Comparing two frequency spectrum plots

Hi. I am currently working on a project where a clip of white noise is detected, and I would like to compare the difference in sound level for different frequencies between two audio files. However, to my knowledge, the sound level for each audio file will be normalized to the sound level amplitude of each individual file, so two audio files will be normalized at different numbers, and I will not be able to compare between the two audio files directly. Is there a work around so they are normalized to the same sound level amplitude? Thank you. Sorry if it has been asked before

No, that is not the case. Plot Spectrum normalizes the amplitudes according to the “Size” setting in Plot Spectrum. As long as you use the exact same settings in Plot Spectrum, you can directly compare the plots for different audio selections.

Oh I see. So you’re saying that for the same size of the frequency spectrum plot, the 0 dB maximum would be the same sound level for both plots?

Yes.

For the “Spectrum” algorithm, a 0 dB sine wave should be displayed as (about) 0 dB on the spectrum plot. In practice it may not be exact due to various reasons including interpolating data points and resolving to screen pixels, but it should be close. Changing the “Size” will affect the displayed level because a larger “Size” means more “frequency bins”, so a narrower range of frequencies are caught in each bin.