Cognitive Strategies for Monitoring Auditory Signals

Abstract

The discrimination of pitches (pure tones) was tested in three experiments with different arrangements of target and distractor tones in a frequency range of 300 to 800 hertz. Subjects had to identify targets in series of 10 to 28 tones with targets and distractors at random. In the first experiment, either one, two, three, or four different targets were given with only one frequency for the distractor tones placed in the middle of the frequency range. In Exp. 2 an alternating frequency arrangement was used, and in Exp. 3 the distractors were frequencies at the beginning and the end of the tone range. Subjects tended to recode target and distractor tones if more than three individual targets had to be rehearsed simultaneously. However, subjects were able to monitor up to five different pitches if the arrangement suggested the recoding of stimuli to reduce memory load (Exps. 1 and 3) and facilitated auditory discrimination (Exp. 3). If not, subjects' performance deteriorated significantly (Exp. 2).