The testing takes the CVR out of its normal operation, as all the circuits are tested and your should hear a beep from the speaker. Thats why its tied to PB-Set as well as the erase button.
1. of course. I often erase the CVR on ground, especially if we were talking about "serious issues"
2. If the PB is not set you nust dont hear the beep, and the test is unsucsessful. or what exactly are you asking?
If you want to stop it from listening while airborne, just pull the corresponding Circuit Breaker.
