Tinnitus--Introduction
AUD 733 Week 1
Tinnitus Definition:
From the Latin tinniere (to ring) Refers to an auditory perception not produced
by an external stimulus Commonly described as a ringing, roaring,
hissing, or whooshing Ranging from high pitch to low pitch or even
a noise-like sound (with no tonal quality)
Pronunciation Controversy Tin’-i-tis (stress on the first syllable and
the middle “i” uses the short pronunciation)
Tin-i’-tis (the middle “i” is long and the usual pronunciation of the suffix “itis” is used
The controversy goes on
The Arguments The researchers and some individuals from the
American Tinnitus Association (ATA) argue that “itis” should be pronounced with a long “i” , as described in numerous dictionaries
The majority of other individuals use the short vowel sound for the middle “i” and may argue that “itis” with a long “i” suggest some sort of inflammation which is not accurate when referring to tinnitus
Suggestion Use whichever pronunciation you are
comfortable with Explain briefly to your patients that they
may here either pronunciation used and both are acceptable
What Tinnitus IS NOT Auditory hallucinations are not the same as
tinnitus Auditory hallucinations may be
psychological or may have a true neurologic foundation
More on What Tinnitus Is The exact pathophysiology of tinnitus is
unknown Many Mechanisms have been sited as
possibly producing tinnitus Outer hair cell decoupling from the tectorial
membrane Hyperactivity of neural firing Hypoactivity of neural firing
Cont… Improper functioning of the olivocochlear
bundle (efferent auditory pathways) resulting in a lack of normal inhibition
Basic Concepts on the Origin of Tinnitus It is the chronic perception of a sound that
has no external source. The auditory sensation is continually generated by aberrant neuronal discharges in the auditory nervous system
The brain erroneously interprets the signal as sound/s
Site of Origin The cochlea seems like a likely site because we
know that damage to the cochlea from salicylates (aspirin), noise exposure, and other factors produce tinnitus
But surgical severing of cranial nerve VIII with tinnitus remaining present points toward a central rather than peripheral origin
Postulated course of tinnitus(by Sweetow in Hearing Disorders, Ed. By Jerry Northern (1996))
“An acute insult (or offending agent) leads to a chronic signal, which leads to a central modification, which leads to psychological enhancement, which leads to intractable tinnitus.”
Characterizations of Tinnitus As mentioned earlier, tinnitus can vary in
pitch, loudness and tonal quality It may be constant, pulsed or intermittent It can arise suddenly or slowly It may be heard in the ear/s (tinnitus
aurium) or in the head (tinnitus cranii)
Classifications Literature describes objective and
subjective tinnitus Objective-is audible to an observer (using a
stethoscope or by listening near the ear) Present in less than 5% of overall tinnitus
cases Usually a cause can be determined and
treated medically
Cont.. Objective Tinnitus
Usually associated with vascular or muscular disorders Arteriovenous aneurysms, abnormally patent
Eustachian tube/s, glomus jugulare tumors, palatal myoclonus, spasms or tics of the stapedius or tensor tympani muscle/s
Often pulsatile and synchronous with the patient’s heartbeat
Subjective Tinnitus Audible only to the patient The most common, occurring in over 95% of
tinnitus patients ( we will focus on subjective tinnitus for the rest of this course)
Associated with practically every known otologic disorder
Also related to a host of nonauditory pathologies See separate chart/page in course content for
pathologies associated with subjective tinnitus CLICK HERE to view page now
Epidemiology View information from the Tinnitus Data
Registry developed by the Oregon Health Sciences University (OHSU). It has been in existence since 1975 and has some data published at http://www.ohsu.edu/ohrc-otda/otda.html
Prevalence in the U.S. 40-50 million Americans experience
chronic tinnitus Approx. 2.5 million are debilitated by the
tinnitus
Other Facts About Tinnitus Approx 60% bilateral 30 %, unilateral 10% perceived in the head About three times more men than women
seek treatment for tinnitus Why?
If a person has transient episodes of a tinnitus-like sound, it would not be considered chronic. If tinnitus occurs occasionally and only lasts a few minutes per episode, it would not be considered pathological.
What Makes Tinnitus a Problem? It is not known why tinnitus becomes or is
a problem for some individuals and not for all who experience it. It is suggested, however, that individuals already predisposed to psychological disturbances are more likely to be negatively impacted by the existence of tinnitus.
Correlates No absolute correlation between the quality of the
tinnitus and the etiology For example, low-frequency roaring tinnitus is often
reported with Meniere’s disease but NOT always, and roaring tinnitus can occur with other conditions
It is unknown if acoustical qualities correlate with the perceived severity of the problem For those who seek treatment, the loudness and pitch of
the tones “matched” to the tinnitus do not predict the severity of the problem. We do not have data on those who are not bothered by their tinnitus and do not seek intervention.
Subjective Rating of Tinnitus Loudness
On a scale of 1 to 10, 1 being the “softest sound imaginable” and 10 being the “loudest sound imaginable”, most of the subjects (70%) rate their tinnitus loudness between 4 and 8. About 20% rate it between 8 and 10, and 10% rate it below 4.
Information From the Tinnitus Data Registry