Threshold Pressure for Vocal Fold Collision

A new measurement has been investigated, called the collision threshold pressure (CTP), meaning the minimal pressure required to initiate vocal fold collision. The purpose was to find a measurement that would be more accurate and less time-consuming to collect than the presently used phonation threshold pressure (PTP). Fourteen amateur singers – six female and eight male – were measured using an electroglottograph (EGG) and a pressure transducer that the subjects held in the corner of their mouths. The EGG showed if the vocal folds collide. All subjects were measured at several pitches before and after vocal warm-up. Both CTP and PTP tended to be higher before vocal warm-up. In addition, the differences varied greatly both within and between subjects. A clear result was that the CTP analysis demanded less time than the PTP analysis. The standard deviation of the PTP values collected here were smaller than those published in a previous investigation. Moreover, the standard deviations for CTP and PTP were compared in two subjects and were found to be lower for CTP. Thus, CTP may be a more useful measurement of vocal fold characteristics than PTP.