1989 Volume 30 Issue 1 Pages 5-10
The vocal efficiency is defined as the ratio of acoustic power (output) to aerodynamic power (input) . It is, however, impractical to use vocal efficiency as an indicator of the pathological voice because of the difficulty in measuring aerodynamic power. As a result, several substitutional indices of vocal efficiency have been proposed, such as the AC/DC ratio of the volume velocity, the ratio of SPL to DC flow, and so on. The purpose of this paper is to investigate the validity of these indices by computer simulation.
Among these indices, the AC/DC ratio and SPL-20*log10 (DC/10) proved to be reliable for evaluating efficiency not only in normal but also in pathological phonations.
