Luckily smoke detectors and true (loud) emergencies seem to punch right through without any issues.

I wear ear plugs every night. The disposable foam ones are good enough to prevent me from being woken up by my partner getting ready before me, but I would most certainly hear a fire alarm. I'm laying in bed right now with them in and I can still hear the fan pointed at me. They significantly reduce low-mid range frequencies, but they're not 100% soundproof