Weird buzzing noise- ES350

[webzo]

Hello,

I have 07 ES350 with about 80k miles on it. When driving, I hear a weird buzzing noise from the right-front side of the car. The noise sounds close to how it would sound when I operate the side mirrors. It is short, lasting about 2-3 seconds at most. Its completely random and I notice it only when the car is standing.(waiting for a light to turn green, for example). I have asked my passenger to look for the noise and because it is sudden, short and random, then haven't been able to pin point the location. Its somewhere to the right. It doesn't have any impact other than irritating me for the past few years...

Any ideas?

Thank you for your time.

[gbhrps]

webzo,

Possibly the HVAC fan changing speeds, or one of the HVAC actuators opening or closing one of the blend doors on the heater box?