On the production of low tongue tip /s/: a case report.

X-ray motion pictures and electromyography were combined to record tongue movement and tongue muscle activity of a normal speaker during /s/ production. The /s/ was in /i/, /alpha/, and /u/ vowel environments and in two and three consonant clusters. Lead pellets attached to the tongue tip and dorsum were tracked by frame-by-frame analysis of the X-ray film. Recordings from the tongue muscles were graphed and compared with the movement data. Results demonstrate that this subject produces /s/ with the tongue tip down behind the lower incisors and the blade elevated toward the alveolar ridge. EMG data from the tongue shows that the tongue tip depression is not passive but is an active part of the motor strategy used by this subject to elevate the tongue body. These findings suggest that speech pathologists might well include the tip-down strategy of /s/ production in the therapeutic process as an alternative to the tip-up /s/.