EG, ENV, Envelope
A dynamic Module in Synthesizers to form a continious movement, applied to an amplifier (VCA) the envelope can change the sounds contour (amplitude in this case) and makes it sound "percussive" or "with a long fade-in and fade-out" to swell like water on a beach.
the Standard Envelope Form is ADSR, which start with Attack Time (A) from Minimum Level to Maximum, falls back to Sustain Level (S) with Decay (D) time. After key release with Release time (R) the signal will go back to 0 (if Sustain Level was 0 nothing happens after Decay time has passed).
Multisegment Envelopes allow to set times and levels, the best and most flexible forms are time-level envelopes, the more segments they have the more complex it can be, the most complex envelopes can be found in software like NI Absynth or FM8 (try synthDB to check for them)
Envelope ist das engl. Wort für Hüllkurve.