Weird FaceTime noises

I was FaceTiming my friend, and in the middle of the call a loud noise started to occur as if someone was packing up thing and if someone was by a plane. It was super loud, I scream to my friend asking what is that and no response. Then the loud sounds went away and I said my friends name one more time, this time they responded. I asked what was that and they didn’t know what I was talking about. No noise was coming from their end.