Good noise reduction when editing a podcast is an important skill.
I received a vocal track for Cyber Speak (http://cyberspeak.libsyn.com). Bret’s voice is nice and clear itself. But his new recording environment put a low level of constant background noise into his track. So I pretty much pulled it all out completely leaving just his voice. This worked well because his voice was so strong over the noise. I stacked Soundsoap doing general broadband reduction making sure to adjust the settings so it did not noticeably distort Bret’s voice. That pulled a lot of the noise out or at least down. The problem is I always do RMS leveling on the voice tracks as I have mentioned in a previous post. So if noise is still present you amplify it too. So I stacked one more effect. I used the built in noise reduction for soundtrack pro. The trick was adjusting the threshold up high enough to catch most of the noise floor while relying on Bret’s voice volume to protect it from the reduction. It worked like a charm. See the before and after images below. I show both waveform and frequency views.
This is exactly why I recommend folks record five seconds of “silence” when they start recording. It gives you a nice region to sample noise for good reduction.
If you are curious to hear the final result check out the Nov 21 Episode of Cyber Speak.