Tinnitus is the perception of elementary nonenvironmental sound or noise in the ear. This is most usually a subjective phenomenon (i.e., heard only by the sufferer), occurring in the absence of acoustic stimulation. It may occur in conjunction with either conductive or sensorineural hearing loss. However, in about one-fifth of sufferers, tinnitus is objective (i.e., heard also by an observer). This may result from:
- Vascular causes: e.g., arteriovenous malformation, fistula; carotid or vertebrobasilar bruit
- Mechanical causes: e.g., palatal myoclonus (ear click). The common causes of subjective tinnitus are:
- Middle/inner ear disease: cochlear hydrops (Ménière’s disease), presbycusis, acoustic tumor
- Pulsatile: normal heartbeat, glomus jugulare tumor, raised intracranial pressure, cervical/intracranial aneurysm, arteriove- nous malformation.