Q: Freezing and Audio skips continuously on the person's last sound

Hi jtsang777, 

Thanks for participating in the Apple Support Communities. 

It sounds like your computer is becoming unresponsive and restarting unexpectedly when you play music or videos. 

It may take a few steps to figure out the cause of this behavior, and I'd recommend starting with this guide on the Support site:

OS X: When your computer spontaneously restarts or displays "Your computer restarted because of a problem." - Apple Support

Try this step first if your Mac isn't at OS X version 10.10.3:

install all available software updates until Software Update reports, "Your software is up to date." OS X updates help your Mac handle the kinds of issues that can cause kernel panics, such as malformed network packets, or third party software issues. For most kernel panics, updating your software is all you have to do.

If the behavior continues, scroll down to the "Additional Information" section for many more troubleshooting steps that can help.

Best Regards,

Jeremy