A developmental study of vowel perception from brief synthetic consonant–vowel syllables

Abstract

The purpose of this study was to assess the perceptual role of brief synthetic consonant-vowel syllables as cues for vowel perception in children and adults. Nine types of consonant-vowel syllables comprised of the stops [b d g] followed by the vowels [i a u] were synthesized. Stimuli were generated with durations of 10, 30, or 46 ms, and with or without formant transition motion. Eight children at each of five age levels (5, 6, 7, 9, and 11 years) and a control group of eight adults were trained to identify each vowel in a three-alternative forced-choice (3AFC) paradigm. The results showed that children and adults extracted vowel information at a generally high level from stimuli as brief as 10 ms. For many stimuli, there was little or no difference between the performance of children and adults. However, developmental effects were observed. First, the accuracy of vowel perception was more influenced by the consonant context for children than for adults. Whereas perception was similar across age levels for stimuli in the alveolar context, the youngest children perceived vowels in the labial and velar contexts at significantly lower levels than adults. Second, children were more affected by variations in stimulus duration than were adults. This finding was particularly prominent for the syllable [ga], where the dependency on duration decreased with age in a nearly linear fashion. These findings are discussed in relation to current hypotheses of vowel perception in adults, and hypotheses of speech perception development.

Impairments in speech and nonspeech sound categorization in children with dyslexia are driven by temporal processing difficulties

“…At the nonspeech level, this is in line with (1) physiological animal studies showing that neural coding for temporal aspects of the stimulus reaches maturity later than neural coding for frequency selectivity (Eggermont, 1996), and with (2) behavioral auditory studies in humans providing evidence for a more prolonged development of the sensitivity for temporal than for nontemporal auditory cues (Hartley, Wright, Hogan, & Moore, 2000), even after accounting for the effect of procedure-related skills (Dawes & Bishop, 2008). At the speech level, it coincides with behavioral speech perception studies demonstrating that the identification of stop consonants is not yet mature by the age of 11 (Hazan & Barrett, 2000;Johnson, 2000;Krause, 1982;Simon & Fourcin, 1978;Medina, Hoonhorst, Bogliotti, & Serniclaes, 2010), whereas the identification of vowels does only slightly, though not significantly, improves towards adolescence (Pursell, Swanson, Hedrick, & Nabelek, 2002;Ohde, Haley, & McMahon, 1996;Johnson, 2000, but see Walley and Flege, 1999). Further elaboration on this topic is needed, but the indication that perception of sounds with temporal versus nontemporal cues follows different maturational trajectories in both normal and dyslexic readers, may have practical implications with regard to auditory temporal training programs.…”

Formant onsets and formant transitions as developmental cues to vowel perception

“…However, contrary to this view, some prior developmental results might be interpreted to support a formant target model (Sussman, 2001). Ohde et al (1996) speculated that "vowels may be apprehended as unique perceptual units early in development," because even young infants can perform speaker normalization. Infants have demonstrated an ability to discriminate vowel signals regardless of age, gender, etc.…”

“…of the speaker and can even link acoustic to facial cues by four months of age (Kuhl, 1979(Kuhl, , 1983. Only a few other studies have been conducted specifically on the development of vowel perception (Parnell and Amerman, 1978;Murphy et al, 1989;Ohde et al, 1996;Ohde and Haley, 1997;Malech and Ohde, 2003). Of these studies, none have examined potential differences in cue weighting of vowels in children compared to adults.…”

“…Other investigators have also concluded that young children appear to use dynamic cues such as formant transitions relatively more than do adults in identifying fricatives (Nittrouer, 1996), glides (Bourland Hicks and Ohde, 2005), and vowels (Murphy et al, 1989;Nittrouer, 1996;Ohde et al, 1996;Ohde and Haley, 1997;Malech and Ohde, 2003), especially the latter. Nittrouer (1996) termed this perceptual process the Developmental Weighting Shift.…”

Percepção da fala em bebês no primeiro ano de vida

“…O conhecimento acumulado sobre percepção de fala ressalta também o desenvolvimento como importante aspecto nesta competência perceptual (Montgomery & Clarkson, 1997;Ohde, Haley, & McMahon, 1996). Já ao nascimento o bebê possui capacidade de detectar contrastes consonantais, por exemplo, sendo esta habilidade não apenas inata, mas característica do sistema auditivo dos mamíferos.…”