Prosodic disturbance in aphasia: speech timing versus intonation production.

Temporal control has often been suspected to be a critical factor in intonation production. In particular, disturbance in the production of fundamental frequency (F0) associated with intonation in patients with aphasia has been attributed to a primary underlying deficit in speech timing. The present study examined the speech timing abilities of two groups of patients with fluent and nonfluent aphasia who were found in a companion study to have relatively normal intonation production ability. Results indicated severe temporal control abnormalities for the patients with nonfluent aphasia. The fluent aphasic patients performed at comparable levels with the normal subjects, although in absolute terms their durations were also generally longer than normal. These findings do not support the view that intonation production depends critically on speech timing, and that its disturbance in aphasia is due to underlying temporal control deficit.