Tinnitus emissions (SOAEs), which are faint high-frequency tones that are produced in the inner ear and can be measured in the ear canal with a sensitive microphone, may also cause tinnitus. About 8% of those with SOAEs and tinnitus have SOAE-linked tinnitus, while the percentage of all cases of tinnitus caused by SOAEs is estimated at about 4%. Some people experience a sound that beats in time with their pulse, known as "pulsatile tinnitus" or "vascular tinnitus". Pulsatile tinnitus is usually objective in nature, resulting from altered blood flow, increased blood turbulence near the ear, such as from atherosclerosis or venous
Tinnitus in the central auditory system, and therefore cause tinnitus. The most common cause of tinnitus is noise-induced hearing loss. Such hearing loss may also be present in a hidden form, i.e., in persons showing a normal audiogram. Hearing loss may have many different causes, but among tinnitus subjects, the major cause is cochlear damage. Ototoxic drugs can also cause subjective tinnitus, as they may cause hearing loss, or increase the damage done by exposure to loud noise. Those damages can occur even at doses that are not considered ototoxic. Over 260 medications have been reported to cause tinnitus as a