Effect of number of masking talkers and auditory priming on informational masking in speech recognition.

Three experiments investigated factors that influence the creation of and release from informational masking in speech recognition. The target stimuli were nonsense sentences spoken by a female talker. In experiment 1 the masker was a mixture of three, four, six, or ten female talkers, all reciting similar nonsense sentences. Listeners' recognition performance was measured with both target and masker presented from a front loudspeaker (F-F) or with a masker presented from two loudspeakers, with the right leading the front by 4 ms (F-RF). In the latter condition the target and masker appear to be from different locations. This aids recognition performance for one- and two-talker maskers, but not for noise. As the number of masking talkers increased to ten, the improvement in the F-RF condition diminished, but did not disappear. The second experiment investigated whether hearing a preview (prime) of the target sentence before it was presented in masking improved recognition for the last key word, which was not included in the prime. Marked improvements occurred only for the F-F condition with two-talker masking, not for continuous noise or F-RF two-talker masking. The third experiment found that the benefit of priming in the F-F condition was maintained if the prime sentence was spoken by a different talker or even if it was printed and read silently. These results suggest that informational masking can be overcome by factors that improve listeners' auditory attention toward the target.