Xiv. Speech Communication C C C C C Cc (xiv. Speech Communication)

The first experiment involved the intelligibility of alternated speech. In a typical experiment by Cherry and Taylor, and later by Huggins,2 a continuous speech message was periodically switched alternately to the subject's left and right ears, so that one ear received speech, while the other received silence. The intelligibility was assessed by counting the number of words the subject was able to repeat concurrently a task called "shadowing." The task was quite easy, and shadowing scores were close to 100%, as long as the rate of alternation was either lower than approximately 1 cps, or when the rate was higher than approximately 10 cps. At intermediate rates around 3-5 cps the task was much harder, and shadowing scores dropped to a minimum of 60-70%, although some subjects were much more severely affected. What properties of the situation caused the intelligibility to decline? Clearly, the