Buzzing noise on live view and Playback?

[Cromer1]

recently had a HILOOK NVR - 104MH-C/4P and four Hilook collar vu cameras .I have notched that when in ''Live view' on iPhones via the ProControl+ app get a slight background buzz noise. We are have the NVR set to record both audio and video as we need the audio on playback .Any suggestions ?

Also - have logged into the user interface via the NVR's IP address to access the web based interface and cannot get playback or live view either a windows laptop and also on MacBook..

I have power off the system and rebooted and still get both issues ..

Thanks in advance for assistance .( based in the uk )

 

[Cromer1]

EDIT ;-

I have resolved the playback / live view issue of payback on laptops - needed to put the code into the recipients device ( above the QR Code on the NVR system menu ) to enable sharing of encrypted files etc...but still having problems with the buzzing on live view . Audio is on when I click on the camera to view on my phones but goes away when I click two way audio. I have no mics on cameras but although the audio is quieter it is without any buzzing

 

[Cromer1]

still getting buzzing on live view and playback...although it seems better quality audio when I click the two way audio button on the Pro control plus app..even though or cameras dont have a mic