Applicability of piezoelectric sensors for speech rehabilitation.

The applicability of piezoelectric sensors for speech rehabilitation was examined by setting vocalizing tasks for seven healthy young adults (four men and three women). A piezoelectric sensor was attached to the front of the neck and each seated subject was instructed to vocalize /a/ with subjective low and high tones and /pa/, /ta/, and /ka/ with a subjective middle tone. The three major findings were: (1) slow potential changes recorded at the start of these tasks were followed by rapid changes; (2) the tasks did not differ in the average range of the slow changes; (3) female subjects had higher average frequencies of rapid changes than male subjects. The frequencies and phases of the rapid changes paralleled the sound waves recorded in the neck during the tasks. Swallowing tasks verified the appropriateness of the recording system. The advantages of using piezoelectric sensors in the clinic are discussed.