Pleased you sensibly and logically isolated the tyres as the cause of the problem. It's a characteristic of low profile tyres. The wider the tyre 'footprint' the more the tyre wears, so the more surface area of the tyre is in contact with the road surface and the more noisy the tyres will be. This tends to start happening after the tyres are two thirds worn. Also the brake pressure compensator valve can malfunction causing the rear tyres to very momentarily lock up on braking and this creates an uneven wear pattern.