Sustain Analyzer estimates how fast the harmonics levels of a note decrease over time.
The level and sustain envelopes of a note’s harmonics define its timbre.
The app shows amplitude graphs of each measured harmonic and its sustain as dB/s metric and decay time (seconds, T60).
Alternatively the app can display the harmonics’ sustain as bargraphs (dB/s).
Sustain graphs of an electric guitar note:
Sustain measurement: harmonic-wise bargraph view of Sustain Analyzer: