They stop interruptions being heard (6)
I believe the answer is:
brakes
'they stop' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Perhaps you can see an association between them that I don't see?
'interruptions being heard' is the wordplay.
I cannot quite see how this works, but
'being' could be 'rake' (rake is a kind of being) and 'rake' is found within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for brakes that I've seen before include "Slowing or stopping devices" , "Devices for reducing speed or stopping" , "They work to slow a vehicle" , "carriages" , "They slow or hinder progress" .)