An acoustic metric for assessing change in vowel production by profoundly hearing-impaired children.

The purpose of this study was to investigate the feasibility of developing an acoustic metric to assess vowel production in profoundly hearing-impaired children. The approach taken was to develop a metric from acoustic analysis of vowel productions and then compare it with the perceptual ratings of the same productions by listeners. Speech samples were collected from three profoundly hearing-impaired children participating in a longitudinal study that investigated the effectiveness of assistive listening devices upon speech development. The metric used the extracted fundamental and first, second, and third formant frequencies to represent the tokens as points in a three-dimensional auditory-perceptual space modeled after earlier work by Miller [J. Acoust. Soc. Am. 85, 2114-2134 (1989)]. Euclidean distances were determined between each point and the intended vowel, which was represented by coordinates taken from the Peterson and Barney [J. Acoust. Soc. Am. 24, 175-184 (1952)] data for children. The data suggest that the three-dimensional metric provides significant correlations between production and perception.