Can speech perception be influenced by simultaneous presentation of print?

When a spoken word is masked by noise having the same amplitude envelope, subjects report that they hear the word much more clearly if they see its printed version at the same time. Using signal detection methodology, we investigated whether this subjective impression reflects a change in perceptual sensitivity or in bias. In Experiment 1, speech-plus-noise and noise-only trials were accompanied by matching print, nonmatching (but structurally similar) print, or a neutral visual stimulus. The results revealed a strong bias effect: The matching visual input apparently made the amplitude-modulated masking noise sound more speechlike, but it did not improve the detectability of the speech. However, reaction times for correct detections were reliably shorter in the matching condition, suggesting perhaps subliminal facilitation. The bias and reaction time effects were much smaller when nonwords were substituted for the words, and they were absent when white noise was employed as the masking sound. Thus it seems that subjects automatically detect correspondences between speech amplitude envelopes and printed stimuli, and they do this more efficiently when the printed stimuli are real words. This supports the hypothesis, much discussed in the reading literature, that printed words are immediately translated into an internal representation having speechlike characteristics.