No, I can't say it does. A friend has a Colt Delta and his sounds the same to me.Does it increase the report? My SR1911 10mm is definately a lot more to shoot than any of my other 10mm handguns.
It does reduce the recoil a bit. I like the way it shoots, about like a M1911 in .45 ACP.Ruger doesn't typically offer factory porting on their SR1911 models, so chances are the previous owner had it ported aftermarket. You'll probably notice the porting helps with recoil management, especially with the punchy 10mm rounds, which is great for quick follow-up shots.
If you're curious about the exact work done, a quick call to Ruger with the serial number could confirm whether it left the factory that way, but most likely, it was a custom addition. Let us know how it shoots!