Aerodynamic measurements of voice production

This article reviews measurement techniques, normative results and clinical uses of the aerodynamic voice measures maximum phonation time (MPT), vital capacity (VC) and phonation quotient (PQ). Variations in measurement procedures have proven to yield different results. Simple test techniques have resulted in the following normative data: 22.2 sec for MPT, 4800 ml for VC, 269 ml/sec for PQ in adult men, and 18.4 sec for MPT, 3500 ml for VC and 233 ml/sec for PQ in adult women. None of the three parameters can be used to diagnose voice disorders, but each of them is useful for evaluating their degree and for monitoring their evolution. MPT appears to be the most sensitive measure of the three.