AP and ABR tuning curves: A comparative study

Abstract

Whole‐nerve action potential (AP) and auditory brain‐stem response (ABR) were recorded from anesthetized eats. Response amplitude and latency to a probe stimulus were measured and tuning curves were constructed using three masking paradigms; forward, simultaneous (a tone burst masker overlapping the probe), and continuous (a continuous masker tone). AP and ABR tuning curves were generated on the basis of criterion changes in both amplitude and latency of the response. Within each of the masking techniques, tuning curves developed from the amplitude and latency criterion changes of the AP and the ABR showed no significant differences. The only significant differences were measured across masking conditions. Forward masking tuning curves were found to have steeper high‐frequency slopes, higher Q 10 values, and lower sensitivity indicies (defined as the difference between probe level and the level at the tip of the tuning curve). Low‐frequency slopes and the tip‐to‐tail ratios showed no significant differences. [Work supported partially by the Deafness Research Foundation.]