As a very keen golfer and someone who only rarely fully solves the Listener, I was delighted to see this puzzle this weekend but automatically assumed that the theme was something other than the obvious. Nevertheless I am still a long way from solving it.
For example 13a "Sound quality if Nicklaus's heading great fighter in rough". I think the first two words are the def with no misprint? N + the usual boxer? I can think of a word for an unpleasant sounding voice but the remaining letters do not suggest "rough" :(
11d I have the last seven letters but cannot make anything fit wordplay and def. "Prolonged healing state supports Tiger's second chapter, thousands uplifted".
And as I typed out a request for help with 37 I figured out the parsing lol.