Consonant‐vowel interactions in developmental phonological disorder

Abstract

This paper presents examples of consonant‐vowel interactions collected from a group of Edinburgh children presenting with developmental phonological disorder. Three types of interaction are described: vowel conditioning of consonant production, consonant conditioning of vowel production and use of consonantal material to maintain vowel contrasts. Evidence of context conditioning in both consonant and vowel error patterns highlights the potential importance of assessing the child's sound system as a whole. It also raises the question of how far coarticulatory constraints play a role in phonological disorder. In this paper, the data are interpreted, where possible, in terms of production constraints and the degree of compatibility between consonant and vowel gestures. This approach represents one particular perspective and is not intended to preclude other perceptual and/or phonological accounts of the data.

Context Conditioned Error Patterns in Disordered Systems

“…The following two cases represent a departure from the typical pattern of front/back vocalic influence in that velars are fronted preceding back rounded vowels but appear as velar before front vowels (Table 5-7). In the first case reported by Bates and Watson (1995) Child SC's sound system was characterized by widespread variability with the exception of this particular contextsensitive error pattern. In a study of consonant cluster acquisition (Scobbie, Gibbon, Hardcastle, and Fletcher 1998;2000), unpublished data from Child DB shows that his realizations of /st/ and /sk/ are partly context-sensitive (Table 5-8).…”

“…The most commonly reported CV effect in the literature is the lowering/backing of front vowels in the context of a following velarized lateral [~] (Bates, Hewlett, Kaighin, et al, 1992;Bates and Watson, 1995;Gibbon, Shockey, and Reid, 1992;Pollock and Keiser, 1990;Reynolds, 1990). In their group study, Bates and Watson (1995) found examples of this process in the systems of three children (Table 5-10).…”

“…Correct fricative production was arguably facilitated by the back rounded vowel context, which shares the consonant's specification for labiality. Following Lindsey and Harris (1995), Bates and Watson (1995) . Again, this pattern may be interpreted as target overshoot, given the conflicting demands on jaw/lip position for the consonant and vowel gestures.…”

“…The phonetic models provide a biological perspective insofar as the immature pronunciations of the normally developing child are viewed as systematic reflections of organic constraints imposed by the child's developing phonetic systems, both perceptual and motor. In the clinical setting, context conditioning manifests itself most frequently as consonantal speech errors, which only occur in specific vocalic contexts, although recent research has also uncovered evidence of vowel errors conditioned by consonantal context (Bates and Watson, 1995;Reynolds, 1990). Such interdependencies accord well with current phonetically orientated models of speech acquisition and have important implications for clinical practice.…”

“…In the clinical setting, context conditioning manifests itself most frequently as consonantal speech errors, which only occur in specific vocalic contexts, although recent research has also uncovered evidence of vowel errors conditioned by consonantal context (Bates and Watson, 1995;Reynolds, 1990). Such interdependencies accord well with current phonetically orientated models of speech acquisition and have important implications for clinical practice.…”