From a purely physical aspect, making yourself heard when wearing a full face mask, not to mention the breathing rate experienced during a 'pucker moment' would of course sound less than 'routine' to a passenger.
When practicing depressurisation PAs in the sim wearing a mask at a previous company, I was very surprised to see a video of myself later on... sounded nervous as hell, even though being i nthe sim I wasn't. The extra effort required probably made it sound so, I would assume the same in this situation. Wouldn't blame them for sounding a bit jittery though- adrenaline does that to people
