Are you talking about debarking. I've seem some dogs that were surgically debarked. They still can bark but very very low sound. The people that I've meet had no choice, their dogs were barking so much and they have tried everything in their power to stop it with no avail. It was the last choice before either eviction or getting rid of the dog(which is not a option for these people.).
However, I heard that puppymill practice debarking also. Okay, people this is going to get graphic so stop reading if you are weak of heart.
The way they do it is by ramming a rod down the dog's throat distroying the vocal cord. However, it's not an exact science and jaws are broken and sometimes the dog dies. But puppymills don't really care about that.
