Protection being needed, they often take note (4)
I believe the answer is:
pads
'protection being needed' is the definition.
I can't tell whether this defines the answer.
'they often take note' is the wordplay.
'they often' becomes 'pas' (I am not sure about this - if you are sure you should believe this answer much more).
'take' means one lot of letters goes inside another.
'note' becomes 'D' (musical note).
'pas' enclosing 'd' is 'PADS'.
Can you help me to learn more?
(Other definitions for pads that I've seen before include "tablets" , "Bolsters" , "flats?" , "Walks softly" , "Protective guards worn by sportspeople" .)