75610945
Dec 23, 1998
Aug 28, 2001
Electronic conference communication systems, comprising on/off switches, and controls for volume, balance, and adjustment for treble/bass; receivers and transmitters; voting units, namely congress delegate and/or chairman unit for parliamentary, multiple choice or audience response voting; parts and accessories therefor, namely, microphones, headphones, loudspeakers, power supplies, plugs, sockets and cables
Electrical and Scientific Apparatus