Chatterbox, not quiet — noisy type (7)
I believe the answer is:
rattler
'noisy type' is the definition.
(something making a rattling noise)
'chatterbox not quiet' is the wordplay.
'chatterbox' becomes 'prattler' (prattle can mean to talk a lot).
'not' indicates named letters should be taken away.
'quiet' becomes 'p' (music symbol for 'piano', ie soft or quiet).
'prattler' with 'p' taken away is 'RATTLER'.
(Other definitions for rattler that I've seen before include "North American pit viper" , "Nickname for a pit viper in the US" , "Venomous snake" , "remarkably fine specimen" , "US snake (colloq.)" .)