2011 Volume 32 Issue 1 Pages 28-33
[Objective] Children with mild and moderate hearing impairment have been identified at a very early stage by the neonatal hearing screening that has been widely performed in recent years. The 80 Hz auditory steady-state response (ASSR) is useful to estimate frequency-specific thresholds in sleeping infants. However, a dissociation between the ASSR and behavioral audiogram is sometimes observed, especially in cases of multiply-handicapped or underdeveloped children.
[Subjects and Methods] Eighty-one children (116 ears) identified as having mild or moderate hearing loss (35–70 dB) using GSI Audera® were investigated in this study. Subjects consisted of 46 boys and 35 girls aged one month to nine years old. The ASSR–threshold was assessed under sedation in all cases. In addition, auditory brainstem response (ABR), otoacoustic emissions (OAE), and behavioral audiograms were obtained depending on the developmental age.
[Results] Of the 81 cases, 33 (39.8%) were referred for appropriate specialized diagnostic intervention by the neonatal screening center. Thirty patients (37.0%) had multiple handicaps. The causes of impaired hearing were otitis media (50 ears, 43.1%), malformation of the middle ear (5 ears), auditory neuropathy (3 ears), and unknown (31 ears). In the remaining 27 ears (19.4%), hearing levels were ultimately determined to be within normal limits after considering findings of other hearing tests. Of these 27 ears, 13 ears (48.1%) were in multiply-handicapped children. In 11 ears (40.7%), ASSR had been performed less than 6 months after birth.
[Conclusion] It was reconfirmed that the hearing level of children with mildly or moderately impaired hearing should be repeatedly assessed not only by ASSR but also by ABR, OAE, and behavioral audiogram.
