Establishing normative threshold data on auditory brainstem response for Sri Lankan children under 5 years of age

Abstract

PURPOSE: This study was designed to gather normative air conduction ABR data in children to establish a physical reference that can be reproduced across clinics in Sri Lanka as normative ABR values for children have not been established. These values can be used as a baseline measurement to diagnose hearing loss among children from infancy to 5 years of age. Objective: To derive normative data using click stimuli for absolute latencies of waves I, III and V and inter-peak latencies of I-III, III-V and I-V and to develop latency-intensity function curves for wave V for six different age groups under 5 years of age. METHODS: This cross sectional descriptive study comprised 258 healthy children of 6 weeks to 5 years randomly selected from the Gampaha district with no previous or present complications/risk factors for hearing loss. ABR was performed to gather data on absolute latencies and inter-peak latencies. Data was analyzed using the SPSS software (1 sample K-S test, paired t test). RESULTS: Mean absolute latency values of wave I, III and V for 6-week old infants and 3 month old children were significantly different (p< 0.05). Inter-peak latencies of wave III-V and I-V for the 6-week old infants were significantly different (p< 0.05). The reasons for prolonged latencies in Sri Lankan children may be attributed to the sensitivity of the ABR instruments and the use of insert earphones instead of headphones. CONCLUSION: The normative ABR data obtained in this study may be used across audiology clinics in Sri Lanka as a baseline measurement to diagnose hearing loss among children from infancy to 5 years of age.