The effects of jaw surgery on bilingual speech

Abstract

Surgery designed to correct misalignments of the jaw may lead to changes in the fine phonetic detail of speech segments. In some cases, these changes are unstable, with the acoustic parameters of post-surgical speech gradually reverting toward pre-surgical values, even when this causes speech to become less perceptually or acoustically “normal” (Lee et al, 2002; Niemi et al, 2006). This process might be driven primarily by tactile feedback, which could have differential effects on consonants and vowels, since consonants involve greater contact between articulators; alternatively, it might be driven primarily by auditory feedback, which might be expected to affect consonants and vowels to a similar degree. Previous studies have examined only vowels or consonants in isolation, and they have examined only a single language at a time. Here, a case study of a Korean-English bilingual's speech over the course of a year before and after surgery is presented. The subject's entire phoneme inventory in both languages is examined in order to determine the effects of surgery on different segment types and to determine to what extent the effects are language-specific.