19-07-2011, 03:16 PM
ABSTRACT
Impedance Glottography is noninvasive measurement of the time variation of the degree of contact between the vibrating vocal folds during voice production. The aspect of contact being measured is called the vocal fold contact area (VFCA). To measure VFCA, the device used is called impedance glottograph. The device is also called electroglottograph or laryngograph. The principle of operation of device, the waveform obtained, an algorithm for determination of pitch period is discussed. EGG waveform for various voice qualities, drawbacks in EGG and various noises present are described. Concept of multichannel EGG and applications of electroglottography are discussed.