I did a stupid thing.  I recently bought and installed an Oneida Supercell dust collector without getting prior approval from the family dog.  It turns out that the sound of the machine (higher pitched than most dust collectors) terrifies her and/or hurts her ears.  So I have three choices: 1. Sell the Supercell at a loss, buy a traditional cyclone and replace all of my 4” ductwork;  2. Build a sound-insulating closet around the Supercell and train Sunny to live with the remaining noise; or 3. Invent tiny noise-cancelling headphones for dogs and teach Sunny how to put them on.  I’m planning to build the closet, using rockwool sound-deadening insulation and a solid-core door, but I’d appreciate any ideas anyone might have, on this option or the general issue of dogs and workshop noise.  Thanks.