Optimizing parameters for using the parallel auditory brainstem response (pABR) to quickly estimate hearing thresholds
Timely assessments are critical to providing early intervention and better hearing and spoken language outcomes for children with hearing loss. To facilitate faster diagnostic hearing assessments in infants, we developed the parallel auditory brainstem response (pABR), which presents randomly timed trains of tone pips at five frequencies to each ear simultaneously. We have shown that the pABR yields high-quality waveforms that are similar to the standard, single-frequency serial ABR but in a fraction of the recording time. While well-documented for standard ABRs, it is yet unknown how presentation rate and level interact to affect responses collected in parallel to random tone pip stimuli. Therefore, in this study we determined the optimal range of parameters for the pABR by recording responses across a range of six presentation rates, each at a low and high stimulus level. We show that a wide range of rates yields robust responses in under 15 minutes, but 40 Hz is the optimal singular presentation rate. Extending the analysis window to include later components of the response offers further time-saving advantages for the temporally broader responses to low frequency tone pips. Perceptual thresholds that subtly change across rate allow for a testing paradigm that easily transitions between rates, which may be useful for quickly estimating thresholds for different configurations of hearing loss. These optimized parameters facilitate expediency and effectiveness of the pABR to estimate hearing thresholds in a clinical setting.