Highly redundant messages were recorded at normal and fast rates of talking. Certain words were gated out of these messages and listening tests were performed on these words. Nonredundant messages were then recorded using these same words in similar phonetic environments. The same words were again gated out and listening tests were again performed. Quite apart from these listening teats, two operational measures of redundancy were derived. One measure was based on a finite-state model of perception and readers were asked to guess what word n would be after they had read all the words through word n − 1 in a sentence. The second measure was based on the hypothesis that people reserve their final decision on the recognition of each word until they perceive an entire sentence. Readers read an entire sentence in the midst of which a word was represented by a dash. They were then asked to guess what the missing word was. Our index of redundancy was the percent of correct guesses. The results of our listening tests show that the intelligibility of the gated words is inversely proportional to the redundancy index obtained by the second measure of redundancy.