What is the attack phase? How do we measure it?
- The sound ramps up from zero amplitude to its highest amplitude. Relative amplitude.
Wrong measure. - The sound ramps up from zero amplitude to its highest amplitude. Time.
Excellent! - The sound ramps back down to a somewhat lower amplitude level. Relative amplitude.
Decay; wrong measure. - The sound ramps back down to a somewhat lower amplitude level. Time.
That is decay.