What is "hearing dog"

n. A dog trained to assist the deaf, alerting the deaf person to doorbells, smoke alarms etc.

n. dog trained to assist the deaf by signaling the occurrence of certain sounds

A hearing dog is a type of assistance dog specifically selected and trained to assist people who are deaf or hard of hearing by alerting their handler to important sounds, such as doorbells, smoke alarms, ringing telephones, or alarm clocks. They may also work outside the home, alerting to such sounds such as sirens, forklifts and a person calling the handler's name.