Phonetic inventory development in young cochlear implant users 6 years postoperation

Increases in the phonetic inventories of a group of 9 children in the Fifth and sixth years of experience with a cochlear implant are reported, extend ing a previous 4-year study (T. A. Serry & P J. Blamey, 1999). Thirty-six o ut of 44 phones in Australian English reached the criterion of 50% correct in the conversational samples of 5 or more children. This level of performa nce corresponds to intelligible, but not completely natural, speech. The ra te of improvement in the sixth year was slow, indicating a probable plateau in performance. The 8 phones that did not attain the 50% criterion in 5 or more children were wl/(sic)/. Potential reasons For the slow development o r nondevelopment of these phones include very low Frequency of occurrence f or /(sic)/ and the perceptual and articulatory characteristics of /(sic)/. /t/ is also subject to a high degree of allophonic variation in the fluent speech of normally hearing speakers, probably accounting for much of the va riability in its articulation in the conversational samples.