How loud is the signal?

Audacity Help Forum macOS
1

(macBook Pro, Leopard)

I’m still trying to figure out which noise reduction settings to use. Found this advice in Librivox Wiki: http://wiki.librivox.org/index.php/Detailed_Audacity_Noise_Removal

“For example, if the loudest part of your signal is at -10dB and the noise is at -70dB, then you will want to amplify by 10 dB to get your signal to 0dB (which is standard). That will raise the noise levels to -60dB, which is all but inaudible. If the loudest part of your signal is much quieter, say -40dB, then you will need a lot more amplification to get a decent output level, namely 40dB. That amount of amplification will raise the level of the noise to -30dB (-30 = -70 + 40) which is much more audible and intrusive. It sounds about as loud as background noise in an office.” (end)

My very basic question is, how do you figure out what the loudest part of your signal is? Do you read it off the track waveform? If so, is there anyway to “magnify” the vertical space the track occupies so that you can zoom in for a more accurate reading?

Thanks

2

It may not matter, but the link is broken.

Select the track (so that it is highlighted) and then from the Effect menu select “Amplify”. Don’t apply the effect - just look to see how much the effect is offering to amplify by. By default the Amplify effect will amplify to 0 dB, so if the effect says, for example, “Amplification (dB): 12.4” then that means that the current peak level is -12.4 dB (minus 12.4).

3

Steve,

If anybody wants to see it, the URL on the bottom of the page is:
wiki.librivox.org/index.php/Detailed_Audacity_Noise_Removal

Thanks for your excellent explanation.