TONEBURST-EVOKED ABR: NORMS AND GENDER DIFFERENCES

Abstract

Background: The ABR procedure has become a powerful non-invasive technique to assess the integrity of the auditory processing system particularly in infants and difficult-to-test subjects. The inability of click stimulus in frequency selectivity the tone burst makes it possible to obtain relatively narrow frequency range responses, particularly at lower frequencies. However, the click-evoked ABR does not provide frequency-specific information of the auditory system. The lack of normative data and the potential usefulness of the toneburst-evoked ABR, the present study aimed to establish gender-specific norms for the same at the octave frequencies. Methods: Twenty normal hearing subjects within the age range 18 to 25 years were examined followed by tympanometry, puretone audiometry and toneburst ABR for 500Hz, 1000Hz, 2000Hz and 8000Hz in each ear. Results: Wave-V was identified till 20 dBnHL for all tested frequencies with a decrease in mean absolute latency of waves with increase in frequency. Mean absolute latency of each wave was shorter in female than male for the tested frequencies. The difference in mean of puretone and TB-ABR thresholds ranged between 8-11.25 dBnHL for different frequencies. Conclusion: TB-ABR can be reliably used as an excellent tool to achieve frequency-specific information for difficult-to-test population.