Simplify the following text for a Grade 6 native English-speaking person.
Original: A hearing dog is a specific type of assistance dog specifically selected and trained to assist people who are deaf or hearing impaired by alerting their handler to important sounds , such as doorbells , smoke alarms , ringing telephones , or alarm clocks .
Simplified: The sounds can come from doorbells , smoke alarms , telephones , or alarm clocks .