Mic meter has a pulse even though mic volume is muted?

Hello friends,

I am very confused, and perhaps that is why I am hearing static and white noise even though I am recording total silence.

Here is what I am doing: I disabled the built in mic, I muted the USB Samson co3u mic, and also lowered the mic level on both the computer and audacity. With all that done I am still getting the mic meter flickering between 50 to 60 db.

Shouldn’t the mic meter be still with no pulse, since I disabled any chance of recording?

Please help explaining.
Thanks a lot!

It depends on how the muting is done. -60dB might be the amount of noise in a good microphone amplifier when you unplug the microphone but left the amplifier running. It could also be the amount of noise in the system if you left analog Line-In running but defeated the microphone channel.

If you record it, Effect > Amplify, and do Analyse Spectrum on it, do you get a nice carpet of more or less flat noise? or do you get a very serious series of sharp spikes at the right-hand side? Flat noise is probably portions of the analog audio system still running. Sharp spikes could be digital instabilities – such as what happens when you run a USB microphone through a USB hub.

Creating digital noise is not unheard of, but it’s pretty rare.