The term 'ringing in the ears' is a medical condition known as tinnitus. Tinnitus is a condition where a person experiences a ringing, buzzing, or other sound in their ears that is not caused by an external source. It can be caused by a variety of factors, such as exposure to loud noises, ear infections, and certain medications. Tinnitus can range from mild to severe and can have a significant impact on a person's quality of life.