Telephonic communications – Substation or terminal circuitry – For loudspeaking terminal
Patent
1992-09-09
1994-10-25
Dwyer, James L.
Telephonic communications
Substation or terminal circuitry
For loudspeaking terminal
379388, 379389, H04M 908
Patent
active
053596536
ABSTRACT:
A circuit arrangement for dynamic control of a voice terminal apparatus contains a compander function. Instead of analog circuits for dynamic expander and compressor, a digital signal processor (DSP) is employed which, via a prestored characteristic (KL), assigns to individual average level values of the input signal, amplification factors which are fed to the amplifier (VS) located in the send path of the terminal apparatus. The stored characteristic can be shifted or replaced by another characteristic as a function of a noise average value, or from a receive average value obtained from the audible feedback signal. Thus, an amplification change in the send path is compensated in its action upon the audible feedback signal arriving via the receive path. In a further development, the circuits delivering the level average values are replaced by the digital signal processor, which carries out the functions assigned to these circuits by means of subprograms.
REFERENCES:
patent: 4513177 (1985-04-01), Nishino et al.
patent: 4560840 (1985-12-01), Hansen
patent: 4571461 (1986-02-01), Uno et al.
patent: 4700382 (1987-10-01), Means et al.
patent: 4891837 (1990-01-01), Walker et al.
patent: 4912758 (1990-03-01), Arbel
patent: 4965822 (1990-10-01), Williams
patent: 4982427 (1991-01-01), Nicolai
patent: 5075687 (1991-12-01), Chen et al.
patent: 5199065 (1993-03-01), von Zitzewitz et al.
patent: 5255316 (1993-10-01), Poirier et al.
W. Kraft, "Talking Without Your Hands: How Digital Handsfree Equipment Works and Some Examples of Its Use", Telecom Report, vol. 12, No. 3 Jul./Aug. 1989, pp. 131-135.
Heitkamper Peter
Walker Michael
ALCATEL N.V.
Dwyer James L.
Weaver Scott L.
LandOfFree
Circuit arrangement for controlling the volume range of a voice does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Circuit arrangement for controlling the volume range of a voice , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Circuit arrangement for controlling the volume range of a voice will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-141513