Glottal Parameters and Some Acoustic Measures in Patients with Laryngeal Pathology.

Abstract

High speed motion pictures of larynges with different pathologies were taken simultaneously with recordings of the acoustic signals picked up by a contact microphone coupled to the neck. The acoustic signals were displayed on an oscilloscope and photographed onto the same film as the laryngeal images. A semi-automated digital reduction system was employed to reduce the acoustic data and glottal dimensions into digital information. The amplitude of the pressure signal and laryngeal parameters such as glottal area, glottal width, and excursion contours of both folds were calculated and displayed by computer programs. A good agreement was observed between the periodicity of the contact microphone signal and that of glottal area, though the phase relation between the two parameters varied considerably from patient to patient. Relations among the glottal area and other laryngeal parameters mentioned above were considered. It is pointed out that the glottal width function does not represent the glottal area function in many cases with pathologic larynges. The validity of the contact microphone technique for extraction of the fundamental periods of speech is discussed in reference to the acoustic approach to detection of laryngeal pathology. [This study was supported by USPHS Grants NS 08177 and NS 08036.]