Acoustic characteristics of the /I‐i/ confusion in deaf children's speech

Abstract

The purpose of this paper is to report preliminary data on the acoustic characteristics of error patterns in deaf children's speech. The /I‐i/ confusion was analyzed first because of its high weighting with respect to reduction in percent intelligibility on a multiple linear regression analysis. An acoustical analysis was performed on /i/ in CV syllables which were produced in a sentence context by normal hearing and deaf speakers. Based on the transcriptions of a group of phoneticians, the deaf speakers were then divided into two groups: (1) those who correctly produced the /i/ and (2) those who substituted /I/ for the intended vowel /i/. The data revealed systematic differences in formant values for the three groups of speakers. The two groups of deaf speakers showed the greatest deviation from the normal group in the frequency location of F2. Speakers who produced the /I/ for the /i/ showed the greatest deviation from normal. Measurement of vowel duration revealed no differences between the mean vowel duration for the two groups of deaf speakers, although there were some individual variations. These data indicate that spectral differences associated with the /I‐i/ confusion show a more consistent pattern of deviation from normal than do durational differences. [Research supported by PHS grant 09252 from NINCDS.]