Why when we are hungry our stomach makes noises?

Typically, these surrounded by friends or worse with someone you like, in total silence and that he does bear! Happens to your guts start to roar
But it happens to everyone and usually relate to being hungry, but why quésucede?

By contractions between the stomach and intestine, called Rumbling correctly. And although these happen all the time, the symphony is compounded when we have no food in the stomach why?
According to BBC, the digestive process in the stomach contracts to mix the food with gastric juices to push food into the intestine also continues to contract to continue with the process.
When no food the stomach and intestines take what is air. That echoes in the empty space producing a bigger sound.