The auditory brainstem response (ABR): a collection of normative data using the bio-logic AEP system
Links to Fileshttp://library.towson.edu/cdm/ref/collection/etd/id/49227
MetadataShow full item record
Type of Workapplication/pdf
xii, 109 pages
DepartmentTowson University. Department of Audiology, Speech-Language Pathology and Deaf Studies
Auditory brainstem response (ABR) normative data was established for the Bio-logic AEP System based on ABR results from 20 normal hearing, otologically normal individuals between the ages of 20 and 26 years. ABRs were recorded to 100 μs rarefaction click stimuli with a 19.1/sec click rate at intensities 90, 80, and 70 dB nHL for both the left and right ears. Measurements from these recordings included: 1) absolute latencies of waves I, III, and V, 2) interpeak latencies (IPL) of waves I-III, III-V, and I-V, 3) interaural latency differences of wave V and IPL I-V, and 4) wave V/I amplitude ratio. Two additional ABRs were recorded for both the left and right ears; one to a 90 dB nHL condensation click stimulus used to rule out auditory neuropathy spectrum disorder (ANSD), and another to a 90 dB nHL rarefaction click stimulus with an increased click rate (61.1/sec) to observe the effect of click rate on wave V absolute latency . Results revealed mean absolute latency measurements for waves I, III, and V that decreased by approximately 0.2 ms when intensity decreased from 90 to 70 dB nHL. Mean interpeak latencies for waves I-III, III V, and I-V remained stable across the same range of stimulus intensities. Interaural differences between wave V and interpeak latency I-V were less than 0.2 ms, indicating that these measurements were nearly identical between left and right ears. All of the participants had the same ABR waveform polarity in response to a rarefaction and condensation click stimulus. Finally, increasing the click rate from 19.1/sec to 61.1/sec resulted in a mean wave V absolute latency shift of 0.39 ms. All of the measurements obtained in the present study were in agreement with previously reported ABR normative data (Hood, 1998; Beattie, 1988). This equipment-specific data established during the present study will be utilized by students and faculty at the Towson University Hearing and Balance Center when testing patients for retrocochlear pathologies.