Effects of imagining speakers' voices on the retention of words presented visually

Subjects were introduced to one male and one female voice by a tape recording with instructions to attend to characteristics of the voices. Then 18 pairs of words were presented visually on slides. The subject's task during each 10-sec interslide interval was to repeat silently the pair of words over and over again in the male voice, in the female voice, or in the subject's own voice. A surprise recognition test for the words indicated that the words were more likely to be recognized if they were spoken in the same Voice at test as was used to repeat them during presentation. Recognition of the words repeated in the subject's own voice was not affected by the sex of the speaker at test. In Experiment 2, different speakers were used at test than those used by the subjects to repeat the words. The interaction between the sex of voice used at encoding and at test was again significant, but recognition was generally lower than in Experiment 1. It was concluded that it is not necessary to assume that subjects have literal copies of spoken words in memory but speaker's voice does form an integral part of the verbal memory code and its influence is specific to a given speaker as well as to a given class of speakers (male or female).