Visualization of change of sound characteristics on the level of the vocal cords.

Abstract

The construction is reported of an apparatus for producing short stroboscopic films, employing a new phase-shifting device. This apparatus provides the clinician with a reliable record of the mode of vibration of the vocal cords (in both the opening and closing phases) alongside a tape-recording of the voice. This makes it possible to correlate recordings of the frequency and intensity and transitions of the voice with a series of stroboscopic investigations.