Abstract
The electroglottogram (EGG) has been used to measure details of vocal fold vibratory cycles for more than two decades. EGG offers advantages not only for research but also in clinical situations, as it is the most non-invasive technique for subjects and can be performed relatively easily, without requiring any expensive apparatus. It is not uncommon in Europe and the United States for EGG to be used in the clinic for routine examinations of pathological vibrations of the vocal fold.
This article covers a variety of aspects relating to EGG including the basic operating principles, the apparatus arrangement, what the EGG waveform actually represents, the validity of the wavef orm, and interpretation of the idiealized wavef orm. In addition, the usefulness of EGG as a technique to measure vibratory cycles both for physiological and pathological vocal folds, objective and visible recordings and biofeedback in voice therapy are described.
