removal of background noise causing distortion of recording

I have managed to remove the background 'hissing using the noise removal application, but it has distorted the background music and the spoken word voice. i have tried reducing the noise 24 and lower. Can you suggest anything. I am not sure what the other tabs do i.e. sensitivity freq. smoothing. thanks Val

The Noise Removal page in the manual is here:

The more noise that you try to remove, the more damage will be caused to the remaining sound. The effect works very well for low level constant noise, but if the noise level is too high then the best that you can expect is a reduction of the noise level and not complete removal. Move the “Noise reduction” slider to the left so that the effect is not trying to remove so much noise.

The quality of the “Noise Profile” is also critical to the effectiveness. If possible select 10 seconds of “noise only” to make the profile.

For voice recordings it can often be beneficial to use the High-pass filter (set to about 80 Hz) to remove low frequency noise before using the Noise Removal effect.

I’ve usually found that when trying to remove FM-hiss or internet carrier hiss that the default settings for Noise Removal work well - provided one can get a good clean bit of the hiss.


If you don’t have a long enough bit of silence to get a good profile, you can “cheat” by importing the track to the second slot, and editing out everything between the gaps in speech/music. If you have multiple recordings from the same day, you can also steal more noisy silence from those clips, and copy/paste them into the second track in audacity. You can them highlight the combined noise profile. Audacity does not care which track you take the profile from, so this works particularly well without modifying your original track.