There is a setting in the Settings/ Options/ Applications menu.

Warn when talking while microphone is muted.

If this is checked, and the Sound pack is set to Deactivated, then when you talk while the microphone is muted, you will not get the warning sound.

This setting should not depend on the Sound pack being activated.

It should work when it is checked.

If for whatever reason the user doesn't want to hear all the coming and going messages, I still believe they would want to be notified when they are trying to speak with their mic muted.

At least I would.