Why does my laptop suddenly freeze and causes a high pitched tone?

The high pitched tone might be an alarm, indicating a hardware fault or something out of tolerance.  Out of tolerance issues could be a high temperature alarm (a component is overheating). It could indicate a fan failure or voltage out of range. 

However, an alarm isn't the only cause. Sometimes, electronic components interact to create audible sounds.  Your sound could be normal for the circumstances. Or, it could be caused by a failing component.  

It would help to know more about the noise. I don't suppose you could record it and upload an audio file somewhere, and give us the link? 

I don't know what might have cause the laptop to freeze. Modern computers slow themselves down when they are overheating, but, AFAIK, they don't come to a complete stop.

Comment: One place where I had a job assignment received some power supplies that made noise. At manufacturer's expense, the power supplies had to be tested. The ones that made noise were sent back to the factory. (These were server power supplies, not for laptops.)

Things like that are usually caused by hardware faults. I would check RAM and disk(s) health as well as voltages and temperatures of CPU and GPU.