Hi, I am trying to extract the residual (noise) from a sound wave. I read up that if you remove ceratin modes (peaks) from the soundwave witch can be detected from the frequency domain. Though sometimes the soundwave wont ahve any obvious peaks or i have got the theory wrong? Has anyone manage to do this or knows how to perform the extraction? thanks

This sort of process is awfully hard, as far as I know. However, the idea is sort of like a feedback reduction ferret, where you attempt to remove the overpowering frequencies in a signal (such as, a 1 khz frequency). However, general "noise" can span many frequencies altogether... even if you're able to reduce the noise in an audio sample, often times you'll destroy much of the signal itself, becoming distorted and less genuine.

There are filters in, say, Sonic Foundry, or other editing tools, but honestly they don't really work that well, if at all (unless I'm stupid). And when you think of government agencies with filtering technology, or whatever you want to call it, are probably getting paid mega bucks to develop private code.

This is similar (but your dilemma is a lot "easier") to the age old question I hear of "How do you take the vocals out of a recording?". Simple answer: you don't, or you go back to the original takes.

Hi,
There is only one way to remove noise from the main sound you want. However it is nearly impossible because you need to find the noise's original wave itself somehow. Well, noise is a waveform, too. If you find the original noise wave (totally same noise in the sound), you can use phase cancellation method. Invert the noise wave 180 degree, and mix with the sound you want to clean. Inverted noise wave will cancel the noise in the sound, so the clean sound will remain itself. This is the theory. It is nearly impossible because it is nearly impossible to find original noise wave as the same as the noise in the sound.

Let's see the second option. You can use noise reduction tools. In that case, you will reduce average level of the sound, and maybe other properties of the sound. It depends on how you use the noise reduction. You can read the articles related to that, plus you can surf on audio mixing and mastering forums.

Best wishes,
Hakan
www.hakanyurdakul.com

Hi,
thanks everyone for the replies.

I will look into some editing tools to help me retrieve the residual noise.

The purpose for gaining the residue of a sound so therefore i can be able to either replace the noise with different sinusoids or mix the residue with sinusoids.

I have already placed a post about adding different sinusoids together and still unsure how to properly do it?

Anyway, Thanks.

Oh i also forgot to mention if anyone knows some good editing tools, please let me know.

Thank you