Brief Answer:
It could be pulsatile tinnitus

Detailed Answer:
Welcome to health care magic, I share your concern and I will try to help you out in best possible way.
The description you have given fits into a condition called pulsatile tinnitus where people hear something resembling their heartbeat in their ear . The twittering in the ears is called tinnitus in medical terminology which could be due to variety of reasons, but when associated with pounding sensation, its more likely to be pulsatile tinnitus.
Pulsatile tinnitus is usually due to a small blood vessel that is coupled by fluid to your ear drum. It is usually nothing serious and also usually untreatable.
Rarely pulsatile tinnitus can be caused by more serious problems like aneurysms, increased pressure in the head (hydrocephalus), and hardening of the arteries. A vascular tumor such as a "glomus" may fill the middle ear, or a vein similar to a varicose vein may make enough noise to be heard.
Inner ear disorders that increase hearing sensitivity can cause pulsatile tinnitus. As this condition can be corrected surgically, it is one of the few "fixable" causses of pulsatile tinnitus.
There are some very large blood vessels -- the carotid artery and the jugular vein -- that are very close to the inner ear (see diagram above). Noise in those blood vessels can be conducted into the inner ear. Accordingly, other possibilities for vascular tinnitus include dehiscence (missing bone) of the jugular bulb -- an area in the skull which contains the jugular vein, and an aberrantly located carotid artery. An enlarged jugular bulb on the involved side is common in persons with venous type pulsatile tinnitus.
Anything that increases blood flow or turbulence such as hyperthyroidism, low blood viscosity (e.g. anemia), or tortuous blood vessels may cause pulsatile tinnitus.
Hence I recommend you to consult an ENT specialist and get clinically evaluated for pathology in eardrum, ossicles etc.. so that your symptoms can be clinically correlated. wishing you good health.
Hope this clarifies your doubts. Revert back to me if you have follow up queries.
Dr. Naveen XXXXXXX
Medical Consultant.
Ebix, Inc.
YYYY@YYYY

---