Fuss created by welcoming everybody who should be heard (8)
I believe the answer is:
ballyhoo
'fuss' is the definition.
(commotion or excitement)
'by welcoming everybody who should be heard' is the wordplay.
'welcoming' means one lot of letters goes inside another (in sense of 'inviting in').
'everybody' becomes 'all' (I've seen this before).
'should be heard' indicates a 'sounds like' (homophone) clue.
'who' is a homophone of 'hoo'.
'by' enclosing 'all' is 'bally'.
'bally'+'hoo'='BALLYHOO'
'created' acts as a link.
(Other definitions for ballyhoo that I've seen before include "Fuss; noisy publicity" , "Brouhaha" , "Noisy or sensational publicity, hype" , "song and dance" , "Blatant advertising - a holy lob (anag)" .)