I don't think MobiControl lockdown policy diectly block or affect sound in any way.  The only possible side effect I can think of is that the some sound related software module(s) is/are blocked from running because it is not in the application-run-control/kiosk whitelist 

Have you checked sound related options in device's Settings?

Thanks Raymond. In the Application Run Control settings I had only blacklisted YouTube. When I go to add other items I can only blacklist, I do not get an option to white list. 

To whitelist in kiosk would it be necessary to add items to the lockdown display?

Hello Jake Ward,

Thank you for your post, for Android Enterprise device we do not have the option to whitelist application because they're already whitelisted by default, the only applications which are blocked by default are the "system apps" which you can enable it using following script - 

enable_system_app

"bundle_id"

Example - 

enable_system_app

com.google.android.camera

Please let me know if you have any questions or concerns.

Also, if this post has helped you in solving your inquiry, I would request you to mark the particular comment as "is solution", so others may benefit from this information.

Regards,