In the last week I had a couple of voicemail messages that did not make sense.  They appeared in some way malicious but I can’t figure out the angle. 

One sounded completely silent but had a somewhat natural but nonsensical text and another one was completely garbled and incomprehensible to me but again the automated transcription came pretty clear.  It feels like hidden nonsense messages within audio but I can’t figure out what could be the use.