A SOUND EAR II - Association of British Orchestras

A SOUND EAR II
Since then, other studies have also shown high levels of hearing damage in musicians. Heili Laitinen found:
% of Respondents
Tinnitus Hyperacusis Distortion Diplacusis
All
24
25
12
5
Women
18
31
14
6
Men
27
21
11
4
Eskko Topilla found that levels of threshold shift were similar to the general public, but tinnitus and hyperacusis were
both four times more common.
Tinnitus 2 is triggered and aggravated by many factors, one of which is certainly noise. Two people with identical
threshold shift will have quite different tinnitus experiences, but there is little doubt that increased noise exposure
increases the risk of developing tinnitus, even if there is no clear correlation with the intrusiveness of that tinnitus
(which is dependent at least as much on the character of the tinnitus as on its volume). We found that 35-40% of
musicians have frequent or occasional tinnitus, with the woodwind being much more likely than other sections to
report frequent tinnitus. Other researchers have found that a fifth of players have permanent tinnitus, and 2/3 have
tinnitus after rehearsals or performances (demonstrating temporary hearing damage). Of the players with tinnitus, we
found that 30% are bothered by it and 6% are very bothered (at least double the level for the general population).
Hyperacusis is an over-reaction to some noise. You will be familiar with the way your ears prick up when you
hear your name mentioned, or hear a phrase that interests you: this is due to a survival mechanism in which the brain
increases the volume of noise it considers to be important. This can be noise which has a special interest for you,
which represents special responsibilities (eg. your child) or is associated with danger. Regrettably, noise associated
with stress or pain is classified as dangerous. When players are exposed to noise that hurts them, or which increases
performance stress by preventing them hearing their own output or actually preventing them playing for a moment
(because of the shock), their brains activate the ‘dangerous noise’ defence mechanism – and make the noise seem
even louder. More than a quarter of the woodwind report hyperacusis. The reflex can also activate the fight-flight
mechanism, leaving a player shaking with adrenalin and with muscles tensed.
Hyperacusis is not ear damage, but a learned change in perception and with help it can, to a degree, be unlearned.
13
Recruitment can seem to be the same as hyperacusis, but it is not. As the stereocilia become damaged,
each one becomes less sensitive and less specific. This will happen to a group of stereocilia, with the result that
none of them reacts to a very quiet noise. Eventually, as the noise increases, it hits the (new) trigger point of the
damaged stereocilia. As the noise increases, an increasing number of neighbouring (damaged) stereocilia also start
reacting – whereas in an undamaged ear the reaction would be restricted to a much smaller range of stereocilia. The
consequence is that as a given noise level rises, the damaged ear hears nothing, nothing, nothing, nothing, something,
lots, far too much – as the floor of your hearing rises, so too the ceiling of your hearing comes down.
Cocktail party effect occurs when hearing damage makes it difficult to distinguish a particular noise
against high background noise levels. For many people, this is only a social disability but for musicians, it also means
you cannot listen to particular instruments against the general sound of the orchestra.
Diplacusis results from your ears having a significant difference in frequency selectivity, producing clashing
interpretations of the tonal content of the noise. Because it is unusual to have the same damage in both ears, this is
not uncommon.
2
Tinnitus - the perception of abnormal sound whose location is within the body - is quite common. There are
many, many causes but some occurs when regions of the brain tuned to frequency regions that have become
damaged are reassigned to the same frequency regions of adjacent areas, leading to a sort of aural doubleaccounting:
A high proportion of people have some experience of tinnitus: 10% of the under-50s and some
40% of the over-50s have tinnitus that is bothersome in the quiet. About 5% experience moderate to severe
annoyance, 1% find it has a severe effect on their quality of life, and 0.5% suffer a severe effect on their ability to
lead a normal life.