Business part of the ear?
The ear is made up as follows:
Outer Ear- ear Flap, ear canal,ear drum, middle ear and inner ear called the Cochlea-from this there is a nerve called the auditory nerve that leads to the brain which carries the information received in the cochlea. Each ear has its own independant auditory nerve (they are not connected in any way)
If blood turbulence flowing through arteries could be heard it is likely the turbulent flow would be in all arteries near both the ears and if it was possible to hear that turbulence it would be heard in both ears not just one.
Tinnitus can be the result of damage in the cochlea where the fine hairs are moved in accordance with the sound transmitted from the inner ear. That type of tinnitus is the result of damage caused to the fine hairs in the cochlea which sometimes become traumatised through excessive sound or when they wear out due to age.
I hope that explains roughly how sound arrives at the brain from the ear flaps.
Tinnitus is also caused by many other factors, very high blood pressure and rotten teeth are just two other possible causes, there are many more.
It can be no co-incidence that many tinnitus sufferers have tinnitus due to being associated with high sound over a long period of time. Additionally a significant amount of elderly people also have tinnitus.