Yes Deaf ferrets will still make sounds at times they can even be a little more vocal. We have 2 who are very deaf and a couple we think are just hard of hearing (both of these are Spotted Pandas). Both of them(deaf) Dook occasionally a lot of hissing and Angel when startled sometimes will even Bark. -- Shanon, Mitch, Callie (cat), Kerowac (iguana), Brambles and Rose (hedgehogs), and last but not least The Den of Thieves (ferrets-Switch, Smokey, Blaize, Tamara, Polar Bear, Diablo, Chiquita, Prancer, Angel, Critter, Chevy, Sunny, Red, Cupid Cuddles and Puddles) and one Foster ferret Bandit [Posted in FML issue 1885]