Patent ID: 6014441
Filing Date: 2000-01-11
Classification: G06Q,G07F,G10L,H04M,H04Q

Abstract:
A device for generating a series of tone signal pairs, each tone signal pair including simultaneously asserted first and second tones, said device comprising:a first tone generator device generating a plurality of first frequency tones;a second tone generator device generating a plurality of second frequency tones;a first amplifier electrically coupled to said first tone generator device, said first amplifier amplifying a first frequency tone to a first signal level and a first frequency tone to a second signal level;a second amplifier electrically coupled to said second tone generator device, said second amplifier amplifying a second frequency tone to a third signal level and a second frequency tone to a fourth signal level; anda control device in electrical communication with said first and second tone generator devices and in electrical communication with said first and second amplifiers, said control device controlling said first and second tone generator devices and said first and second amplifiers to generate a tone group comprising at least two tone pairs:a first tone pair of said at least two tone pairs comprising said first frequency tone amplified to said first signal level and said second frequency tone amplified to said third signal level; anda second tone pair of said at least two tone pairs comprising said first frequency tone amplified to said second signal level and said second frequency tone amplified to said fourth signal level, said first signal level differing from said third signal level and said second signal level differing from said fourth signal level,wherein said first tone pair is related to the transmission characteristics of a first type of microphone, and said second tone pair is related to the transmission characteristics of a second type of microphone.