Peak-to-peak glottal flow amplitude as a function of F(0).

This study investigated the peak-to-peak (p-t-p) amplitude of the voice source as a function of fundamental frequency (F(0)). Nine males and nine females with or without singing training produced (1) a glissando from lowest to highest F(0) and back in their speaking range on /a:/ and (2) an ascending-descending scale pattern on /pa:pa:/. Audio and airflow signals were recorded, the latter picked up from a pneumotach mask. F(0) was measured from the audio signal and the oral pressure during the /p/ occlusion for an estimate of subglottal pressure. Airflow signal was inverse filtered and the p-t-p amplitude was measured for 10 F(0) values, equidistantly spaced along the subject's F(0) range in semitones, thus facilitating comparison between individuals and genders. Most females and males showed both a wide range of relatively large p-t-p amplitude in the speech range and a more or less pronounced p-t-p amplitude maximum, which was located on average at 232 and 162 Hz, respectively. The p-t-p amplitude maximum seems to reflect a complicated interplay between factors that tend to increase and those that tend to decrease the p-t-p amplitude with increasing F(0).