i have been hearing thumping sounds in my left ear.. so decided to find out what it is.. so..

In pulsatile tinnitus, people hear something resembling their heartbeat in their ear.

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 untreatable. Nevertheless, rarely pulsatile tinnitus can be caused by more serious problems -- 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.

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.

so i guess it is pulsatile tinnitus. irritating sound.