Filtering a noisy cicada on a recording....!

Special Interest Groups Audio Processing
1

I took some video clips of my friends as we were waiting outside of a resturant for some other friends. right near us was a mesquite tree with a very noisy cicada http://en.wikipedia.org/wiki/Cicada. sure enough, when I went to watch the video on my laptop, the cheap piezo mic on the camera sure picked up that noisy bug. I got to thinking about the World Cup last year and how they used notch filtering/adaptive filtering techniques on the audio to deal with all those vuvuzelas. Can this be done with Audacity? the cicada noise is of course going to be a much less exact pitch than the vuvuselas (which were mostly at 235 Hz), but it’s noise definitely occupies has a certain high-frequency range. Any advice on how I might accomplish this, while trying to preserve at least some of the sound of my friends’ talking? I know how to convert the video file to a WAV file already.

thanks!

2

The vuvuzelas were all tuned to the same note so it was possible to remove that frequency, (and a few of its harmonics), from the commentary and still have an intelligible speech.

The cicada noise seems more like broadband noise which is impossible to remove.
You could try audacity’s noise “removal”: use the cicada noise when no-one is speaking as the noise profile,
and/or look at the frequency analysis of the cicada noise alone and cut its main frequencies from the whole recording using the equalizer …