Speaker's pretty terse before start of speech (7)
I believe the answer is:
tweeter
'speaker's' is the definition.
(tweeter is a kind of speaker)
'pretty terse before start of speech' is the wordplay.
I cannot quite see how this works, but
'pretty' could be 'twee' (I've seen this before) and 'twee' is found in the answer.
This explanation may well be incorrect...
(Other definitions for tweeter that I've seen before include "One relaying notes" , "hi-fi unit?" , "part of speaker" , "Social networker" , "little Speaker" .)