lucy123 wrote:Hi. When you use the compressor to increase the loudness of a sound, will the quality stay the same? I have a 1 minute sound piece (it's a phone conversation) that I am trying to get louder. But when I make it louder, the static in the background increases and it's much harder to understand what the people are saying. Is this supposed to happen?
Quality is subjective... Depends what you're referring to...
In your case dynamic compression is not useful. Dynamic compression is used when you have very quiet parts and very loud parts and you want to reduce the gap (in volume) between the quieter parts and louder parts. So dynamic compression will make quieter parts louder and louder parts quieter.
Quiet or loud parts have nothing to do with the type of audio you have, doesn't make a distinction between what is noise and what is voice.
So if you have a recording were you have a quiet voice over a loud noise, dynamic compression won't make the noise quieter and the voice louder... If you could do that you would be a very rich man
Computers don't distinguish between noise and voice. So when you amplify and audio signal you will amplify both the noise and the valid audio. So amplifying or using dynamic compression on a recording won't reduce the noise in it while improving the non-noise part of it.
In your case what you can do is to use filters/equalization or noise removal tools. You can filter out certain frequencies. If your recording has only voice, then you know voice only produce frequencies in a certain interval, so you can remove low and high frequencies.
You can also use the noise removal effect in audacity.
On this wiki topic you have some more info about noise removal:
http://wiki.audacityteam.org/wiki/Noise_Removal