It's possible that the pulsating noise you're hearing is caused by a tire out of round or an imbalance. However, since the tire shop and the Toyota dealer have checked the tires and found nothing wrong, it's also possible that the noise is within an acceptable tolerance for the type of tire you have. It's not uncommon for
some tires to make more noise than others, depending on the tread pattern and design. If you are still concerned, you could try rotating the tires to see if the noise changes. If it does, it may indicate that one or more of the tires is causing the issue. Otherwise, it may be something that you'll have to learn to live with. It's also a good idea to consult the tire's manufacturer for recommendations or warranty.