I met a dog with surgically partially removed vocal cords to soften her barking, which was also the time I learned that such a thing was possible.
After researching, I've reached a conclusion: it should be done to more whumpees.
Yours is too loud? Their screams are ringing in your ears? You're tired of listening to their rants, but enjoy their pleading enough to want to leave them some voice?
Perform devocalization on them today to ensure they never manage anything more than a husky whisper!