Uncertain-frequency detection: Cuing and condition of observation

Two experiments are described which support a two-factor model of the detection of signals of uncertain frequency. This model asserts that both the number of channels to be monitored (M) and the accuracy (or bandwidth, W) of that monitoring influence detection. The condition of observation, whether simultaneous or successive, was also varied within this paradigm. Stimuli consisted of tones presented with a background of filtered noise. A yes-no psychophysical procedure was employed. In Experiment 1, tonal cues were used to reduce uncertainty about W while holding M constant. This resulted in improved performance. In Experiment 2, the validity of the tonal cue was varied. Good cues improved performance, while bad cues harmed it. This latter finding suggested that reducing uncertainty about one possible signal increased uncertainty about the other.