First of all, sorry to hear that your son has been dealing with multiple ear infections this year. I am happy to give you some information about ear infections and management decisions, but I must point out the obvious...that these typed responses do not in any way compare to the history and exam that can be obtained from a visit with your physician.
In order to understand why patients develop ear infections, you must first understand something about normal ear anatomy and physiology. Normally sound waves enter your external auditory canal and bounce into the tympanic membrane (ear drum). There are 3 bones of hearing (malleus, incus, stapes) that are attached to the tympanic membrane that move when it moves transmitting the vibration to the cochlea which sends an electrical signal to your brain. The middle ear (everything medial to the tympanic membrane) must be aerated to work well. The air gets there through something called the eustachian tube which goes from the back of the nose to the middle ear.
There are several theories about ear infections in children, but most of them involve the idea that for some reason the eustachian tube isn't working properly (due to decreased angle, swelling from viral URI's, or large adenoid tissue that is blocking it in the back of the nose) which leads to negative pressure in the middle ear that sucks fluid into the middle ear and creates an effusion that can repeatedly get infected. Removing the adenoids may help, but it also may be worth considering ear tubes as well. I would recommend talking to an ENT (ears nose throat) doctor
. Hope this helps.