Quiet-ish drill-like sound coming directly from phone

(iPhone 17 Pro) My phone recently has begun periodically emitting this really high pitch whistling sound -- almost like what a drill makes (with the speed and metal noises). Literally no idea what it is and it's lowkey freaking me out... It happens when I'm connected to my Air Pods AND when they're disconnected, so it's literally something IN my phone -- genuinely out of nowhere. Phone isn't overheating, working fine etc. Should I be worried? 😰 Definitely will take it to a technician person at some point if it becomes more common... Anyone else?