Signal-to-noise ratio of auditory brainstem responses (ABRs) across click rate in the bottlenose dolphin (Tursiops truncatus)
Abstract
Although the maximum length sequence (MLS) and iterative randomized stimulation and averaging (I-RSA) methods allow auditory brainstem response (ABR) measurements at high rates, it is not clear if high rates allow ABRs of a given quality to be measured in less time than conventional (CONV) averaging (i.e., fixed interstimulus intervals) at lower rates. In the present study, ABR signal-to-noise ratio (SNR) was examined in six bottlenose dolphins as a function of measurement time and click rate using CONV averaging at rates of 25 and 100 Hz and the MLS/I-RSA approaches at rates from 100 to 1250 Hz. Residual noise in the averaged ABR was estimated using (1) waveform amplitude following the ABR, (2) waveform amplitude after subtracting two subaverage ABRs (i.e., the “±average”), and (3) amplitude variance at a single time point. Results showed that high stimulus rates can be used to obtain dolphin ABRs with a desired SNR in less time than CONV averaging. Optimal SNRs occurred at rates of 500–750 Hz, but were only a few dB higher than that for CONV averaging at 100 Hz. Nonetheless, a 1-dB improvement in SNR could result in a 25% time savings in reaching criterion SNR.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Feb 01, 2019
- Source ID
- 10.1121/1.5091794
Entities
People
- James J Finneran
- Jason Mulsow
- Robert F. Burkard
Organizations
- National Marine Mammal Foundation
- Naval Information Warfare Systems Command
- U.S. Navy Marine Mammal Program
- United States Navy
- University at Buffalo