Verbal IQ Scores of Hearing-Impaired Subjects Trained by Kanazawa Method —Subjects with normal range performance—

Abstract

  We administered the Wechsler intelligence scales to 18 hearing-impaired children/adults aged ≥9 years with normal range performance intelligence (PIQ) levels who had received language training using the Kanazawa method from infancy until entering primary school and evaluated items that may affect verbal intelligence (VIQ). The VIQ scores ranged from 60–124, and the median was 92. Fourteen of 18 (77.7%) subjects were within normal VIQ range, and 16 of 18(88.9%) were administered the test orally. Evaluation of items that may affect the VIQ score (training initiation age, hearing level, or PIQ score) revealed no significant influence of any item, but speech intelligibility significant influenced the VIQ score. For hearing-impaired children to acquire normal speech, it is not necessary to have a high PIQ. We consider that the Kanazawa method using visual language forms such as written language and sign language during infancy may promote the development of verbal intelligence in hearing-impaired children/adults.