2017 Volume 60 Issue 1 Pages 43-52
The aim of this study was to determine the age, in months, of conditioning in for visual reinforcement audiometry (VRA) in hearing-impaired infants, including the effects of the hearing levels and motor development. The subjects were 20 hearing-impaired infants who were diagnosed as having hearing impairment immediately after newborn hearing screening and received hearing aids under 6 months of age. The estimated hearing loss in each infant ranged from moderate to profound in the better ear. VRA was carried out to assess the minimum response levels (MRLs) across frequencies using 3A insert earphones and a bone oscillator with warble-tone stimuli generated from an audiometer. The ages of shaping a conditioning were distributed from 6 to 11 months in 19 infants (95%), except for the one infant with Down's syndrome. The correlation coefficient between the VRA MRLs at 2000Hz and ABR thresholds were high (r = 0.87), furthermore the difference of both means was close to 0.5dB (1SD=±9.6dB). A significant relation was found between the months of shape of conditioning and the averages of the MRLs (r = 0.58), whereas retardation of motor development (holding up head, sitting and toddling by themselves) had no significant effect. The findings indicated that a the cross-check assessment with VRA after 1 year of age could contribute to early amplification and aural habilitation.
