2005 Subaru Outback sedan noise behind dash

idearequest

My 2005 Subaru Outback sedan has a new noise today whether it's just running on the battery or with the motor on. The car was driven a lot yesterday with no noises, and it was not driven today. It seems like it's right behind the dashboard and sounds like a mechanism trying to engage or disengage. Or someone else who listened thought it could be a liquid, but it didn't sound fluid to me -not sure tough. It continues for a while when the car is turned off. Anyone heard of this before?

Thanks very much!