Signal alternation disrupts perception of music as well as speech

Abstract

Studies over the last 40 years have demonstrated that, when a speech passage is periodically alternated between the right and left ears, intelligibility is disrupted. The perceptual degradation is quite selective: Alternation rates of approximately 3–4 cps are disruptive, while slower or faster rates are not. In addition, the maximally disruptive alternation rate covaries with speech rate: When speech is presented at a faster rate, the critical alternation rate increases proportionally. Models suggested for the phenomenon include attentional limitations, disruption of perceptual units (syllables), and multifactor psychoacoustic theories. A recurring and previously unanswered issue has been whether or not the effect is speech specific, as would be expected if disruption of a unit such as the syllable causes the degradation. To answer this question, a successive same‐different discrimination task was run using piano melodies. On each trial, a monaural melody was followed by a melody that was alternated betw...