Possible Clues:

• Some sound effects
• Pay a girl, perhaps, for stealing others' work
• They may be found in long halls
• One gets a good return from such, by the sound of them
• Returning sounds
• Natural sound repetitions
• You get them back, by the sound of it
• Parrots, in a way
• By the sound of them, thay end with 18 downs
• From which you'll always get a good return, by the sound of it