The role of temporal and dynamic signal components in the perception of syllable-final stop voicing by children and adults

Abstract

Adults whose native languages permit syllable-final obstruents, and show a vocalic length distinction based on the voicing of those obstruents, consistently weight vocalic duration strongly in their perceptual decisions about the voicing of final stops, at least in laboratory studies using synthetic speech. Children, on the other hand, generally disregard such signal properties in their speech perception, favoring formant transitions instead. These age-related differences led to the prediction that children learning English as a native language would weight vocalic duration less than adults, but weight syllable-final transitions more in decisions of final-consonant voicing. This study tested that prediction. In the first experiment, adults and children (eight and six years olds) labeled synthetic and natural CVC words with voiced or voiceless stops in final C position. Predictions were strictly supported for synthetic stimuli only. With natural stimuli it appeared that adults and children alike weighted syllable-offset transitions strongly in their voicing decisions. The predicted age-related difference in the weighting of vocalic duration was seen for these natural stimuli almost exclusively when syllable-final transitions signaled a voiced final stop. A second experiment with adults and children (seven and five years old) replicated these results for natural stimuli with four new sets of natural stimuli. It was concluded that acoustic properties other than vocalic duration might play more important roles in voicing decisions for final stops than commonly asserted, sometimes even taking precedence over vocalic duration.

Issues in human auditory development

“…However, all age groups, and particularly the 5-year-olds, improved with training. Nittrouer and her colleagues have published a series of studies that documents differences between preschool children and older listeners in the cues that they use in phonetic discriminations (e.g., Nittrouer, 2004Nittrouer, ,2005Nittrouer, ,2006. In general, the results of these studies support the view that children place greater weight on dynamic cues than on static cues in identifying and discriminating consonants when both types of cues are available, but that adults do just the opposite, weighting static cues more heavily than dynamic cues.…”

Auditory short-term memory trace formation for nonspeech and speech in SLI and dyslexia as indexed by the N100 and mismatch negativity electrophysiological responses

“…Two sets of synthetic stimuli, speech and non-speech (closely resembling those used by [19]), were created by using a Klatt type cascade-parallel formant synthesizer (HLsyn, Sensimetrics Inc., 1.0). Speech stimuli were English nonwords /bot/ and /bod/ that are distinguished by voicing of the syllable-final consonant.…”

Using speech sounds to test functional spectral resolution in listeners with cochlear implants

“…Synthetic speech permits rigorous control, but there are some issues that limit the utility of this approach. For instance, synthetic speech is consistently less intelligible than natural speech (Greene et al, 1986), and there are several published studies suggesting that listeners perceive spectral and temporal cues in synthetic speech in a qualitatively different way than in natural speech (Walsh and Parker, 1984;Hillenbrand et al, 2000;Nittrouer, 2004). Across these studies, spectral cues like formant structure and formant transitions were weighted less heavily in synthetic speech compared to natural (or modified natural) speech, presumably because of limitations in the ability to synthesize natural-sounding voices, or limitations in assessing all of the relevant details of the speech spectrum.…”