A performance constraint on compensatory lengthening in child phonology

Area of Science:

• Linguistics
• Child Language Acquisition
• Phonology

Background:

• Young children's mispronunciations often mimic adult phonological rules, leading to analysis as identical data.
• Phonological theory distinguishes between 'hard' (absolute) constraints and 'soft' (context-dependent) performance constraints.
• Compensatory lengthening, where a segment lengthens upon deletion of a neighbor, is a key phonological process observed in child speech.

Purpose of the Study:

• To investigate the role of performance constraints in child phonology, specifically compensatory lengthening.
• To analyze why compensatory lengthening produced [i:] but not [u:] in one child's speech.
• To argue for the necessity of incorporating performance factors into models of child phonology.

Main Methods:

• Analysis of spontaneous speech data from a single child exhibiting systematic mispronunciations.
• Identification and categorization of phonological processes, focusing on compensatory lengthening.
• Comparison of the distribution of lengthened vowels ([i:] vs. [u:]) and the timing of vowel and glide acquisition.

Main Results:

• Compensatory lengthening resulted in the creation of long front vowels ([i:]) but never long back rounded vowels ([u:]).
• The child correctly produced adult /u:/, indicating the absence of a 'hard' phonological constraint against this sound.
• Later mastery of back rounded vowels and glides compared to front counterparts was observed.

Conclusions:

• Soft performance constraints, specifically an aversion to back rounded segments, prevented the creation of [u:] via compensatory lengthening.
• Phonological theory's hard constraints alone cannot explain the observed data; performance factors are crucial.
• Accurate descriptions of child phonology necessitate the inclusion of performance limitations alongside linguistic rules.