The Electroglottograph (EGG), Model 6103, is an instrument for investigating the vibratory characteristics of the vocal folds. The non-invasive device provides a waveform representation of vocal fold dynamics and relative contact patterns during phonation.
The EGG transducers, positioned on the surface of the user's neck at the level of the thyroid cartilage, detect changes in impedance across vocal folds during the vibratory cycle. The output of the Electroglottograph is an EGG waveform (also called the Lx waveform) which shows duration, coordination, and relative contact patterns within a glottal cycle. The signal is basically unaffected by other activity in the vocal resonance tract or environmental noise.
The Electroglottograph can be used in conjunction with the KayPENTAX CSL or with KayPENTAX computer-integrated stroboscopy systems (e.g., the Digital Strobe). A software option for CSL (Real-Time EGG Analysis) provides a real-time EGG display, analysis of the waveform for various derived quotients, and fundamental frequency. In the KayPENTAX Digital Strobe system, the EGG waveform can be displayed concurrently with the vibrating vocal folds; the observed video frame of stroboscopic data is time-synchronized to the edge of the displayed EGG waveform.