The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 04, 1999
Filed:
May. 09, 1996
Michael Walker, Baltmannsweiler, DE;
Alcatel N.V., , NL;
Abstract
With hands-free communication methods for stereophonic hands-free communication to transmit room acoustics, and with multichannel hands-free communication to reproduce different speaker locations at a conference table, the acoustical couplings between loudspeakers and microphones located in the room must especially be taken into consideration, in addition to the influence of ambient noise and the control of duplex communication situations. The n.sub.2 couplings take place in n-channel transmission systems. According to the invention, for each coupling, a coupling factor (dlm) is formed from the quotient of a short-term average value of the transmitted signal (ysam) assigned to a microphone, and the short-term average value of the received signal (xsam) assigned to a loudspeaker. With the coupling factor (dlm) weighted with the short-term average value (xsam), the transmission curve of a compander (1.1, 1.2) is automatically and briefly shifted in a way, so that ambient noise and echoes are suppressed in each transmission channel, and only the speech signal is transmitted.