Oticon Real with CROS - Unknown sound

Every now and again I get this very fast digital sound (like a short ring) in my Oticon Real/CROS but I don’t know what the hearing aid is trying to tell me. It’s either notifying or warning me about something.

It’s not a battery warning.

I have checked the manual but it doesn’t specifically mention this sound I am getting.

Not sure if the sound is coming from the CROS to notify there is someone speaking from that side. Does the Oticon CROS have that function?