Surveys on Hearing Loss around the World and Their Uses
By: Andrew Smith, Hannah Ayukawa, Ian Mackenzie, &Valerie Newton
The experience of deaf and hearing impaired persons varies widely depending on the services
available in their home country. The workshop has two objectives. One is to inform the public
about the challenges facing the hearing impaired and deaf in different and diverse regions of the
world. The second objective is for professionals to learn how and why hearing and ear surveys
are carried out and how the results can help in defining solutions. To achieve these two goals,
some recent WHO survey results will be presented by panellists who are or were working in
Asia, Africa, Europe and America. Similarities and differences in the provision of services,
types of rehabilitation available and efforts in prevention of hearing loss are some of the issues to
be addressed.
HANNAH AYUKAWA
WHO Hearing Survey in Canadian Inuit
Outline:
- Description Nunavik
- Particular challenges
- Hearing problems
- What was done before the survey
- Description of survey
- Why do a survey?
- Results
- What did we learn?
- What has happened after?
Particular challenges in Nunavik
Nunavik is the northernmost region of Quebec.
In 2001 census, there were 9632 inhabitants and 91% were Inuit.
14 villages connected by air; high cost of travel, 1 or 2 visits per year
Hearing problems in Inuit
Inuit have more hearing problems than First Nations.
There is a high prevalence of hearing loss due to the highest rates of chronic suppurative otitis
media in the world. This is a “new” disease that arrived in the north since contact with the south
in 1960s.
85% of Inuit children have 3 episodes of otitis media before age one. Rather than middle ear
fluid causing hearing loss, more often the eardrum will perforate and about 20% of kindergarten
children have a hearing loss.
What was done before the survey?
Travelling audiology services for the past 20 years with the collaboration of Inuit hearing
technicians in the communities
All school children assessed, day care screening offered, also adults seen on referral
Provision of individual hearing aids for adults and children
Promotion of classroom amplification
Prevention of hearing loss due to otitis media through education, vaccination
Why do a survey?
In 1992 the Nunavik Health Survey found that hearing loss was the most common chronic health
problem reported. Twelve percent of adults reported hearing problems on a questionnaire.
In comparison with the rest of Canada, the Canadian Community Health Survey, 2003, found
that 3% of persons older than twelve years reported hearing loss.
“Are you usually able to hear what is said in a group conversation with at least three other people
without a hearing aid?”
Self-reported hearing loss is difficult to compare because of the lack of standardisation.
However, it can be seen Inuit suffer significantly more hearing loss compared to Canadians in
general, but how much more?
Description of survey
Qanuippitaa : The Canadian icebreaker Admundsen travelled to the 14 villages to conduct a
wide-ranging health survey. Information was obtained by clinical tests, questionnaires and
interviews .which included social and lifestyle factors, and mental and physical health indicators.
Random sampling of households in which there was at least one Inuit over 18 years old was
done.
To compare with the rest of the world, decided to use modified WHO survey. We Used the
WHO ear and hearing protocol. The hearing tests were done on the boat; we did not do the “ear
part”, and we tested only 1k, 2k, 4k Hz, stopping at 20 dBHL if a response was present.
Results of the survey:
821 hearing tests of adults 18 years and older
Hearing loss (age 18-74 years)
Normal, Normal
Normal, Mild or worse
Mild, Mild or worse
Moderate, Moderate or worse
Both sexes
56.0
19.3
17.2
7.6
Women
66.7
20.8
12.5
Only 56% of the population surveyed has normal hearing in both ears.
Three times more men than women have hearing loss in both ears.
Men
45.6
17.8
36.6
Hearing loss (>25dB average in both ears) according to age group and sex
Age group
Both sexes
Women
18-29y
8.1
5.4
30-44 years
22.2
8.4
45 and up
51.1
27.1
Men
10.7
35.6
75.5
Men who hunted more frequently had more hearing loss.
Secondary school graduates had better hearing than those who did not complete secondary.
Nunavik
WHO Hearing impairment
> 26 dB in better ear
24.9
Disabling hearing impairment
>41 dB in better ear
7.6
The prevalence of hearing loss is similar to that measured in parts of the developing world.
What did we learn?
Adults, especially adult men need to be seen for assessment and counselling
Need to make people aware of the dangers of noise
Need to find acceptable ear protection and make it available locally
What has happened since?
-
Workshop on noise 2005: invited lecturer Ravi Sockalingam from Dalhousie University
Attended by Inuit hearing technicians.
-
Conducted a survey of community members about noisy activities, measured noise levels
in the community, tested different types of ear protection
-
Articles in newspaper and magazine (delivered to all homes)
-
Classroom presentations to secondary students in some communities, and to be continued
-
Changing focus to see older adults (over 50 years) for hearing tests, also asking
employers to see workers exposed to noise (e.g. heavy equipment operators): resulted in
more adults seen and opportunities for counselling
-
Standard earmuffs and earplugs already available locally. Working to improve
accessibility of “high tech” ear protection. Now available in some communities at
subsidised prices via special program for hunters. Still working to get regional access.
VALERIE NEWTON
Surveys from China and Kenya will be used to demonstrate how simple questionnaires, used to
detect hearing loss in infants and young children, can provide benefits for the community in
which they are carried out.
Points to be covered
- Hearing loss can be detected without the need to purchase expensive equipment.
- Detection of hearing loss that would not otherwise be found
- Infants and children habilitated who would not otherwise have been helped
- Professionals and parents made aware of the signs of hearing impairment in infants and
young children
- Awareness created amongst parents and teachers of the needs of hearing impaired
children at home and at school
- Creation of interest to have other children tested
- Knowledge of the causes of hearing loss spread and means of prevention indicated
- The problems of schooling highlighted
- In some children hearing loss was eliminated as a cause of poor communication,
indicating that other causes should be explored.
- Highlighted the needs for better services and more trained personnel.
IAN MACKENZIE
The results of surveys of hearing loss in Oldham, UK and Peshawar, Pakistan, are used to show
the contribution of consanguinity to severe/profound deafness. Quoting the work of Zakzouk in
children, the problems of deafness in a particular ethnic community are discussed. The work in
Saudi Arabia on deafness as a disability has led to a planned program to reduce deafness and
discourage consanguinity. Methods of alerting the ethnic population to deafness will be
described.
ANDREW SMITH
This presentation will first briefly overview the size and nature of the challenges facing hard of
hearing & deaf persons around the world. One of the ways to gather information about these
challenges and empower communities to address them, is through conducting population-based
surveys of prevalence, causes and needs for hearing loss. The WHO Ear and Hearing Disorder
Survey protocol was devised to enable countries to conduct such surveys. Its rationale, methods,
intended outcomes and benefits will be described, and illustrated using surveys that have been
carried out in several developing countries.
Points to be covered
- The effects of hearing loss on individuals and societies
- Recent information from WHO on the size and nature of the burden of hearing loss
- Comparison of the burden with other disabling conditions, and of interventions against
them
-
Why the WHO survey protocol is needed
Purpose, principles and methodology of the protocol
Outcomes and benefits of the protocol with illustrations from recent surveys in Africa,
Asia and Latin America.