Radio Tranmission Static Not Wanted

[jarason]

Hello all. First time posting and first time seeing Audacity. I found it very wonderful. It kind of works for my needs, but not perfect. I know it's my lack of knowledge about these audio things. Here's what problem I have. I have an abundance of audio which is radio communications between cars. I work in the legal community. There is quite a bit of static and feed back on the transmissions. I've learned to eliminate some of the noise, but not all of it. I've only used the "noise reduction" tool, but I'm not sure about how to accomplish other things. I look at the wave lengths and wonder how I take out everything but the actual voice audio. Maybe it's easy and just my lack of knowledge. Can anyone help in a little way. It's an important project. Thanks.

[steve]

Voice is mostly between about 300 Hz and 5 kHz.
You can use the Equalization effect to cut everything above and below this range. http://manual.audacityteam.org/o/man/equalization.html

[polkat]

Also, make sure any microphones, cables, preamp if using one, sound card, and other signal transmission equipment is well shielded.

[jarason]

Thanks guys. Although I've got more to learn, the Equilization did wonders. I hear most of the transmission. There is still some that are bad, but I did here transmissions that the survaillance team was having trouble with their micks. All in all I'm moving forward with the project, all because of your help. Thanks again. (I expect you will hear from me again, at some point.) Hope you all had a nice Thanksgiving.