Why does my laptop speaker keep turning off?

I have a lenovo laptop, whenever i try listening to something or watching a movie/video the internal speaker turns off. The only way to get it to come back on is to pause the media and mute it then un-mute it and the sound comes back on for 1-5 minutes.
any ideas?

Sounds like a driver issue, your drivers are either corrupt or missing. Search on google the exact model of your laptop and look for audio drivers. Download and install good luck!