Help Please - Cleaning up Interviews

Hello everyone. I apologize in advance if this is out of line. I am a researcher who is publishing a book later this year on the perpetration of genocide. In researching the book I did quite a few interviews with perpetrators and victims of genocdie in Rwanda, Bosnia, and elsewhere. I have around 6 interviews (one in Rwanda and five in Bosnia) that are too garbled to be used. There is quite a bit of background noise but the voices of the interviewees also sound somewhat distorted. I have a feeling that they are not beyond redemption (in spite of being wav files recorded on a basic audio recorder in 2009) but my very limited skills in audacity are not up to the task.

I’m wondering if there is anyone on here who could have a look at these few interview files to see if they can clean them up (just through the audacity tools)? I cannot attach the files here as they are anonymous (to protect the interview subjects). I would greatly appreciate assistance and would, of course, also acknowledge your help in my book. Thank you!


Kjell Anderson

I have around 6 interviews (one in Rwanda and five in Bosnia) that are too garbled to be used.

Are you saying that you can’t understand what’s being said?

The human brain is usually the best filter, and if you can’t make-out what’s being said with careful-repeated listening, I don’t have a lot of hope… But, you can try some filtering/equalization. Filtering-out frequencies below ~200Hz and above -5kHz can reduce high & low frequency noises without much affect on speech. The main voice frequencies are around 200-400Hz, so you can try boosting those a little, and boosting above ~4kHz can bring-out the “T” & “S” sounds to help with intelligibility. (If you’re going to boost the “T” & “S” sounds, then you may not want to filter-out the sounds above 5KHz, it depends on whatever works best for your recording.)

But… Voice and most real-world sounds cover most of the same wide frequency spectrum and there is lots of overlap so you can’t really isolate the voice from other sounds.

…Pros still record in soundproof studios with good equipment and good mic placement. On-location movie dialog is re-recorded I the studio. …Even with the best pro software, there is only so-much that can be done to fix-up a bad recording.

Audacity can’t separate voices, music and sounds from each other so you can work on some without the others.

That and once you have trouble understanding words, you’re not cleaning up any more. That’s Disaster Recovery and Audacity doesn’t do so well with that.


Hello DVD doug and Kozikowski and thanks very much for your responses. You can understand some of what is being said but sometimes it is quite faint. There is also quite a bit of ambient background noise. I think this goes beyond noise that was in the actual environment when I recorded and is really a kind of distortion. I feel like I can almost understand but not quite.