Hi Vicky
I have a 17 month old son, and all i can say is like father like son!! seriously vicky dont worry, my little man has the loudest pumps and sometimes it really is unbelievable that it can come from such a little body!
it seemed to settle down a bit, but at the end of the day far better he can get the wind out than have it stuck inside giving him tumy ache! if you are at all concerned then defo speak to your hv just to put your mind at rest, but i think it sounds like typical male behaviour!! 
Hope this helps you some? xx