Loop-circuit for telephone line
Loop-start/ground-start line interface circuit
Loopback test starting system
Loud speaking telephone set
Loud-speaking telephone
Loudspeaker apparatus and method for a radio telephone...
Loudspeaker telephone apparatus
Loudspeaker telephone apparatus
Loudspeaker telephone device comprising a novel noise...
Loudspeaker telephone equalization method and equalizer for...
Loudspeaker telephone system
Loudspeaking communication terminal apparatus and method of...
Loudspeaking substation circuit
Loudspeaking teleconferencing circuit
Loudspeaking telephone
Loudspeaking telephone circuit
Loudspeaking telephone instrument
Loudspeaking telephone station circuit
Loudspeaking telephone station including directional microphone
Loudspeaking telephone with a frequency shifting circuit