Comparison of Stacked Tone-ABR and Chirp ABR in Individual with Normal Hearing and Sensorineural Hearing Loss

Abstract

Background: There are no published studies that compared amplitude of stacked-Tone ABR and Chirp ABR in hearing impaired individuals with sensorineural hearing loss, which need to be investigated. Objective of the study was to know whether amplitude of standard chirp evoked ABR is same as tone burst evoked stacked ABR in individuals with normal hearing listeners and individuals with sensorineural hearing loss. Methods: Present hospital based cross sectional study was carried out at Malla Reddy Institute of Medical Sciences, from January 2016 to December 2016. Two groups of subjects were taken. Group I consisted of 20 ears (14 males and 6 females) with normal hearing. Group II consisted of 20 ears (11 females and 9 males) with cochlear hearing loss. Results: Wave V Amplitude of stacked tone ABR was higher than Chirp stimuli evoked ABR wave V in both the groups. Amplitude of stacked tone ABR and chirp was smaller for individuals with sensorineural hearing loss than normal hearing. Between the 2 chirp stimuli, standard Chirp ABR amplitude was higher than modified Chirp in normal hearing listeners and individual with sensorineural hearing loss. For modified chirp in individuals with normal hearing and cochlear hearing loss. Latency obtained by standard chirp was longer compared to latency obtained by modified chirp, which is seen in both the groups. Conclusions: Chirp ABR may be opted over stacked tone ABR in neurological investigations due to its lesser variability in amplitude and shorter duration of testing.