["Specific" versus "audiogenic" speech development disorder. Quantitative speech development index in a controlled group comparison].

The language development of hearing-impaired children is disordered, especially in children with impairment before starting linguistic development. Binaural sensorineural-impaired children are likely to acquire a deficient oral vocabulary. Two population samples between the ages of 2 and 5 years (n = 110 specific language-impaired children vs. n = 34 bilateral sensorineural-impaired children with individual hearing aids) were compared with 66 normal children of similar age with respect to their expressive vocabulary. All groups were tested with a nonverbal intelligence test and reached average or better scores. The two clinical samples showed no significant difference in their lexical performance, but there was a difference in comparison with the normal children. The results are discussed on the background of degree, onset of hearing impairment and attending kindergarten. It is suggested that specific language impairment is a more serve development disorder than audiogenic language impairment because it seems to be neurobiologically founded. Early diagnosis by a phoniatrician is important.