Noise effects on rehearsal rate in short term serial order memory

Three experiments are reported which were designed to test the hypothesis that the rate of rehearsal during noise is slower than that under quiet conditions. The first experiment measured directly the rate of articulation while subjects either read or rehearsed a set of five consonants. It was shown that while the rate of articulation when reading aloud did not differ under the two noise levels [65 dB(C) and 85 dB(C)], rate of articulation during overt rehearsal in loud noise was significantly slower than under quiet conditions. In Experiment II a similar effect was demonstrated where words were required to be read or rehearsed; here it was shown that the greatest impairment due to noise was on the rate of rehearsal of words of long spoken length.

The third experiment showed that loud noise impaired recall performance more markedly for a set of words of long spoken length presented early on in the sequence than for a set of shorter words, even though both sets were equal in the number of syllables and phonemes they contained.

It was concluded that in verbal memory tasks where rote rehearsal of the to-be-remembered material is the predominant strategy for enhancing trace duration, noise may affect memory performance by slowing down the rehearsal rate.