TargetTalk

folded towel in front, phone book behind. It will never wear out. And is pretty much silent.

I've shot thouands of rounds, and it hasnt worn out, actually the pellets dont go past the towel.

I've shot a 30 fpe .22 caliber airgun into it, and it holds fine. (our pistols are about 4-5 fpe)

Try a Steyr LP10. I had one for a while. I am a rifle shooter but thought I'd like to try A/P so I got an LP10. I have a shop in the basement and sometimes I get in trouble from my supervisor for shooting when I ought to be working on honey do projects. I always get busted when shooting my air rifle. I was totally amazed at how quiet my LP10 was. Nobody could hear it at all upstairs. I thought maybe the little holes drilled into the top of the barrel might reduce the muzzle blast but don't really know. I sold it because everytime I shot it I felt I should be practicing with my rifle. Beautiful pistol though.

All the above comments both interesting & informative.
However , as a "fail-safe" simply buy your missus a MP3 player , download all her favourite songs , crank it up , stick it on her head , and then go any shoot until you can shoot no more !