Abstract
The speech recognition ability in children with unilateral hearing loss is similar to that in age-matched children with normal hearing in quiet and slightly noisy environments. However, in noisy environments, such as in working classrooms, children with unilateral hearing loss show reduced hearing ability as compared to children with normal hearing. An FM system, consisting of a microphone worn by the teacher and a receiver fitted in the normal ear of students with unilateral hearing impairment, is used in school classrooms. The FM receiver fitted into the normal hearing ear was shown to improve the speech recognition ability of children with unilateral hearing loss in noisy environments. Use of the FM system is recommended as an audiological management tool to overcome the listening difficulties of children with unilateral hearing loss in noisy school classrooms.
In the past, it was believed that unilateral hearing loss has a minimal impact on the speech and language development in children. However, several studies have suggested that some school-age children with unilateral hearing loss show language learning impairments. We found that the development of receptive vocabulary and verbal intelligence, but not that of performance intelligence, was delayed in more than a half of preschool-age children with unilateral hearing loss. However, children with unilateral hearing loss who showed delayed language development in preschool age often caught up with the children with normal hearing in terms of vocabulary and verbal intelligence after school admission. Future investigations are warranted to explore what kinds of auditory amplification or educational assistance may be effective to compensate for the delay in language development in children with unilateral hearing loss.
