Subject: getting a signal level from a signal+noise measure? From: Rochelle Newman <rnewman(at)HESP.UMD.EDU> Date: Fri, 3 Sep 2004 16:58:16 -0400Greetings! I've been searching and asking around, but haven't found any positive answers, so I thought I'd try here, as well. Assume one has a recording of a person talking in the midst of background noise; there are also portions of the recording where the background noise occurs without the person talking. Thus, you have the ability to take relative measures of the amplitude levels of the signal+noise combined, and of the noise alone. (I realize these would not be absolute amplitude levels, but they'd be accurate relative to one another.) Is there a mathematical function by which one can estimate the amplitude level of the signal alone (and thus determine signal to noise ratio)? I realize this would never be exact, but is there a formula for mathematically subtracting out the dB level of the noise level and then transforming this in such a way that one can get a rough estimate of the amplitude level of the signal alone? (Or, is there a mathematical function for dB that tells you what level A is at if you know A+B and B alone?) Rochelle Newman -- --------------------------------- Rochelle Newman Assistant Professor Dept. of Hearing & Speech Sciences 0100 Lefrak Hall University of Maryland College Park, MD 20742 (301) 405-4226 Office (Room 0141BB LeFrak) (301) 314-2023 FAX (301) 405-2730 Lab http://www.bsos.umd.edu/hesp/newmanr.html