A port? Yes, a noisy one! (5)
I believe the answer is:
jaffa
'a port?' is the definition.
(I have seen 'Israeli port ' mean 'jaffa' so perhaps 'port' could also mean 'jaffa')
'yes a noisy one' is the wordplay.
'yes' becomes 'ja' (I can't justify this - if you can you should believe this answer much more).
'a noisy' becomes 'ff'.
'one' becomes 'a'.
'ja'+'ff'+'a'='JAFFA'
Can you help me to learn more?
(Other definitions for jaffa that I've seen before include "Port in Israel" , "ball of exceptional quality" , "Port near Tel Aviv" , "Brand of oranges (or cakes)" , "Port incorporated into Tel Aviv" .)