For sound, out of ten, the Cargomaster was an 11 and the Belfast a 3. When a Cargomaster was heading towards you on airways you could hear it for what seemed like ages, plenty of time to go and position yourself in the garden to get the full affect.
I think the An-22 came a close second.

Richard

Thanks for the endorsement!:)

Particularly impressive on a dark winter’s night with no other background sound….that drone filled the sky, getting louder and louder.