Harshness of tone or manner (8)
I believe the answer is:
asperity
I believe this is a double definition.
'harshness of tone' is the first definition.
(I've seen this before)
'manner' is the second definition.
(I have seen 'rough manner' mean 'asperity' so perhaps 'manner' could also mean 'asperity')
(Other definitions for asperity that I've seen before include "Harshness, bitter coldness" , "Harshness or severity of manner" , "rough manner" , "Harshness of tone or manner" , "Roughness, harshness or coldness" .)