Could still be a form of tinnitus.
http://www.jacksonearclinic.com/pages/pitinnitus.htm
"A rare type of objective tinnitus is called muscular tinnitus. One hears a rhythmic twitching noise or fluttering noise in the ear. This can be caused by an irregular contraction of one of the two ear muscles in the middle ear that are attached to the hearing bones. This is very similar to the twitching of the eyelids that some people experience upon occasion. Muscular tinnitus can be related to caffeine intake, lack of sleep, and stress. It can also occur independent of any apparent cause. Also, the muscles in the throat that open and close the Eustachian tube from the nose to the ear can have a similar spasm and cause muscular tinnitus. This form of tinnitus usually resolves with time. If it does not resolve in a short time, low doses of anti-seizure medications can usually stop the contractions. If these prove ineffective, the muscles in the middle ear can be cut to stop their contractions by a minor surgical procedure."
Granted this is the internet... So may be best to check with your doctor?
Like it's plugged up? Could be excessive moisture and earwax build up from sealing your ear canal too.
My friend has to get his ears cleaned at the doctors/audiologist every so often as he produces excess wax and builds up a blockage.
I'd consider consulting your doctor. Could be an ear infection too.