A simulated part of the human vocal tract above the glottis is formed as a
resiliently flexible, cylindrical tube with a wall of sponge/foam
saturated with water and covered by a thin, flexible water retaining
skin. The wall can also be a gel or skin balloon filled with water or
oil. A speech simulator has a buzz generator formed by an air compressor,
accumulator and regulator supplying air to an chamber filled with sound
absorbing batting and having a tubular outlet connected to an inlet end
of the tube and covered by a valve simulating a glottis and vocal chords
and formed by a rubber membrane slit to provide two flaps controlled by
respective pen motors. the tube can be constricted manually to provide
various animal and human vocal sounds.