Why is my Lumia 950xl making a strange new sound at hello screen lock screen stage?

[Windows Central Question]

At the "Looking for you..." stage of unlocking my Lumia 950XL, since today I'm getting a little electronic sound just after pressing the side unlock button. I press the unlock/power button to wake up the phone...it goes to lock screen and starts the Iris scanner and "Looking for you..." and makes this weird 3 second or so tinny electronic sound. Most annoying, and I don't know where it came from or how to turn it off. Anyone else have this issue?