The most common and most likely answer to this crossword clue is the 4 letter word OINK
I've seen this crossword clue in The Daily Telegraph
O
I
N
K
More clues leading to the result OINK
- Noise from Tamworth pub largely repressed by fine?
- Sanction to restrict home producing beastly sound
- Reason not to write copy one in pen?
- Sound like a farm animal – a duck? Something in a pen?
- Reason pen’s useless making pig cry
- All right to hold in animal sound
- Piggish remark no problem around home
- Beastly noise the reason tattooist might stop?
- This swine might do tattoo with nothing upfront
- Why a printer won’t print noise?
Buddy explains!

The straight part
We know that "Animal noise" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case animal noise = oink.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does OINK mean?
OINK noun- The sound made by a pig, or an imitation thereof.
- Of a pig or in imitation thereof, to make its characteristic sound.
- Representing the sound made by a pig.
- Drawing attention to male chauvinism (from the term male chauvinist pig).