Effects of background music on phonological short-term memory

Immediate memory for visually presented verbal material is disrupted by concurrent speech, even when the speech is unattended and in a foreign language. Unattended noise does not produce a reliable decrement. These results have been interpreted in terms of a phonological short-term store that excludes non-speechlike sounds. The characteristics of this exclusion process were explored by studying the effects of music on the serial recall of sequences of nine digits presented visually. Experiment 1 compared the effects of unattended vocal or instrumental music with quiet and showed that both types of music disrupted STM performance, with vocal music being more disruptive than instrumental music. Experiment 2 attempted to replicate this result using more highly trained subjects. Vocal music caused significantly more disruption than instrumental music, which was not significantly worse than the silent control condition. Experiment 3 compared instrumental music with unattended speech and with noise modulated in amplitude, the degree of modulation being the same as in speech. The results showed that the noise condition did not differ from silence; both of these proved less disruptive than instrumental music, which was in turn less disruptive than the unattended speech condition. Theoretical interpretation of these results and their potential practical implications for the disruption of cognitive performance by background music are discussed.