Question on Effect - Noise reduction

Hello Audacity forum
I was recommended Audacity for cleaning up some audio files.The purpose for using the program is three types of noise removal from audios. All types with one person talking/preaching in a room of 15 m2 with a handful other people.

  1. Audios recorded with a microphone, but noise from stiff fabric in clothes is causing very irritating (closeup “background”) noise.

  2. Audios recorded without a microphone AVR PRO on iPhone quite close to the speaker. The audios lack volume, but relatively little background noise (still some though).

  3. Audios from a little camera. Again; little background noise from people etc., but some kind of quiet “waterfall” noise to it.

I have absolutely no clue about these types of program/editing, and after some Google searches I tried to follow different recommendations/combinations for:
Effect => Noise Reduction (dB) / Sensitivity / Frequency smoothing (bands).

I haven’t really figured out the testing noise profile (samles) other than on the whole audio before choosing the numbers.

Type 1) audio:
The combination 20 / 6 / 3 removes the fabric noise, but then there is some kind of metallic sound it when the voice is of “low volume”.
With a combination 15 / 2 / 6 the irritating fabric noise is still there to some extent, but less metallic sound (I think) to the voice and room sound.

What combination would you suggest to try for this type of audio?

Type 2) and 3) audios:
Do you have any number suggestion for these types?

Thank you for your time and kind regards,
Ingunn Borren

Just a quick-partial response, then I have to get offline…

There are good reasons that pro recordings are still made in soundproof studios with good equipment, good mic placement, and a “good performance”.

The combination 20 / 6 / 3 removes the fabric noise, but then there is some kind of metallic sound it when the voice is of “low volume”.

Yes, noise reduction works best when you have a very-low level, constant, background noise… When you don’t really need it. :frowning:

Any reduction stiffer than about 12-15 is going to cause sound damage.

  1. Noise Reduction is only good with sounds that never change such as air conditioning or computer fan noises. It doesn’t work on occasional sounds such as clothing or other people sounds.
  1. The audios lack volume

That’s easy to fix with Effect > Amplify or Effect > Normalize.

  1. some kind of quiet “waterfall” noise to it

That could be normal microphone noises. Spring Rain in the Trees? Some microphones just do that. It’s rough to design a good microphone and people get paid well for it.

figured out the testing noise profile

That’s pretty serious. Noise Reduction has to identify what you want it to remove with the Profile step. That’s another reason the noise has to be constant and not coming and going.

some kind of metallic sound

That’s normal. Noise Reduction has to rip your sound apart and then try to put it back together without the noise. It gets harder and harder for it to do that as the noise increases.

Noise Reduction used to be called Noise Removal. It was changed because too many people were expecting it to take all the noise out without any damage. Neither tool will do that.

You have a very difficult recording job. I know people who refuse it because there is no “win” at the end.


Hello, thank you for your answer and for taking the time to responding! Kind regards, Ingunn