Pitch of Speech from a Talker Supplied with Various Amounts of Helium

Abstract

A talker is supplied with a breathing mixture from a modified anesthesiology apparatus. The gas contains 20% oxygen, but the remainder consists of nitrogen and helium, the proportions of which may be varied to give several test conditions. In each case, the subject breathes the gas for a sufficient time before talking so that exhalation equilibrium is established. The talker then removes the breathing apparatus, produces a short utterance in a single exhalation, replaces the apparatus, and reestablishes equilibrium, repeating this as many times as may be necessary for the test. The exhaled gas is fed to a tube in which the velocity of sound is continuously monitored by measuring the time that it takes a pulse to travel the known length of the tube. In order to investigate possible acoustical-feedback effects, the subject's hearing is masked by noise for some of the runs. Data on fundamental voicing periodicities in the several cases are presented.