Possible Clues:

• Dependable type of job on the radio
• Reliable staff one's hired to work in TV or film
• Dependable type of job for one employed for The Hearing
• Reliable member of film crew?
• You can depend on him for a row (5, 3)
• You may rely on always hearing from him
• He may be relied on to make 28 down
• He may be strong but he won't be silent
• You may rely on 15 across not to keep silent
• He's allowed, by the sound of it, to be relied on