Slow errr errr noise at high speed with new tires

My 2008 Subaru Outback just got new tires and now is making an errrrr errrr noise on the highway. It is slow (like 3-5 seconds per errrr). Only above 45MPH.
Any idea what that might be? The tire place did a wheel alignment at the same time.

What are the tires? Some tires are just noisier than others.

Bridgestone Serentity Plus (Turanza). The strange thing is that it does not always happen. When driving to work, I don’t hear it for the first 10 miles or so on the highway. Driving home I hear it when I get on the highway.

Check the lug nuts and confirm that all the tires are the same size… exactly the same size.

Is it possible it is related to the road? - and don’t forget that pavements can be different on each side of the road.

If all is mechanically OK with the car this could be a “harmonic” effect of the tires. The changing road surfaces can impact whether or not a harmonic is set up.

If the new tires are much quieter overall, this might allow you to hear a bad wheel bearing or CV joint going bad which the older noisier tires would have “covered up” with more road noise.

With an '08 car you might have the wheel bearings and CV joints evaluated, but I suspect this is just a property of your new tires.

Could the noise be the result of grooved pavement?