulatory increases in hypoarticulated speech were documented only for /dV/ and [gV] productions in front vowel contexts. Coarticulatory extents for /bV/ and [gV] in back vowel contexts remained stable across style changes. Discriminant analyses showed equivalent levels of correct classification across speaking styles. CV reduction was quantified by use of Euclidean distances separating stop place categories. Despite sensitivity of locus equation parameters to articulatory differences encountered in informal speech, stop place categories still maintained a clear separability when plotted in a higher-order slope × y-intercept acoustic space.

The onset of canonical babbling (CB) is a landmark event in infants’ vocal development for spoken language. Previous research has suggested that the onset of CB coincides with the peak period of rhythmic activities. To examine this phenomenon in detail, 28 Japanese infants (14 girls, 14 boys) were observed longitudinally from the age of 5 to 9 months. In the experimental sessions, an audible or an inaudible rattle was placed into a hand of each tested infant. Then the number of times that the infant shook the rattle was counted. In the observational sessions, infants’ spontaneous rhythmic activities under natural conditions were observed. The result shows that rhythmic activities reached their peak around the onset of CB. When the infants began to babble, they shook whichever rattle was in their hand, regardless of its audibility. After this period, they shook the audible rattles more frequently than the inaudible ones. These findings suggest that, around the onset of CB, infants learn to control their motor activities based on auditory feedback.