alps\frameworks\base\packages\Keyguard\src\com\android\keyguard\KeyguardViewMediator.java
#1384 行左右:
///M: [ALPS00827994] always to play sound for user to unlock keyguard
mSuppressNextLockSound = false;
改动:
///M: [ALPS00827994] always to play sound for user to unlock keyguard
if (authenticated) {
mSuppressNextLockSound = false;
} else {
mSuppressNextLockSound = true;
}