sound head

plural sound heads · alternative soundhead

1. A component of a film projector or similar device that reads or writes audio signals in electromagnetic form.

   1 more example

   On the exhibition end, most of the sound heads in use at present slide the film past a stationary sound gate with the result that irregularities in the friction of the film against the gate produce a flutter. As a result of film shrinkage, only one pair of teeth in the pulling sprocket made contact with the film at one time. At the moment the pulling pair of teeth are disengaged from the film a slight slippage of the film is required to bring the next pair of teeth in contact with it. This results in a speed variation known as sprocket-hole modulation. Where a hold-back sprocket is not provided, variations in the tension of the takeup mechanism are transmitted directly to the pulling sprocket with resulting variations in speed.

   1916, Society of Motion Picture and Television Engineers, Journal of the Society of Motion Picture and Television Engineers, page 188