What I expected to happen was...:
When I turned the friendly mobs noise down to "off" , all friendly mobs like Pigs, sheep, cows, chickens, etc. would cease their noise, and that would be the only changed sound. I expected the mining noise to be under "blocks" since you only hear it during the process of breaking blocks.

What actually happened was...:
When I turned the friendly mobs noise down to "off" , all noise made by the process of breaking blocks ( not the actual breaking ) turned off in addition to the normal friendly mobs noise turning off.

Steps to Reproduce:
1. Attempt to mine/break any block, and listen to the sound it makes while breaking
2. Go to options, and go to Music and Sounds
3. Scroll the volume down on Friendly Creatures until it says "off"
4. Close the options and then repeat step 1, except the mining/breaking sound you heard earlier will not be present. However, note that the sound when the block fully breaks is still present.