A couple of solutions
Early in life I used light bulbs to wake up. I got "flasher buttons" from the hardware store. They just go in the socket, then you screw in the light bulb. It makes the bulb flash even with constant power. Hooked it to a timer to serve as alarm clock. Power in dorms does not fail that often, and I moved around for years with the contraption that was just 3 of these flasher things with 100 watt bulbs. Woke even me up reliably. Could also pick up door bell, via a relay. I am sure a simple relay could interface something like this to a fire alarm and all parts are hardware store stuff.
Now that I live in a house I built, things are more complicated. A big strobe light in every room running off a common power supply and microcontroller. Also has LED lights in every room like you can get for RVs. Runs off big batteries in case of power failure. I figured it out - it uses 250,000 watts. Of course, the flash is only for 10 microseconds, so mean power consumption is not that much, but it is still one honking big cable from my solar batteries. Works for burglar, fire, tornado, alarm clock, doorbell and phone. For lesser alerts, such as freezer temperature, excess water usages, or fax arrival, it just uses the LED lights and a single CFL lamp in my office.
Even so, I have to flash up on the screen when there was an alert, because even then, if I am looking closely at something bright, I might miss an entire event. That and head in the pillow are actually tough problems to solve completely.
I see I am not the only one who had to roll-their-own. Stuff you really need is just not available. Somebody should sell good, powerful whole-house strobe systems that hook to a small laptop or PC for control. They should use a wall wart for power and also take a battery. Wireless network for control. Most people do not want to run all kinds of wires in their house.