Question for SCD-1 Owners

I recently purschased a Sony SCD-1. I am quite happy with it. I do have a question though. The unit makes a little noise whe loading a disc. It sounds like something moving around. It's not overly loud, but it is just as loud as the door closing on the top. The sound is great and it seems operate flawlessly.

Is this sound normal?? AS you can see, I have little to no technical knowledge. Thanks