Categorical labeling of synthetic /I/ and /ε/ in adults and school-age children

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.…”

Vowel perception and production in adolescents with reading disabilities

“…As noted earlier, one could investigate different sets of vowels, both phonetically similar and those that are less similar. Also, given cross-sectional findings of developmental differences in vowel discrimination (e.g., Pursell, et al, 2002), it would be of interest to examine the relationships between vowel perception/production and reading abilities in different age groups. Through this type of investigation, one could also examine the differential effects of remediation on vowel categorization and reading abilities.…”

“…Although vowels are perceived less categorically than stop consonants and have been found to be organized around a best representative or "prototype" (e.g., Kuhl, 1991), it is still possible to conduct identification tasks to see how consistently they are perceived. The /i/-/¢/ pair was used by Pursell, Swanson, Hedrick, and Nabelek (2002) to investigate the influence of maturity on the perception of these vowels. The researchers tested the ability of adults, 10-year-olds and five-to six-year-olds to identify the synthetic vowels /ff and /e/.…”