Children and adults participated in two speech perception experiments in which they listened to recorded consonant-vowel-consonant (CVC) words in random order and resPonded by indicating which number of a word-pair they had heard. Some but not all stimuli that were intended to induce perceptual cross-over were successful in getting subjects to change the voicing category of their responses. Both vowel duration and subject age were found to significantly affect judgments about final obstruent voicing. Children showed perceptual cross-overs later in the duration continuum. These results are consistent with previous research. One result that remains to be explained, however, is the failure of the three-year-olds to shift their responses according to variations in vowel duration. The task may have been too difficult, or vowel duration differences in isolation may not have been sufficient cues to the final voicing contrast. The research is viewed as an inconclusive contribution to the issue of whether production or perception takes precedence. (Author/JB)