In recent days I got multiple voicemails that are just static noise. They are about 1:01-1:03 long. Sometimes Active Armor marks these numbers as Spam Risk, sometimes not. My guess, is spammers are trying to leave an empty message just so a victim will call back thinking it is a pocket dial. Or they are trying to play calls flagging AI, by screwing statistics on the amount of non-dropped calls.
Just a heads up for AT&T spam call division employees. Ideally, I want messages without inaudible speech (e.g. just static/white/VoIP noise) to be removed -- there are plenty of simple algorithms to do that.