Sound from ref, ending in shrill note at end of game (7)
I believe the answer is:
whistle
'sound from ref' is the definition.
'whistle' can be an answer for 'sound' (thesaurus). I am not sure about the 'from ref' bit.
'ending in shrill note at end of game' is the wordplay.
'ending in' suggests the final letters.
'at end of' is a charade indicator (letters next to each other) (some letters go at the end of others).
'game' becomes 'whist' (whist is a card game).
The final letters of 'shrill note' are 'le'.
'le' put after 'whist' is 'WHISTLE'.
Can you help me to learn more?
(Other definitions for whistle that I've seen before include "L.S.White (anag.)" , "What ref blows" , "He wilts (anag.)" , "Blow through teeth" , "Make cheerful sound" .)