attack 1) The buildup of sound when an instrument is bowed, blown, struck, or plucked. 2) The ability of a system to reproduce the attack transients in musical sound. Poor attack makes a system sound slow.
attack transient The initial energy pulse of a percussive sound, such as from a piano string, triangle, or drum head.

from:
Stereophile: Sounds Like? An Audio Glossary
by J. Gordon Holt, July, 1993

attack 是強調"initial 起"的意思,譯作: 起音???