Measurement of stapedius contraction during vocalization effort in patients after laryngectomy or tracheostomy.

The contraction of the stapedius muscle during the effort of vocalization was examined by measurement of acoustic compliance in subjects who had undergone laryngectomy or tracheostomy. No significant level of persistent compliance change was recorded in any of the subjects, indicating the absence of effective contraction of the stapedius during the vocalization effort. In two subjects who use an electrolarynx, although no significant compliance change resulted from the simple vocalization effort without the electrolarynx (no actual vocalized sound), a remarkable level of persistent compliance change was observed during the vocalization using the electrolarynx. These results seem to indicate that a simple vocalization effort without actual voice cannot elicit effective contraction of the middle ear muscles, and that sound generation during vocalization is essential for effective contraction of the middle ear muscles during vocalization, at least in some human subjects.