Macbook Pro 2014 makes a "burp" sound.

So about three weeks i got a brand new Macbook Pro medio 2014 after my old Macbook Pro medio 2010 died.

I decided to start fresh with the new computer so other than transfering all my files i got all programs/apps from scratch.

But now after three weeks/a month the computer is starting to say a "burp" sound every ca. 30 second. The sound comes from the (build in) speakers, and it's not connected to any programs as it's still there even if I close all programs. The sound gets louder if i turn up the speakers.

The strange thing is that my old Macbook 2010 also said this sound. But here it seems to do it all the times, where it is only sometimes on the new one and can be stopped by restarting the computer.

Hope this makes sence and somebody know a way to fix this problem. Thanks.

I can upload a recording of the sound if that helps.

Patrick