For the purpose of this document the word “deaf” will be
used to refer to all age groups and to the complete range of hearing loss
including people who are deaf, deafened, hard of hearing and deafblind, unless
otherwise stated.
What is deafness ? Deafness
is the term applied to the total or partial inability to perceive sound. In
physiological terms there are two types of deafness. Conductive
deafness, which means that there is some difficulty in the physical
structure of the ear (e.g. with the ear drum or bone structure), causing failure
to properly relay sound impulses to the hearing nerve.
Conductive deafness can often be helped by surgery or other clinical
interventions. Nerve
deafness, which means that there is some problem in the nerves in the inner
ear which relay
information to the brain.
There is generally little that can be done to counter the effects of
nerve deafness.
Deafness
can also be classified by age of onset. Prelingual
deafness, refers to deafness at birth or in the early stages of childhood,
and relates to the fact that no spoken language has been acquired at the time of
onset. People
who are prelingually deaf often have difficulty with spoken language and
literacy, and generally communicate most effectively through sign language. Acquired or adventitious deafness is the term applied when a person who has had hearing becomes deaf at some point during their life. They have the advantage of knowing spoken or written language and are more able to deal with lip reading and text.
Is
the effect of deafness similar to blindness ? Deafness
and blindness are both conditions caused by sensory loss, but other than that
they are quite different, especially in terms of implications for the individual
and in social recognition and acceptance. Blind people generally experience sympathy and help, whereas
deaf people often encounter frustration and rejection. Helen Keller, a famous woman from America who was both deaf and blind, described the difference as.....”Blindness cuts you off from things, but deafness cuts you off from people”.
What
causes deafness ? Deafness
can occur or be acquired because of many different factors, either through
individual disposition or by external influences. For
example, deafness at birth is frequently caused by the rubella virus (German
Measles), or by genetic factors which can lead to deafness being an inherited
trait. Acquired deafness can be
caused by many things including illness, accidental injury, viral infection,
excessive noise, reaction to drug treatments, etc. The most
common, overall cause of deafness is ageing.
As a person gets older the ‘mechanical’ parts of the ear (e.g. the
ear drum and the ossicles) wear out or get damaged, or the nerves may gradually
deteriorate. Most people over the
age of 70 have some significant degree of hearing loss. Some types of deafness can be overcome or reduced by medical intervention. However, nerve deafness is generally a permanent condition.
Do
all deaf people have the same experience of hearing loss ? The
experience of deafness differs from individual to individual. This can be influenced not only by the type of deafness or
age of onset, but also by the degree (or volume) and pitch (or tone) of the
hearing loss. Many people are deaf
in one ear but not the other, or have different degrees of loss in each ear. The extent
of normal human hearing (i.e. from the lowest
frequency that can be heard, to the highest) covers an extensive range of
sounds. The sounds made by the
human voice, while also covering a range from basses to altos, form only about
half of the range of sounds that a normal ear can hear. Thus some people can hear particular sounds such as the
booming of a drum or the ringing of a bell, but have difficulty with hearing a
human voice. Since not all deaf people have the same hearing loss, this means that some people can hear some high sounds but not low sounds and vice versa. Even within the range of sounds from the human voice, some deaf people may be able to pick up parts of words but not others, thus making speech difficult to follow. Simply increasing the volume can make some sounds clearer, but may make others uncomfortably loud.
How
is deafness measured ? While
there are standardised “hearing tests”, there are no formal or medical
measurements by which different types or deafness can be classified.
Instead there are generalised categories which attempt to differentiate
deafness by the way in which the hearer can or cannot cope with hearing the
human voice. Different agencies
(e.g. health, education or social work) may use different
classifications. Some
general classifications are as follows: Hard of
Hearing Moderate
deafness Severe
deafness Profound
deafness
What is the incidence of deafness ? Unlike blindness, there is no legal requirement for local or
national governments in the UK to maintain a register of deaf people.
This means that there are no accurate figures for the incidence of
deafness. However, local studies*
have produced figures which can then be used to give estimates of the number of
people affected in the general population. Scottish Deaf Population: Using estimates* of the general rates of incidence of deafness in the UK, it is possible to approximate the number of deaf people in Scotland as follows:
This would
suggest that one in seven of the total population is experiencing some degree of
hearing loss. Despite this,
deafness remains as one of the least understood and most ignored socio-medical
conditions in the country. * Estimates from Strathclyde Region Review of Services to Deaf People 1989, as applied to population figures for Scotland in 1991 census.
How
do deaf people communicate ? The means
of communication used by a deaf person often depends on their age when deafness
occurred, and on the degree of their deafness. People who
are hard of hearing or moderately deaf can generally benefit from modern hearing
aids, and are able to communicate normally without too much difficulty. People who
go severely or profoundly deaf during their life are generally still able to
speak and are literate. They
understand spoken language and so have a potential for learning to lip read.
