Sound indication that there’s pork for dinner? (9)

I believe the answer is:

crackling

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'sound' is the definition.
(crackling is a kind of sound)

I cannot understand how the rest of the clue works.

(Other definitions for crackling that I've seen before include "Pork covering" , "Crisp skin of pork joint" , "Crisp exterior of roast pork" .)

I've seen this clue in the Evening Standard.

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