Ringing in the ears is a common problem. The is medically known as tinnitus. I would recommend seeing your primary care doctor
as there can be some serious as well as some reversible causes that require attention.
There are two types of tinnitus (broadly speaking). Objective tinnitus is when there is a sound made by the outer ear that you are constantly hearing. Causes of this include muscle spasms in the ear, vessel inflammation (you hear the blood flowing), or vessel narrowing. Your doctor can evaluate for these causes.
The more common type is subjective tinnitus--where the nerve (known as the acoustic nerve) misinterprets sounds and causes the ringing sensation. The most common cause of this is noise induced. It is common in people who use ear plug headphones at high volume levels--if you do this I would recommend stopping for a period of time. Medicines can cause this (aspirin, ativan). Another cause is a structural problem--like a wax buildup or a buildup of fluid behind the ear drum (or tympanic membrane). Primary nerve problems or tumors are a rare, rare cause.
If you have any hearing loss this could be signs of a more serious condition. For example, Meniere's disease, which includes vertigo symptoms as well.
Some of these conditions require medical attention otherwise permanent damage could be done. You should not take a risk with your hearing. I recommend seeing your primary care doctor. He or she may refer you to an audiologist
or an ear-nose-throat doctor
who could further evaluate this.