Huh...I thought spoke before my last post, just could'nt think that it would make a noise you found hard to diagnose.
Also thought broken axel but it would'nt neccesarily show up not as a noise anyway.
Had a squeek on the front when when I stopped kept looking and looking, speed sensitive, dry rubber axel seal.
Off touring got five miles and a rubbing noise, thought brake related so disconected it , took a while and could'nt ride it with cable off without noise
Split rim, cured and made ridable home by deflating tyre