Evidence for auditory signal-detection templates tuned to both the frequency and duration of an expected signal

Abstract

When trying to detect a tonal signal in a continuous broadband noise, listeners attend selectively to both the frequency and the duration of the expected signal. However, it is not known whether they monitor separate, or combined, representations of these two attributes. To investigate this question, a probe-signal method was used to measure the detectability of signals of expected and unexpected durations at two expected frequencies. Four listeners were led to expect one of two signals to be presented at random: a brief tone at one frequency or a long tone at another frequency. For each signal frequency, the detectability of the signals of unexpected duration decreased to near chance as the difference between the expected and unexpected duration, at that frequency, increased. Thus, signals of each expected duration were rarely detected when they were presented at a frequency not associated with that duration. The frequency specificity of this duration tuning indicates that both the frequency and the duration of an expected stimulus are represented in a single signal-detection template. [Work supported by NIH.]