The most common and most likely answer to this crossword clue is the 6 letter word NEIGHS
I've seen this crossword clue in The Daily Telegraph
N
E
I
G
H
S
More clues leading to the result NEIGHS
- We may hear objections, beastly sounds
- Sounds of stable hinges breaking
- Sounds of denial — straight from the horse’s mouth?
- Those opposing audibly, making beastly noises
- Negative MPs shouted out cries from the Shires?
- Beastly noises from Doctor Singh injected with drug
- Dissenting chorus on the radio with some animal sounds
- Shires may give these votes against broadcast
Buddy explains!

The straight part
We know that "beastly noises" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case beastly noises = neighs.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 NEIGHS mean?
NEIGHS noun- The cry of a horse.
- (of a horse) To make its cry.
- To make a sound similar to a horse's cry.
- To scoff or sneer.