DICTAPHONE

SOUND RECORDING AND REPRODUCING APPARATUS USING SOUND RECORDS HAVING SIGNAL TRACKS IN THE FORM OF GROOVES, MAGNETIZED PARTICLES, OR THE LIKE, AND INCLUDING OFFICE DICTATING MACHINES, [ CONFERENCE RECORDING MACHINES, ] TRANSCRIBING AND PLAYBACK MACHINES, PARTS THEREOF AND AUXILIARY EQUIPMENT THEREFOR INCLUDING MICROPHONES, LOUDSPEAKERS, EARPHONES, [ ELECTRIC MOTORS, SOUND RECORDS, CONTROL SWITCHES, AMPLIFIERS, ] AND THE LIKE