I just got a new roku 4K 55” tv in the past two weeks. Just recently if I go to my cable, it’ll make a high pitch noise and if I change a channel on the TV through my cable box, it’ll do it again.
Thanks for the inquiry.
Please contact your TV's manufacturer directly to report this issue and request additional support. Each Roku TV manufacturer provides direct support and warranty services for their products running the Roku OS.
For a list of contact information for Roku TV manufacturers, visit our Community page here: Contacting Support for Your Roku TV