Two aspects of coarticulation are examined in deaf and normally hearing adolescents: (1) the influence of the final consonant (/t,s,n,d,z/) on the duration of /i/ and /I/, and (2) the influence of initial consonants (/b,d,f/) on theF2frequency of /i/ and /u/. Whereas in normal speech the tense vowel /i/ is only relatively longer than the lax vowel /i/, in the speech of the deaf subjects these two vowels occupy more restricted durational ranges. The vowel does not appear to coarticulate with the final consonant in the normal manner, and thus does not aid in signaling the consonant. In the speech sample examined, initialF2transitions appear “reduced”—both the amount of frequency change and the rate of frequency change are less than for normal subjects. Transitions do not appear to result automatically from the mechanical characteristics of the vocal tract. Results are discussed with reference to the possible role of learning in coarticulation effects. [Supported by NINDS Grant NS03856.]