Heard no noise from a horse (5)
I believe the answer is:
neigh
'noise from a horse' is the definition.
'neigh' can be an answer for 'noise' (I have seen 'beastly noise' mean 'neigh' so perhaps 'noise' could also mean 'neigh'). I'm unsure of the 'from a horse' bit.
'heard no' is the wordplay.
'heard' indicates a 'sounds like' (homophone) clue.
'no' becomes 'nay' (archaic form 'no').
'nay' sounds like 'NEIGH'.
Can you help me to learn more?
(Other definitions for neigh that I've seen before include "Whinnying noise" , "Comment from Arab" , "Horse's sound" , "sound from the stable?" , "beastly noise" .)