Hi Trevor,
Unfortunately I am not sure if the noise started after I changed the tyres as I usually drive with music and I noticed the noise one day I drove early in the morning with no music. So I am not entirely sure. My rear tyres nead changing soon, therefore I would get new tyres put them on the front and move the present front hankook tyres and move them to the rear and see if anything changes. A few people heard the sound and told me it's coming from the front. So when I swap the hankooks to the back I will see if there's any difference.
Cheers