Lip Vibrations in a Cornet Mouthpiece

High speed photographs of a cornet player's lips were made in rapid succession to obtain a record of the separation of the lips as a function of time, and of the shape and size of the orifice at different fundamental frequencies. Pictures were taken not only along the axis of the mouthpiece, but at right angles to it, to permit observation of the extent of lip vibration along the axis. A mouthpiece is used which is specially constructed with a Lucite rim and window. Lip separations of as much as 2.8 mm at low frequencies and axial amplitudes of 1 mm are observed. The phase at which maximum separation occurs, taking zero phase at the point of zero separation, is seen to shift in going from the lowest to the highest notes played. Fourier analyses of the separation‐time curves are made by the Runge method, to obtain amplitude values for the first five harmonic components. The area of the opening is obtained as a function of the lip separation, enabling one to plot area‐time curves.