How to remove background television audio from a phone audio recording

Question

Hey guys this is what I am trying to do:

I have audio recordings from my blackberry that have conversations on them. The only trouble is that there is music and tv playing in the background that really makes it hard to hear the voices.

Is it possible to lower or remove or do something to the music/tv sound in the back so the voice comes through louder?

Or who do I take this to to have it done because,full disclosure here, the voice on the recordings is no longer with us, so if anything could be done it would mean the world.

Thanks

Answer 1

Bell Labs once defined noise as "unwanted signal" with that in mind you might want to try the following with your Blackberry recording using a free download known as Audacity. I have used Audacity but not for these purposes so I do not feel completely comfortable offering this as a solution. However, since it's free software, and it should not take too much time to get a result you might give a try:

http://www.makeuseof.com/tag/remove-ambient-noise-audio-files-audacity/

I also found this on Creative Cow:

Re: Keep voice, remove background noise and music by John Murrell on Nov 7, 2011 at 2:57:36 am

You need to combine a number of tools to achieve this. It will probably not be possible to completely serperate the vocal. I use MAGIX Audio Restoration which I use for general audio restoration http://www.magix.com/us/audio-cleaning-lab/. I often use its tools to widen the stereo image, seperate the centre and side channels even further. I then use bx_solo(free) http://www.brainworx-music.de/en/download?PHPSESSID=aeogopu3v7kbu0e0efe495u... or some other tool to ms decode the sound (seperate the mid channel from the stereo). Not a perfect solution.

Answer 2

To start with, you will not be able to do this completely. There will be TV sound, and most likely the voice will sound weird. I will be guiding you in methods to manually do this, but you can find programs that will also partially help.

So the first thing would be to get a compressor and expander (audacity has both, and it's free). First use the expander by increasing the dampening, or attenuation until you hear it actually reducing volume. Then fiddle with the threshold (where the attenuation kicks in) so that it doesn't reduce the volume of the subjects voice. Then you can do sort of the reverse of that to increase ONLY the subjects voice.

(At this point, if I've lost you, then you should go with one of the programs, or look find an audio engineer to do this for you)

Another part is filtering out the TV as much as possible with EQ. First crank the amplitude up all the way, and narrow the Q value (the bandwidth of frequencies effected). Then you can sweep this up and down in frequency. Find where the TV sticks out the most, and then take the amplitude all the way down and widen the Q just a little bit. You might need to find multiple points to do this. You can then do similarly in trying to raise frequencies that strengthen the subjects voice. A High-pass filter might also help, depending on a lot of things.

This may or may not help you, but I hope you get what you're looking for.