Perceive changes surrounding start of the Open (9)
I believe the answer is:
receptive
'open' is the definition.
('receptive' can be similar in meaning to 'open')
'perceive changes surrounding start of the' is the wordplay.
'changes' indicates an anagram.
'surrounding' indicates putting letters inside.
'start of' suggests taking the first letters.
The first letter of 'the' is 't'.
'perceive' is an anagram of 'recepive'.
'recepive' going around 't' is 'RECEPTIVE'.
(Other definitions for receptive that I've seen before include "Open to new ideas, interested" , "Prepared to listen" , "Open to ideas or change" , "Open to new things" .)