Sound made by learner involved in row (5)
I believe the answer is:
splat
'sound' is the definition.
(splatting is a kind of sounding)
'learner involved in row' is the wordplay.
'learner' becomes 'l'.
'involved in' means one lot of letters goes inside another.
'row' becomes 'spat' (spat is a kind of row).
'l' inserted into 'spat' is 'SPLAT'.
'made by' acts as a link.
(Other definitions for splat that I've seen before include "amusing noise" , "Sound of a wet and squishy impact" , "Piece of wood in a chair back" , "Wet slapping sound" , "Noise on landing" .)