Hyperacusis in deaf children who had received cochlear implantation

Abstract

Nine deaf children aged 5-14 years who complained of hyperacusis after receiving cochlear implantation were selected from approximately 80 implanted children treated at our institutions. Characteristics of hyperacusis in these children were compared with those of ten non-implanted children aged 4-12 years, including five normal hearing children and five children with sensorineural hearing loss who complained of hyperacusis. Six of the nine implanted children as well as six of the ten non-implanted children were associated with autism spectrum disorder or Asperger's syndrome. Acoustic stimuli causing hyperacusis in these children were noise produced by a vacuum cleaner, hair dryer or flush toilet, sudden noises produced during construction work, big sounds produced by crowds of people, etc. No differences concerning the types of these causal stimuli were found between the implanted children and the non-implanted children. Although the majority of the implanted children gradually overcame their hyperacusis, one case with autism spectrum disorder and severe mental retardation who had received cochlear implantation at the age of five years began to refuse to use his cochlear implant when he reached 10 years of age. In this particular case, rejection of the cochlear implant was thought to be due to hyperacusis. These findings suggest that hyperacusis in the majority of our implanted children may be attributed to autism spectrum disorder, and in the severest case hyperacusis can cause a child to reject the use of a cochlear implant.