I. SPEECH PRODUCTION A. GLOTTAL NOISE DURING SPEECH

M. ~ o t h e n b e r ~ * Additive aperiodic components in the voice of one adult male speaker were investigated by using a high pass filter to eliminate most of the periodic components. The glottal volume velocity waveform was r e-corded simultaneously by inverse-filtering the ora l volume velocity. I t was found that for flow ra tes below one liter/second the noise tended to be strongest when the instantaneous glottal volume velocity was a-bout 200 to 300 milliliters/second. When the average glottal a i r flow was increased, a s when the vocal folds were partially abducted for an intervocalic [h 1, another aperiodic component was sometimes noted a t instantaneous flow ra tes above about 1.2 to 1. liter/second. Visual ob-servations using a fiberoptic probe, spectrograms, and measurements of the pressure just above the glottis indicated that this high-flow-rate noise was actually generated in the vocal t rac t above the glottis, and not within the glottis. These patterns in the occurrence of aperiodic com-ponents were used to add filtered gaussian noise to a three-parameter, "black-box " model of the voice source. Results of informal listening tests a r e reported