Gen 2 ABS accumulator noise at high altitude

I recently replaced my 2008's ABS accumulator and was happy to find it went from sounding like a blender full of rocks every 10 seconds to dead silence.

We then took the car on a long road trip that included time at 6600 feet. While at high altitude, the ABS accumulator occasionally made a new chirping sound. I found some posts about brake system noise from the wheels at high altitude, but nothing about noise from the accumulator itself.

There were no codes, no change in brake feel, or any other problems. The noise stopped when we descended and as far as I can tell everything is fine.

I'm posting a sample of the noise here in case it helps someone in the future.

 

I didn't do the work myself so yeah, I guess it is possible. But since there were no operational problems and we only go to altitude every few years I decided not to worry about it.