[Barryk]

This scratchy noise started today behind the Infotainment Display that starts at about 35mph and increases as I speed up.

Anyone ever encounter this problem

 

[MisterBill]

Check for cats under the dash...?

 

[nrvous]

This scratchy noise started today behind the Infotainment Display that starts at about 35mph and increases as I speed up.

Anyone ever encounter this problem

I have something going on in the dash but mine is intermittent and sounds more like it's behind the main instrument cluster. I think the top dash cover pops off so maybe I'll have the dealer have a look at it next time I'm in for service.

 

[simplex]

the HMI module is just behind the main cluster and it has a cooling fan. I wonder if this could be the source of your noise. But in the case Barryk explained, I cannot see why the speed of the vehicle has an effect on this so that could be something else.

 

[timoshev]

Check out this 12 page treasure trove of info called Volt Radio Audio System Info--where you will find great description and pictures of how to remove the dash top panel and other stuff.
https://gm-volt.com/forum/showthread.php?247345-Volt-Radio-Audio-System-Info&highlight=audio