Evaluation of glottal inverse filtering by means of physiological registrations

Over the years a number of inverse filtering methods for recovering the volume flow at the glottis from the acoustic speech signal have been designed. Formal tests of these methods have, however, been the exception rather than the rule. We describe an attempt to use registrations of the electroglottogram, photo-electroglottogram and the subglottal pressure, recorded at the same time as the speech signals, to establish the instants of opening, closing and maximal width of the glottis. Although the determination of those epochs from the registrations proved to be less straighforward than anticipated we have succeeded in showing their usefulness for evaluating the accuracy of flow pulses reconstructed by means of inverse filtering techniques.