how to remove background noise from recorded amr files

hello. new to audacity and this site.i have audacity version 2.0.5 on windows vista and have a question. i have cell phone call recordings that i cant hear anything but background noise. the noise sound like static or wind.i can hear the phone ring and hear the person say “hello” on incoming calls then nothing but noise. on outgoing calls all i hear is noise. the conversations are between 30 sec and a few minutes. is there any way to either remove the background noise or isolate the voices in the recordings. any and all help is greatly appreciated.

Sadly, If the noise is that bad, there isn’t much you can do. (The kind of stuff you see in spy movies where they pull a conversation out of the noise at a party, etc., is just science fiction.)

I’m not sure why the recording is worse than the original conversation. You may have some luck with the [u]Graphic Equalizer[/u]. You’ll just have to experiment, moving the sliders up & down to see if you can bring-out the voice frequencies and reduce the noise frequencies. But, there is a LOT of overlap between the voice & noise frequencies in this case.

Audacity has a [u]Noise Removal Filter[/u] where you feed in a Noise Profile (AKA “Noise Fingerprint”) of noise-only, and it trys to filter-out the noise. You are free to try it, but you’ll porbably end-up removing the conversation too… It works best when you have a constant tiny background noise (like a little tape hiss).

Telephone/cellphone recordings are not simple. How are you doing the recordings? Software on the cellphone?

I use an Olympus TP-7 microphone with adapters or TP-8 microphone. That works with any phone and gives a clear recording of both sides in Audacity. The illustration is Windows on the left and a Mac with a StarTech ICUSBAudio adapter on the right.

If you can’t understand the voice, then Audacity will not be able to help you.
iPhone Sound Recorder will not record the far side.