Auditory-visual and auditory-only perception of phonetic contrasts in children

With the instigation of early hearing detection and intervention comes the pressing need to develop new outcome measures that define auditory-perceptual capacity in young children with hearing loss. We report on one such test: the On-line Imitative Test of Speech Pattern Contrast Perception (On-line IMSPAC). This test assesses the ability of young children to convey phonologically significant contrastive information through the imitation of consonant-vowel monosyllables presented by hearing plus lipreading and by hearing alone. Preliminary data are presented from 30 children assessed on the On-line IMSPAC: 10 children with normal hearing, 10 children with hearing loss ranging from 38.3 dB HL to 100 dB HL (children using hearing aids), and 10 children with profound hearing loss (children using cochlear implants). Their ages ranged from 2.75 years to 7.9 years, with a mean age of 4.9 years. Performance scores were shown to decrease with increasing hearing loss. The children with normal hearing achieved average composite scores (re: chance) of 91 percent for each modality with a negligible effect of age. The children who used hearing aids obtained average composite scores of 72 percent auditory-visually and 69 percent auditory-only with a moderately weak age effect. The children who used cochlear implants averaged 60 percent for auditory-visual presentation and 48 percent for auditory-only presentation; a moderate age effect was evident for the auditory-only presentation. The test was sensitive to differences in the perceptibility among phonetic contrasts. In particular, the vowel contrasts were the easiest to perceive and rear consonant place (in the alveolar-palatal position) was the most difficult. These preliminary results demonstrate the clinical utility of a phonetic-level, imitative test Of auditory capacity for children as young as 2-3 years of age.