My experience is similar. Occasionally I have been woken from sleep with a sudden extremely loud noise in my head. The first one was an explosion, then a loud clapping noise, or it could be a chain clanking. The noise is sooo loud that I wake up instantly but I know immediately that I am not in danger as it is very obviously inside my head. I googled "loud noises in head"and discovered that there is a condition known as ëxploding head syndrome". Amazing !! Each sufferer seems to experience different noises and reactions so this could be what you have. My noises have not happened in several months and I think that they may have had something to do with stress or anxiety or something like that because they did not proceed on to something worse. The other possibility is maybe a side-affect of a medication as I am on a few ! I did not tell the Dr in case she thought I was crazy.
Hope yours goes away soon. m