They accept what is sound (4)

I believe the answer is:

ears

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'they' is the definition.
Both the answer and definition are plural nouns.
Perhaps there's a link between them I don't understand?

I cannot understand how the rest of the clue works.

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(Other definitions for ears that I've seen before include "Auditory organs" , "Lugholes" , "Corn; organs" , "Spikes (of cereals)" , "Lugs (colloq.)" .)

I've seen this clue in The Globe and Mail.

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