### SignalProcessing.Compute.AudioRelated.SignalEnvelope

This node creates an envelope signal $\mathrm{A}[n]$ for shaping a sound signal $x[n]$ over time, e.g. for the simulation of a key press on a piano. To this end, the sound signal $x[n]$ is typically multiplied with the envelope $\mathrm{A}[n]$:
$x'[n] = \mathrm{A}[n] \, x[n]$
The parameters attack, decay, sustain time, and release are given as percentages of the total envelope length. Together with the sustain level input, these parameters control the shape of the envelope:
$A[n]$
$n$
Attack
Decay
Sustain Time
Sustain Level
Release