Characterizing Simultaneously Recorded Auditory Brainstem and Middle Latency Responses Using the Parallel Auditory...

The auditory brainstem response (ABR) and middle latency response (MLR) are used to characterize hearing but typically require separate recordings due to differing optimal parameters and setups in clinical systems. The parallel ABR (pABR) paradigm was developed to simultaneously acquire frequency-specific ABRs, but its use of randomized timing sequences also allows for extended analysis windows that can capture both the ABR and MLR in these multi-frequency responses, enabling more comprehensive assessments. We evaluated this simultaneous recording approach by characterizing responses at near- and suprathreshold levels using parameters optimized for pABR. We also provided normative data for the MLRs.

This study used an open dataset on Dryad of pABR recordings from 20 normal hearing adults to tone-pip stimuli at five frequencies, six presentation rates, and two levels. ABR waves (I, III, and V) and MLR waves (P0, Na, Pa, Nb, Pb) were analyzed for presence, latency, and amplitude using linear mixed-effect modeling.

At both levels, ABR wave V and MLR waves Na and Pa were the most consistently identifiable and largest peaks across frequencies, rates, and participants. Frequency and rate changes affected ABR wave V amplitude more than the MLR peaks, whose amplitudes and latencies remained comparatively stable across the moderate and low levels used in this study.

ABR wave V and MLR waves Na and Pa are robust and consistently identifiable with pABR-optimized parameters. A simultaneous recording approach that leverages visualization of all three components could both assess auditory function across more areas of the auditory system using a moderate suprathreshold level, and support detection/interpretation of smaller wave Vs for threshold estimation, particularly for broader low-frequency responses.