Mine even rang it's bells at every half-hour and hour. So 12 loud bell rings at midnight. In my bedroom. I slept well.

Honestly I think it's because I get used to the sound. If the ticking and ringing are always there, the brain just ignores them, even in sleep. For subjectively nice sounds (like those of a nice pendulum clock) at least.

I don't have it running anymore, the weights would eventually hit the piano.