To be heard, I yell for cold sweet (3,5)
I believe the answer is:
ice cream
'cold sweet' is the definition.
(cold dessert)
'to be heard i yell' is the wordplay.
I cannot quite see how this works, but
'be' could be 'am' and 'am' is found within the answer.
'heard' could be 'e' (I've seen this in other clues) and 'e' is present in the answer.
'i' is within the answer.
This may be the basis of the clue (or it may be nonsense).
'for' is the link.
(Other definitions for ice cream that I've seen before include "Frozen desert" , "cone?" , "Cold snack" , "Hot day treat" , "Cool summer confection" .)