With 7.0 came an extensive overhaul of the sound design for the classes and their combat abilities. Personally, I found many of them to be too abrasive and distracting when put into the context of the fast paced combat as it is now. There are many, many loud sounds playing frequently and they often overlap with eachother (such as swings, skill impacts and then weapon impacts all playing over eachother at once) which exasperates the problem.
I have edited the sounds for some of the most commonly spammed abilities in warrior rotations to reduce their intensity, such as Slam, Devastate and Bloodthirst. Most of them have been shortened in length to reduce their constant overlapping with eachother, and EQ:d a bit to tone down some of the loudness. Slam is the only one that has been replaced completely, and it should now be your weapon impact that is the dominant feedback rather than the original very slappy Slam sound.
To clarify, this is NOT the kind of sound addon meant to make things sound more awesome or cooler, like you often see for hunter guns and such.
Extract the Sound directory into your root WoW folder (example: C:\World of Warcraft\). The correct full folder path once installed should be \World of Wacraft\Sound\Spells\