This one is driving me nuts and I'm wondering if it connected to the ANC. My 2011 Accord with automatic and 190 hp engine has a high pitched whine at several speed ranges (similar to what you might find on an AM channel when there is some interference). It sounds like it is coming from the speakers, whether the radio is on or off. At 50 mph is comes on (goes away a couple of mph above) and then again at 70 to 74 mph. At constant speed it constantly whines in those speed ranges when the accelerator is on. Within 1/2 second of lifting the accelerator the noise stops, even if the speed stays the same, like when going downhill. I can accelerate from 70 to 80 and noise is there, but when decelerating with the throttle lifted there is no noise as the speed drops through the range. It is the same whether driving on asphalt or concrete so it is not the tires. I do a lot of highway driving and this problem is getting to me!

 

i would start by disconnecting the ANC mic.

 

I disconnected the front mic but could not disconnect the one in the trunk (the plug wouldn't budge). I then noticed low frequency rumblings but no cessation of the high pitch whine at 60 and 72 mph. I saw that the ANS is only supposed to work at low frequencies so I'm starting to think I have a air intake problem, especially since it goes away as soon as I lift off the throttle. I will post my question in the general troubleshooting forum as well.
Thanks, Alan.

 

ah - it could certainly be engine related.