Hiss and laugh about start of rehearsal (7)
I believe the answer is:
crackle
'hiss' is the definition.
The definition and answer can be both related to natural events as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'laugh about start of rehearsal' is the wordplay.
'laugh' becomes 'cackle' (cackle is a kind of laugh).
'about' means one lot of letters goes inside another.
'start of rehearsal' becomes 'r' (I am not sure about this - if you are sure you should believe this answer much more).
'cackle' going around 'r' is 'CRACKLE'.
'and' acts as a link.
Can you help me to learn more?
(Other definitions for crackle that I've seen before include "Sound as of burning sticks" , "sort of porcelain" , "Make the sound of a fire" , "Rustle loudly" , "Sound of burning wood or squeezed paper" .)