CONSISTENCY OF AUDITORY DETECTION JUDGMENTS.

An observer's decision in a psychoacoustic detection experiment is governed by two broad classes of determinants: (1) external determinants, such as the likelihood of a particular waveform being a signal in noise, and (2) internal determinants, the momentary state of the observer's nervous system, his response biases, or biases as to certain sequences of responses. The aim of the study was to determine, via a measure of the observer's consistency, the relative contribution of these factors. To achieve this end, the audio information presented during a sequence of two‐alternative forced‐choice trials was taped and repeated to the observer at a later time. The consistency of the observer's judgments was measured by determining a percent agreement score: the percent of times the subject agreed with his previous response on those special trials of the sequence in which no signal occurred on either interval of the forced‐choice trial. Percent agreements range between 80% and 55%, depending on the observer and,...