This morning as I was just waking up to the comforting sounds of hearing my dog barking to be let out at 7 am, I thought «Okay just another normal day». (kelleyaroura.com)
The three main classes of assistance dogs are guide dogs for the visually impaired, hearing dogs for the hearing impaired, and service dogs for those with physical or mental / cognitive limitations. (breeders.net)
Yes, shelter dogs have frequently been used as hearing dogs in the past. (prisonpetpartnership.org)