It probably is the tyres. The wider they are and the lower profile they are, the noisier they will be as they begin to wear because more rubber is in contact with the road surface. In summer you can reduce the noise by going for harder compound low rolling resistance tyres, but, because they are harder compound, they tend to be noisier and less grippy in the winter. Or go down a wheel size or two and fit narrower, deeper profile tyres.