isolate a specific frequency

I have a video recording of an outdoor wedding that has a great deal of background noise from air conditioners and the minister can be barely heard. Reducing background noise with Audacity does no good, as my guess is that the frequency of the minister’s voice is similar to and buried in the background noise. Assuming I have a good recording of the minister from another venue, is there a way with Audacity to use that to identify his frequency and then eliminate all other noise frequencies except his from the wedding recording? I would have no problem matching the audio to the video.

Thanks in advance for any suggestions or just letting me know it can’t be done.

I think you’re outta luck. Voices aren’t one frequency. They’re whole collections of pitches, tones, inflections and combinations, and they take up the whole middle of the range of audible frequencies. I have somewhere the analysis of one single piano note. It takes up over a third of the audible spectrum.

Your task is CSI Forensics: “Pull” the voice out of the trash and prove the bad guy did it before the final commercial.

So doing it the way you want is pretty hopeless…but the show isn’t. When Hollywood gets stuck with a problem like this, they get the minister to repeat the words into a terrific microphone in a super quiet room, record the whole thing and some production type with strong coffee substitutes the clear words for the ratty ones in the video. You play the video to the minister so they can match the lips, probably more than once.

I’m not joshing. It’s called looping. Of course, you need to be pretty good at editing to pull this off, but it can be done (unlike what you want to do). Not all movie shoots come away with good audio.

If you do it right, people will come up to you wanting to know how you did it.

We won’t tell.


Some improvement may be possible if you remove all the frequencies except the range essential to understand speech, include 200Hz to 4000Hz , exclude everything else. If you do that it’s going to sound like a voice on the phone, but may be easier-to-understand , or just less-unpleasant , than the original soundtrack.


It won’t be theatrical any more. And that is the goal, right? “The happiest moment in my life…etc” probably doesn’t sound like a noisy telephone call.

Ooo, Ooo. If you have access to the church, you can get a much closer acoustic match to the original performance by micing the minister in the exact place he was standing. Just obviously much closer.


Thanks to all for your replies. Based on what you provided, I managed to get some improvement in screening out the noise. Thanks again.