PAMR: An Objective Tool to Measure Hearing Sensitivity in Individuals with Normal Hearing and Hearing Impairment

Abstract

The present study was aimed to find the percentage of occurrence of post auricular muscle response (PAMR) in individuals with normal hearing and to estimate the hearing threshold in hearing impairment. The individuals with hearing impairment were divided into two groups. One group with individuals having sensorineural hearing loss and the other group with individuals having auditory neuropathy. PAMR was used to estimate the hearing threshold by using the protocol given by Purdy et al. (2005). The results showed that, for individuals with normal hearing the presence of PAMR at 80 dBnHL was 100% and above 90 % at 20 dBnHL for both males and females. No gender effect and ear effect was found for latency measures in individuals with normal hearing. In individuals with sensorineural hearing loss, the PAMR thresholds were significantly correlated with the puretone averages (PTA1 & PTA2). No ear effect was seen in individuals with sensorineural hearing loss. Hence, the PAMR can be used to estimate the hearing threshold in individuals for whom ABR cannot be done due to increased muscle tension and also for difficult to test population. The results also showed that the PAMR was not an effective tool to measure the hearing sensitivity in individuals with auditory neuropathy as most of the individuals in this group did not have a recordable PAMR