There are excellent arguments on both sides of the noise vs. power debate. I have shot off a .38 + P off indoors, and I did experience temporary hearing loss for about a year. I have no doubt that .357 magnum rounds, and for that matter almost any other caliber, has the capacity to do permanent damage to your eardrums.
However, if you are forced to use a handgun in a home defense situation, which is by almost any measure not the ideal tool for the job (a shotgun would be preferable), then the consequences of failure to stop an assailant far outweigh the consequences of firing rounds off without hearing protection.
Its a tough call, and one that must be made by each individual. Depending on multiple factors, the range of sound for each caliber will vary as well.
Relevant to this debate are issues concerning penetration as well. Whats behind your target? If its sleeping children or you live in a crowded apartment building, .357 magnum is also a questionable choice.
Personally, I wouldn't worry about sound too much. If you can, get a 12 gauge shotgun for HD. If you have to use the .357, you have many options. I err on the side of power. But be careful where you are shooting and what you are shooting at and don't let the panic of a flash-bang freeze your nerves.
I have my Gp100 loaded with 2 Speer Gold Dot .357 125 grain magnum rounds, then two Underwood Gold Dot .357 158 grain magnum rounds, then two more Speer Gold Dot 125 grain magnum rounds.
For my 640 I use the Buffalo Bore & Barnes 125 grain copper round, and for the last two shots use the Underwood 158 grain.
For .38 special in my 442 I use the Corbon DPX 110 grain Barnes copper round and the Speer Gold Dot 135 grain short barrel load.
http://www.youtube.com/watch?v=Q7w4M-LNXuQ
the winner of the 9mm vs .45 argument is clearly .357 magnum
-Heylookaneagle