The OP has a valid point. The sound of a large caliber handgun going off next to a wall can be very disorienting. I don't suggest doing a lot of this but being prepared could allow you to get off followup shots instead of being disoriented from the first time you have ever heard a gunshot without protection.
I once had a coon get into the mud room and got the brilliant idea to shoot it with my 30-30, I have to say that's one idea you only think of once because my ears rang for a good 2 weeks after that. The stupid things you survive as a teenager!
I won't have that problem. I've been deaf since age 2. Also, I'll never hear anyone breaking in. Once, a cop broke in and I never heard it. He woke me up by flashing his flashlight in my face.
Once the hearing is lost, it nevers comes back. Save the probably-never-going-to-happen SD discharge exposure for the real thing. You won't notice it at the time, and a bit of ringing is better than loss of life or injury.
My left ear is still ringing from foolishly shooting a .22 almost two years ago without hearing protection. I can hear out of it, it's just very slightly muffled. It's still ringing.
I wish it was easier to get a supressor. I really only want one for HD. "Hang on, BG, while I roll up these ear plugs. It'll take just a second for them to expand". I want to end a life threatening situation, but I'd like to keep my hearing as well while shooting indoors.
There is absolutely no way I'd sacrifice my hearing to prepare myself for what might happen during a SD situation. A single gunshot can permanently damage your hearing and as others have mentioned, hurt your SA.
Your choice on whether or not it's worth it to you and what your hearing is worth to you. I love music and there's not a chance that I'll do anything to purposely damage it. I may never need to use a firearm in SD, but I know I want to hear as well as possible for the rest of my life.