What Causes Abnormal Sound In Ears?

I can hear my heartbeat in my ears constantly other noises as wel extremely loud also when i turn my head to the left or lightly touch my scalp or left side of face I hear a zinging sound which lasts for a few seconds - I have ha these problems for almost a year - thank you I hav seen an ENT specialist without result I have had an MRI an had my carotied artery checked - thank you