LUFS

Loudness Unit Full Scale (LUFS) is a measurement of the perceptual loudness of an audio signal. This crate contains a function for computing the loudness of an audio signal, represented in 32-bit floats and sampled at 48kHz.

I'm not sure that the algorithm is correctly implemented here, but at least it gives qualitatively half-reasonable results.

lib.rs:

The reference material for this crate is the ITU technical report available here