Audacity Forum

formeruser wrote:Your comment about -80 dB being not credible scared me.

I agree that -80 dB seems a bit low.

If you really are achieving -80 dB with the recording level turned up enough to get a good strong recording (peak level around -6 dB), then try holding a mechanical wristwatch about 10 cm from the microphone, then Normalize the "silent" recording to about -6 dB. Can you hear the watch ticking? With my setup and my watch, I can hear the ticking though it is almost buried below the background noise. When set up for voice recording, my gear / recording space has a noise floor of around -70 dB, and that is too high to get a clear recording of my wristwatch.

I'm using the contrast method. I leave silence at the beginning and end of each chapter and then I compare the speech to the silence and it routinely comes up -80 dB. The difference between speech and silence is around 32-36.

Thanks to Steve. I believe that I have not set my recording level high enough. I'm getting around -12 peaks when I'm recording. I was worried about clipping. Also I remember reading about gain staging a long time ago and I know it's not usually a good idea to max out the input gain on any piece of equipment, so I set my interface at about the 75% mark (I guessed. The dial is not calibrated) and did the same in Windows, about .75. I didn't want to go higher because I thought I would get more noise. I think that the way I did it is usable for this project, since I passed an ACX check, but in the future I suppose that I'll record a bit hotter.
I like the wristwatch technique. I'll try that.

And that is precisely why the ACX Robot tests for noise and peak distortion and overall volume. It doesn't count if you have a terrific noise floor, but your show has to be boosted 15dB to be heard.

That's also a good place for the ACX Check tool instead of Contrast. It gives you all three numbers in one swat.

http://wiki.audacityteam.org/wiki/Nyqui ... #ACX_Check

Also:

http://forum.audacityteam.org/viewtopic ... 23#p297423

Koz