Several people have (rightly) mentioned this and I couldn't help but think of some Hollyweird movie I once watched on a flight.
Typical action movie, total badass warrior main character. He's with someone else in a commercial building, pursuing and being pursued by the bad guys. Hero good guy is armed with a SCAR(7.62, I believe) and lights it off full-auto. In an enclosed, concrete stairwell. And then just starts talking to his buddy like "omg we gotta keep going this way" or something, who of course, can easily hear him.
I thought, yea I don't think it works like that. Deaf with a side of TBI, most probably.
Edit: and to stay on topic, I think you'll need a SPAS12 or SPAS15 for proper home defense. Ain't nobody got time that pump stuff.