Measurements of glottal structure dynamics.

Low power, radarlike electromagnetic (EM) wave sensors, operating in a homodyne interferometric mode, are being used to measure tissue motions in the human vocal tract during speech. However, when these and similar sensors are used in front of the laryngeal region during voiced speech, there remains an uncertainty regarding the contributions to the sensor signal from vocal fold movements versus those from pressure induced trachea-wall movements. Several signal-source hypotheses are tested by performing experiments with a subject who had undergone tracheostomy, and who still was able to phonate when her stoma was covered (e.