What PC software to use to remove noise from a radio recording?

March 31, 2005 1:33 PM

I record several NPR radio programs with my RadioSHARK and am happy with the process except for the vague background noise. What can I use to filter out the noise without the sizable investment in MY time?

I've used Audigy with great success as far as a result, however the load time for a 60 minute audio file is subtantial, then I have to find a section of silence to sample the hiss, then apply noise reduction to the entire thing, then save it.

Even though the human intervention time on this isn't big it takes a lot of my time to do this to the 4 programs I record currently and possibly more down the road.

I'd like something I can feed the files to which will scan the entire thing, make a 'best guess' about the noise waveform and then remove it and save the result. It can take almost any amount of time so long as I can fire it off for multiple files and walk away.

It needs to run on an Intel/Windows machine since that's where the RadioSHARK and my iTunes to load them on the iPod currently live and if it costs money it needs to be <$20 cheap.

I am not at all afraid of perl scripts and the like so if there's some bundle of CPAN modules to do it and they will run on ActiveState's windows perl implementation that's plenty fine.

posted by phearlez to Computers & Internet (4 answers total)

I realize this answer is sort of askew to your question, but NPR does stream content over the Internet. There are several apps that will do timed recordings of streams (I'm on a Mac--can't speak to Windows, but I'm sure they're there).
posted by adamrice at 3:11 PM on March 31, 2005

I record NPR through a hauppage card with radio on it and don't have any problems. I do use a filter option on lame to cut off at 15kHz (--lowpass 15) also.

Have you considered maybe it's where the RadioShark is placed (maybe a power source causing interference)? Is there a way to have an external antenna that may be better than it's normal one?

My hauppage card has this hookup that is some weird T-shaped cabled where the bottom of the T plugs into the card and I spread the top out to be the antenna.
posted by cmm at 3:37 PM on March 31, 2005

Response by poster: Capturing the streaming content violates my too-much-of-my-time rule. The RadioShark is moved to as good a location as its going to get - there's still some hiss and it's somewhat variable, presumably based on weather conditions.

I realize I could completely up-end my solution here to avoid this issue but I have a setup that I am happy with, I would just like to be able to do a pass through the file and remove a constant minor noise. If the choices are live with it or completely alter my setup, I pick live with it.

Here's hoping I don't have to.
posted by phearlez at 4:22 PM on March 31, 2005

This explanation of audacity might be useful.
posted by craniac at 9:34 PM on March 31, 2005