Tinnitus is a sound heard in one or both ears, such as ringing, buzzing, or whistling. It is usually caused by ear conditions, certain drugs, a blocked ear tube or canal, or head injury. Symptoms of tinnitus include phantom noises like ringing, buzzing, clicking, whistling, or hissing heard when no external sound is present. Treatments for tinnitus include medications that can stop the ringing in the ears.