Subaru Steering noises

I have a 2000 Subaru Outback Wagon, ~180,000 miles. Recently I noticed, probably because I didn’t have the radio on, a medium-pitched warbling sound when I turned the steering wheel to about 11:00 (left) or 1:00 (right). It was more prominent turning left. It the frequency SEEMED tied to speed, but it was hard to tell. Kinda sounded like a little bird tweetering. Couldn’t tell if it was coming from front or back. I’m hoping it’s benign and/or cheap to fix.