Developmental and gender-related trends of intra-talker variability in consonant production

Abstract

This study investigates the effect of age and gender on the internal structure, cross-category distance, and discriminability of phonemic categories for two contrasts varying in fricative place of articulation (/s/-/∫/) and stop voicing (/b/-/p/) in word-initial tokens spoken by adults and normally developing children aged 9-14 yr. Vast between- and within-talker variability was observed with 16% of speakers exhibiting some degree of overlap between phonemic categories-a possible contribution to the range of talker intelligibility found in the literature. Females of all ages produced farther and thus more discriminable categories than males, although gender-marking for fricative between-category distance did not emerge until approximately 11 yr of age. Children produced farther yet also much more dispersed categories than adults with increasing discriminability with age, such that by age 13, children's categories were no less discriminable than those of adults. However, children's ages did not predict category distance or dispersion, indicating that convergence on adult-like category structure must occur later in adolescence.

An Ultrasound Study of the Development of Lingual Coarticulation during Childhood

“…While this within-group difference needs to be interpreted with caution due to the fact that 9-year-olds as a group did not have significantly less coarticulation on /ʃ/ than 7-year-olds or more than 11-year-olds, this pattern might represent ongoing changes in motor control, related to the vocal tract maturation (cf. Zharkova et al, 2011;Romeo et al, 2013). It also needs to be acknowledged that this study reports production data up to early adolescence, but not for older adolescent and adult productions.…”

“…Both these theories are compatible with the premise that children's productions are limited by their general motor abilities, which undergo continuous development during childhood. Such protracted maturation of speech motor abilities, in particular, has been demonstrated in a number of acoustic and articulatory studies (e.g., Smith and Goffman, 1998;Walsh and Smith, 2002;Koenig et al, 2008;Zharkova et al, 2011Zharkova et al, , 2012Romeo et al, 2013;Zharkova et al, 2014). For the children in their first 2 years of life, the dependence of speech production on developing motor skills has been formulated in terms of language-specific "opportunities and challenges" (Vihman, 2010, p. 279), which enhance or inhibit, respectively, the likelihood of children's phonetic realisations corresponding to adult targets (see also Vihman, 2014).…”

A comparison of spectral estimation methods for the analysis of sibilant fricatives

“…The values for the parameters a, K, and NW were chosen to match previous studies of sibilants (cf. Jongman et al, 2000, who pre-emphasized with a ¼ 0.98; Romeo et al, 2013, who computed MT spectra with K ¼ 8 and NW ¼ 4). From each spectral estimate, two spectral features were computed to assess how estimation method reveals different aspects of a spectrum's shape.…”

Spectral dynamics of sibilant fricatives are contrastive and language specific

“…Yet, a number of studies, using only static spectral measures, have sought to characterize the development of a child's productive knowledge of how a phonological sibilant contrast is implemented phonetically (e.g., Fox and Nissen, 2005;Li, 2012;Li et al, 2009;McGowan and Nittrouer, 1988;Nissen and Fox, 2005;Nittrouer et al, 1989;Romeo et al, 2013). Since the spectral patterns that must be acquired and produced by a language learner are dynamic in nature, the view of acquisition provided by static measures is likely incomplete.…”

“…The continuous movement of the tongue and jaw suggests that the generated turbulence noise may not be stationary; however, many acoustic studies of sibilant fricatives have characterized them in terms of static spectral properties, computed from either a single window of the fricative noise, or by averaging multiple windows placed across the fricative (e.g., Brunner et al, 2011;Ghosh et al, 2010;Holliday et al, 2015;Li, 2012;Li et al, 2009;Newman et al, 2001;Perkell et al, 2004;Romeo et al, 2013). Relatively little effort has been given to characterizing the temporal variation in spectral properties of sibilant fricatives across their duration.…”