How does the decibel scale correspond to volume?

Audacity Help Forum macOS
1

This is about the decibel scale on the frequency analysis window.

If you add up all of the y coordinates along the frequency graph, would the resulting decibels equate to the overall volume of the track?
So even if there is a peak that goes up to 0dB, you would have to add up all of the decibels from all frequencies in order to get the volume of the track. Am I correct in thinking this?

I understand that decibels are a logarithmic scale so it’s not as simple as just linearly adding -18dB and 0dB for example.

I’m writing a paper on the Fourier transform, so any help regarding this would be appreciated.

2

The scale in “Plot Spectrum” is normalized such that a 0 dB (peak level) sine wave will be displayed as (approximately) 0 dB.

The sum of all frequency bands does not relate directly to the overall level, and is dependent on the “Size” (window size) setting. (The window size relates directly to the number of frequency bins in the FFT analysis).