Language development in hearing-impaired children. Establishment of a reference material for a 'Language test for hearing-impaired children', LATHIC.

OBJECTIVE: In Sweden, there has previously been no normalised test material for the evaluation of language development in individual hearing-impaired children, and for the assessment of various methods of auditory habilitation. The purpose of the present study was to compose, apply and evaluate a test for language development in hearing-impaired children, and to establish the first set of reference values related to age, sex, type and degree of hearing impairment.
METHODS: A test consisting of nine subtests was assembled and developed for, and subsequently applied to, hearing-impaired children in the age range 4-6 years. The inclusion criteria were a pure tone average of 80 dBHL or less and oral language (Swedish) as the first language. Two hundred and eleven hearing-impaired children and 87 normal hearing control children were tested.
RESULTS: The results show that: (1) children with hearing impairment-also unilateral-have a delayed language development; (2) the delay is greater in children with larger losses and tends to decrease with increasing age; (3) 6-year-olds with hearing loss greater than 60 dB have not reached the level of the control group; (4) no difference between right- or left sided deafness with respect to language development was observed; (5) a reference material, applicable during clinical assessment, was established for the most common types of hearing impairment.
CONCLUSIONS: The test designed gave graded measures of important aspects of language development in hearing-impaired children. The results merit further application of the test material.