What is an ADSR Envelope?

An ADSR Envelope is a specific type of envelope used in sound synthesis that controls how a sound evolves over time using four stages: attack, decay, sustain, and release. It is known for shaping the dynamics and character of a sound.

The attack determines how quickly the sound reaches its maximum level, the decay controls how it drops after the initial peak, the sustain sets the level held while the note is sustained, and the release defines how the sound fades after the note is released.

An ADSR Envelope emphasizes control and expression, allowing sounds to be crafted from sharp and percussive to smooth and sustained.

It is commonly applied to amplitude but can also modulate other parameters such as filter cutoff or pitch.

Today, ADSR Envelopes are fundamental in synthesizers and audio production, valued for their ability to shape the timing, dynamics, and feel of a sound.