I have two WAV files of the same sound recording, but one contains background noise and the other does not. I am trying to use a bandstop filter to filter the one that contains background noise.
I have found the fft of both signals and graphed them. I have determined two symmetric areas (one with positive frequencies and one with negative frequencies) on the graph of the noisy signal that should be filtered out. The bandstop filter does not use negative frequencies, so I am wondering how I can possibly filter both of these areas out.
Also, how do I find what frequencies these areas on my graphs are?