There is evidence that infants are able to manipulate cues to word stress as early as babbles. For children with cochlear implants (CI), word stress production may pose difficulties since the CI does not provide enough detail for adequate perception of f0 or intensity changes. This study is a longitudinal investigation of pitch, intensity and duration in disyllabic babbles and first words by normally hearing (NH) and children with CI. Both groups had smaller acoustic differences on babbles than on words, and children with CI made smaller differences in pitch and intensity than the NH g r o u p. A m a r k e d i n c r e a s e i n a c o u s t i c differentiation was seen in the NH group on words, especially for pitch. Although there was a trend in the same direction in the CI group, the same shift was not observed in their lexical productions. Implications for language processing in this population and theories of language acquisition are considered.