2005 Honda Civic sounds like a motorboat

I have a 2005 Honda Civic that I bought certified pre owned. Over the past few days, I noticed that when I accelerate over 25 mph or so, the car starts to sound like a motor boat or like someone is riding a moped next to my car. It sounds the same if I am going 35 mph or 65 mph. When I accelarate the noise doesn’t get louder, its a constant level once I’m over that 25 mph mark. When I slow down to stop at a red light it winds down and stops. When I idle, I hear no noise except the normal engine sounds. What’s going on??

Check for loose plastic splash panels in the wheel wells. Could be pushed against the wheel or axle when the wind is blowing.