 The first system for creating stereophonic sound (using telephone technology) was demonstrated by Clément Ader in Paris in 1881.The pallophotophone, invented by Charles A. Hoxie and first demonstrated in 1922, recorded optically on 35 mm film, and some versions used a format of as many as twelve tracks in parallel on each strip.The tracks were recorded one at a time in separate passes and were not intended for later mixdown or stereophony; as with later half-track and quarter-track monophonic tape recording, the multiple tracks simply multiplied the maximum recording time possible, greatly reducing cost and bulk.