That office building alarms are worse is all the more annoying since they theoretically shouldn't need to wake people from sleep.
A coworker did pat my shoulder to let me know, and I noticed the super loud fire alarm as soon as I removed the quiet headphones.
The headphones were not noise-cancelling or anything. Just Sennheiser HD380 Pro, which provide ~30dB isolation. I don't think it would have been possible for fire alarm to be noticeable under such conditions unless it was loud to ear-damaging levels.
This suggests that alternative indicators than just sound should be in place, such as automatically turning off lights and switching to emergency lighting.
The commercial building fire alarms have flashers on them for just that reason. Deaf people need to know the building is on fire too.