Coming back from the beach [1], my 2005 Civic EX starting making an intermittent loud howling noise, but only at speeds above 45 mph or so. The noise seemed familiar, but I could not place it at first other than it was not something a seized bearing or badly slipping belt would make. Seeing a vending machine, inspiration struck - the noise was similar to blowing over the neck of an old fashioned glass soft drink bottle. I stopped, kicked the frozen slush out of the front valence panel - noise did not reappear.
[1] Had it all to myself other than some people out on the lake ice fishing.