Some Aspects of Model Larynx Function
Raymond T. Carhart · The Journal of the Acoustical Society of America · 1942
During the past six years an intensive study of the cushion-pipe variety of model larynx has been carried on in the Speech Laboratory at Northwestern University. The rationale for this research is that it allows conditions to be controlled and factors to be isolated in a manner impossible with the living speech mechanism. To the degree that it is a good analogy, the model larynx gives insight into the physical behavior of the human mechanism. Specifically, the following are among the experimental findings whose implications are challenging. First, the adjustment of the supply-tube exerts a critical influence on the frequency and amplitude of cushion-pipe vibration. Second, the mode of vibration is complex, being a combination of horizontal and vertical components. The pattern of vibration is affected by supply-tube adjustment. Third, the mechanism of sound initiation within the model larynx is of the puff tone variety rather than of the vortex tone variety. Fourth, the acoustic spectra of sounds emitted by the model larynx are of three kinds: harmonic, predominantly harmonic, and predominantly inharmonic.