An encyclopedia about voice, swallowing, airway, coughing, & other head + neck disorders.

This terminology is used widely to refer to machine-made measures of acoustic, aerodynamic, and electroglottographic output of the voice. At our practice we use quotes around the term objective because, for several basic reasons, these measures are not as objective as they are given credit for. First, the result of such measures may vary markedly with seemingly small changes in voice production, within the same voice. Second, the measures may be entirely non-specific to any particular diagnosis or condition. In other words, one might have the same or highly similar jitter, shimmer, and aerodynamic measures for any one of several completely different diagnoses, e.g., vocal cord cancer, vocal cord paralysis, vocal cord bowing, nonorganic voice disorder, and so forth.