They can follow sub-titles on TV and films, and can use text messaging on
their phones. However, they will be
unable to use radios or ordinary phones, and will not understand messages on
tannoy systems, etc. People who are born deaf or who become deaf in early childhood have great difficulty in learning to speak or to understand spoken language, and corresponding problems with literacy. Their most effective form of communication is through sign language, and they may have extreme difficulty with trying to lip read and with written material. Because of the lack of knowledge of sign language within the general population they often need the services of an interpreter to enable them to communicate meaningfully in open society.
Disability
is formally defined as “the loss or reduction in power of normal activity”.
In this sense, deafness could be reckoned to be a disability in that it
is the loss or reduction of the power of hearing.
However, there is also a personal element in the social definition of
disability because each individual has their own opinion about what they
experience and about how they cope with their condition.
People who
are born deaf are often otherwise fit and healthy. They have never experienced ‘hearing’ as a normal
activity and so are not so conscious of a loss or reduction in ability.
People who are born deaf, who form the majority of the sign language
community, often see themselves as part of a minority language group rather than
a disability group. People who go deaf during their lifetime are more likely to regard themselves as disabled because they will be conscious of having lost an ability which they were used to and which they used all the time. The more severe the deafness the more disabled they will feel.
What
is the “Deaf Community” ? The
“Deaf Community” is the term which is sometimes applied to the population of
deaf people who use sign language as their principal means of communication. The sign
language used by deaf people in the UK is known as British Sign Language (BSL).
In 2003 it was formally recognised by the British government as a
Minority Language, which gives it equal standing with Welsh and Gaelic.
BSL contains regional variations across the UK (akin to different
dialects in spoken language), and differs markedly from sign languages used by
deaf people in other countries. There are
reckoned to be between 50,000 to 60,000 people in the UK who use sign language
as their first or only language, with another 10,000 to 15,000 who use it as a
support (in Scotland the figures are estimated to be 5,000 primary users and
over 1,000 using it for support).* Sign
language users can often be very isolated within a hearing-orientated society,
where knowledge of sign language is minimal.
It has therefore been common for sign language users to meet together for
social and recreational activities, often in recognised Deaf Clubs or Societies.
A network of such groupings across the country forms the basis of a
recognised deaf community. Social
research has shown that this community, with its own language and customs has
its own recognisable culture. People who
go deaf during their lifetime generally continue to view themselves as part of
the majority hearing population, and so are much less likely to try to become
part of the deaf community. Relatively
few people who become deaf later in life feel the need to learn sign language,
preferring instead to rely on their knowledge of lip reading and the written
word. They will sometimes associate
together in Hard of Hearing Clubs or self-help groups, but these are seen as
being outwith the general deaf community. * Estimates
from British Deaf Association leaflet. ** Ladd, Alker et al, “Deaf Worlds” Vol 18 Issue 3 2002
How
do people who are both deaf and blind cope ? It is
estimated that in the UK there are between 20,000 to 25,000 people of all ages
who have significant problems with both sight and hearing
(approximately 1,800 in Scotland). Their
ability to cope with the dual sensory impairment depends on many factors, not
least of which is the stage in their lives that they became deafblind. People who
are born both deaf and blind will have extreme difficulty in developing any
communication and have a very limited experience of the world around them.
They will generally need a high level of care and support throughout
their life. Some
people are born deaf and go blind later in life.
They may have been dependant on sign language for their communication,
but this will become increasingly more difficult for them as they lose their
sight. People who
are born blind and then go deaf later in life will probably have acquired
knowledge of spoken language and may be able to read Braille or other
touch-sensitive print, which they can continue to utilise after they are deaf. People who are born with hearing and sight but then become deafblind will experience particular problems in losing many of their normal means of communication but will still be able to speak. They are very likely to experience a good deal of emotional turmoil due to losing two major senses.
How
do deaf people manage at work ? Research
has shown that the rate of
unemployment amongst deaf people in the UK is four times higher than for the whole population.
Deaf people who are in employment often tend to
be restricted to low paid, unskilled jobs, irrespective of their abilities. This has
often been due to a number of factors such as health and safety issues,
poor education and training opportunities and problems with
communication, but is exacerbated
by lack of understanding of deafness by managers and other workers. It is hoped that the Disability Discrimination Act may help deaf people to achieve their true potential in the fields of employment, by allowing them to challenge some of the myths and misconceptions about deafness.
Are deaf people more likely to have other physical or mental health problems ? This is an
area which is under-researched and for which there are no firm figures.
Deafness
at birth is often due to trauma or infection (e.g. rubella), which can also
result in other physical and mental problems.
It might therefore be assumed that there may be a higher incidence of
other disabilities within this group. There is
some evidence to suggest that there is higher incidence of mental health
problems amongst the population of deaf people than for the general population
as a whole.* However, this is
principally due to an increased propensity for deaf people to experience
depressive illnesses, which could in turn be linked with isolation and problems
with communication. There is
no evidence to suggest that there is a higher rate of psychotic illness amongst
deaf people than in the general population.*
However, it is recognised that deaf people with a mental health problem
are less likely to get appropriate diagnosis or treatment, because of lack of
specialist services. *
“Mental Health and Deafness” Hindley & Kitson 2000
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