User programmable station set bass and treble control

摘要

A user-programmable bass/treble control circuit is embedded within a conventional remotely located codec. A subscriber station set is capable of transmitting out-of-voiceband "control" tones to increase/decrease bass and treble. A tone detector within the codec recognizes and removes these control tones, forwarding them to a programmable equalization filter inserted in the transmit signal path in the codec. The equalization filter will adjust the bass and treble of the to-be-transmitted signal in accordance with these received control tones. Advantageously, the "listener" at the other end will not hear the tones if the tone detector is inserted before the receiver. The user may adjust the tones during the entire conversation and the filter may be "reset" at call completion.