Detection theory and psychophysics

Abstract

Part I: Traditional psychophysical models and Tanner and Swets ' model are criti-cally examined. Some of the weaknesses of these models are found to be eliminable by a more sophisticated analysis in terms of detection theory. Accordingly, psychophysical methods are re-examined, and the two-category forced-choice technique is found to be particularly advantageous on theoretical grounds. Application of detection theory to the problem of auditory masking with gaussian noise as measured by this forced-choice technique leads to the mathematical derivation of the theoretical ("ideal detector") psychophysical function for this situation. Part II: Experiments using the forced-choice method with auditory signals masked by broadband gaussian noise are reported. The aim of these experiments is to deter-mine the extent to which and the manner in which subjects differ from the "ideal detec-tor " of detection theory. It is found that, except for being approximately 13 db less sensitive, subjects behave very much like the ideal detector- that is, in accordance with the mathematical predictions of Part I- when the signals are pure tones. Results