Comparison of Levitt- and Zwislocki-type adaptive procedures for stimulus placement in human listeners

Abstract

The "3-down, 1-up" adaptive stimulus placement rules attributed to Levitt and Zwislocki were compared in the context of human interaural time difference discrimination, employing otherwise commonly used procedures (e.g., averaging reversals to estimate threshold). The Zwislocki rule typically accumulated over three more reversals than the Levitt rule but the rules were approximately equally efficient. This may be because the additional reversals did not provide additional information or that any additional information was countered by other factors, such as the lower theoretical asymptotic response probability (0.75 vs 0.794). Relative bias between rules was also explored with the aid of a simulation.