I have an 05' Hybrid Honda Accord, whenever I am at 38-40mph and 55-60 I am hearing a humming noise (sounds like I'm drifting out of the lane and hitting those grooves in the road to notify I'm out of my lane). If I accelerate or slow down the noise goes away. Also if I go right past those speeds I don't hear the noise at all. I've taken the car in several times for this issue, and honda hasn't been able to identify the problem. I've gotten everything checked top to bottom, including the tires and transmission and nothing has a problem. I've also kept up all my scheduled maintenance at the honda dealership since I first purchased the car.