Help identify this sound?

Thanks in advance here!
I have had several Prius over the last 15 years and love them. I've never had to do anything beyond scheduled maintenance but also never kept one beyond 180000 miles. However, I'm looking at 220k on my 2012 and yesterday I got in the car and the traction, brake, check engine, abs and exclamation lights are all on. I had to drive across town and it ran fine, but the hybrid battery indicated did not seem to ever get above halfway, and from watching the screen, seems like the regenerative brakes are perhaps not working. And it's making the noise in this linked video here whether the gas engine is running or not.

Some quick research seems like that's perhaps pointing to the brake actuator, looking for some confirmation, and advice from the community on whether that's right or other diagnoses before I try to find an honest, reasonable and capable hybrid mechanic in Brooklyn. Speaking of which, I'm a newbie on the forum, but are there resource lists for recommended mechanics by region?

with appreciation,

-Joe