How do i turn off this alarm and what does it mean?

[Prebenm]

Every time i sit in a plane (any cind) this annoying beep alarm starts. I can’t find out how to turn it off... 

https://youtu.be/y-3f8zKq490

i tried to press the MKR button but it didn’t work...

PLEASE HELP

[Geir Haugmo]

The video was a little short.

But it sounds like it might be an ID from either VOR or NDB.

The vide starts with  something bit something like an" U" and vontinues with several "A"`s.

Go to the audio panel or one of your Nav radios to cancel the sound.

[Geir Haugmo]

Hmm. Måtte inn å sjekke audiopanelet til C-152.

Det ser ut som det er en bug. Jeg tunet  inn GRM VOR på NAV 1.

Jeg får identnår jeg velger NAV 1 på audiopanelet, men jeg må trykke NAV 2 for å kutte audio.

Noen som har sett lignende?