Auditory neuropathy spectrum disorder: a new approach to hearing aid fitting

Abstract

ObjectiveThe aim of this study was to explore the outcome of hearing aid amplification in children with auditory neuropathy spectrum disorder (ANSD) using speech P1 cortical auditory evoked potential (P1-CAEP).Study designForty-five children were divided into three groups: the ANSD group (n=15), the sensorineural hearing loss (SNHL) group (n=15), and the normal hearing group (n=15). The ANSD group had a mean age of 48.2 (±29.4) months and included children with moderate-to-severe hearing loss, a history of bilateral hearing aid use for at least 6 months, and absence of comorbid disorders. The SNHL group was closely matched to the ANSD group. Verification of hearing aids was carried out twice with 6 months of interval and included evaluation of aided sound field and P1-CAEP, and evaluation using the Arabic version of the Infant Toddler Meaningful Auditory Integration Scale (IT-MAIS). The P1-CAEPs were elicited using the temporally modified synthetic ‘ba’ and ‘da’ syllables.ResultsIn the initial evaluation, 80% of ANSD children showed P1 response to the ‘ba’ stimulus and 87% of children to the ‘da’ stimulus. Only one child from the SNHL group did not show P1-CAEP responses to the ‘da’ stimulus. The latency of P1 was prolonged in both groups compared with the normal hearing loss group. At 6-month evaluation, the P1-CAEP latencies improved equally in the ANSD and SNHL groups. Children with absent responses persisted to have absent responses. The mean IT-MAIS scores was initially 45.5 (±20) in the ANSD group and 79 (±9) in the SNHL group and increased after 6 months in both groups. The IT-MAIS scores negatively correlated with the P1-CAEP latency in the two evaluation sessions and positively correlated with the age of hearing aid fitting.ConclusionAround 50% of ANSD children demonstrated benefit from amplification. They showed evidence of normal central auditory maturation and progress in auditory skill development. Longitudinal P1 recording is recommended in the comprehensive audiological test battery in ANSD population using temporally modified speech stimuli.