Abstract:
The one-up one-down adaptive (staircase or up-down) procedure is often used to estimate the speech recognition
threshold (SRT) in speech-in-noise testing. This article provides a brief historical overview of the one-up one-down
procedure in psychophysics, discussing the groundbreaking early work that is still relevant to clinical audiology and
scientific research. Next, this article focuses on two aspects of the one-up one-down adaptive procedure: first, the
standard error of measurement (SEM) and, second, the fluctuations in the track [i.e., the standard deviation of the
signal-to-noise ratios of the stimuli within the track (SDtrack)]. Simulations of ideal and non-ideal listeners and experimental
data are used to determine and evaluate different relationships between the parameters slope of the speech
recognition function, SRT, SEM, and SDtrack. Hearing loss and non-ideal behavior (inattentiveness, fatigue, and giving
up when the task becomes too difficult) slightly increase the average value of SDtrack. SDtrack, however, poorly
discriminates between reliable and unreliable SRT estimates.
