Sound out the listeners with oldie from Daniel Defoe (6)
I believe the answer is:
deafen
'sound' is the definition.
The definition and answer can be both related to change as well as being verbs in their base form.
Perhaps you can see an association between them that I don't see?
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for deafen that I've seen before include "what heavy rock stars do?" , "Render senseless" , "Render unable to hear" , "Need FA (anag.)" , "Blowing a trumpet in someone's ear would do!" .)