Like others, I have experienced this situation. The sound of the guns (.45's and 9mm's) going off, (mine and theirs), was not an issue. Oddly, my ears did not ring afterword either.
But, last time I fired my Glock 30 .45 without protection (I was hunting, rather than defending my life) it really hurt my ears and they rang for a long time.
The other day, I fired my 9mm +P and my .357 Sig while in the same exact hunting elements as the Glock 30 .45 and they did not hurt my ears at all. No pain, no ringing.
From my conclusions:
#1 loudness of the gun is a moot point when you are defending your life and it probably won't damge your ears either.
#2 .45's are damn loud (especially short barreled ones).
#3 I don't care what anyone says, the .45 is one loud sumbitch and the .357 Sig just ain't that loud. The .45 literally damaged my ears for a week, probably permanently, and the .357 Sig didn't even leave me with any ringing at all.
Cops have been using magnum loads for defense for almost a century and I have never heard of one complaining about the noise in a shooting. To answer your question, it won't be an issue at the time or afterword.
[This message has been edited by Red Bull (edited March 13, 2000).]