Tinnitus can be described as "ringing" ears and other head noises that are
perceived in the absence of any external noise source. It is estimated that 1
out of every 5 people experience some degree of tinnitus. Tinnitus is
classified into two forms: objective and subjective.

Objective Tinnitus
Tthe rarer form, consists of head noises audible to other people in addition
to the sufferer. The noises are usually caused by vascular anomalies,
repetitive muscle contractions, or inner ear structural defects. The sounds
are heard by the sufferer and are generally external to the auditory system.
This form of tinnitus means that an examiner can hear the sound heard by the
sufferer by using a stethoscope. Benign causes, such as noise from TMJ,
openings of the eustachian tubes, or repetitive muscle contractions may be
the cause of objective tinnitus. The sufferer might hear the pulsatile flow
of the carotid artery or the continuous hum of normal venous outflow through
the jugular vein when in a quiet setting. It can also be an early sign of
increased intracranial pressure and is often overshadowed by other neurologic
abnormalities. The sounds may arise from a turbulant flow through compressed
venous structures at the base of the brain.
Subjective Tinnitus

This form of tinnitus may occur anywhere in the auditory system and is much
less understood, with the causes being many and open to debate. Anything from
the ear canal to the brain may be involved. The sounds can range from a
metallic ringing, buzzing, blowing, roaring, or sometimes similar to a
claanging, popping, or nonrhythmic beating. It can be accompanied by
audiometric evidence of deafness which occurs in association with both
conductive and sensorineural hearing loss. Other conditions and syndromes
which may have tinnitus in conjunction with the condition or syndrom, are
otosclerosis, Menier's syndrome, and cochlear or auditory neve lesions.

Hearing loss, hyperacusis, recruitment, FMS, and balance problems may or may
not be present in conjunction with tinnitus.

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