Newsletter
1 - Published April 1997
Welcome
This
is a new Newsletter. It is an initiative of the ISA to enhance communication
on new developments within the Society and to realise co-operation in our
field and to realise an international voice of Audiology. It is the forum
where you, the members of the Society, can voice your concerns and report
your achievements. It is meant to realise what a society is, a symbiosis
of people with alike interests who like to share. Please, send in reports
to the Editor.
ISA in change
Hans Verschuure, secretary-general
ISA
The International Society of Audiology
was founded in the early 50s by a number of highly interested and motivated
researchers and clinicians. At that time the number of congresses organised
in the medical field was small and there was a definite need for exchange
of ideas. The ISA was founded in the way usual at that time: a meeting
place for interested individuals and with links to WHO in Geneva.
The structure of the ISA was made
accordingly.
The major activities of the organisation
over the years have been:
The organization
of biannual conferences held every even year
The publication
of a journal, Audiology
The field of audiology has developed
since then and we face an entirely different world now. The number of people
responsible for audiological services have grown from some hundred to many
thousands. There still is a need to expand the services because of noise
pollution and a population that is growing older. Furthermore the quality
of services to be provided is rapidly growing thanks to
new developments in amplification
and medical care. Still in many parts of the world, services are restricted
and often provided by people whose education in the field might be improved.
There has been a tendency for the
congresses to become more clinical, for the journal to become more basal.
Still the potential for participation in the conferences is much larger
than participation because quite often national and regional meetings are
considered more important. Also the potential for the journal does not
seem to be used to the full, clinical papers of good quality should be
submitted
more. Don't forget that the journal
"Audiology" has one of the highest impact rates in the field which makes
your publication count.
The globalisation of the world is
an important aspect of modern times. It does not mean that we should simply
adopt a model from a well-developed country; it means that we should listen
to each other and see what benefit we can get in one country from using
the experience in another country.
The provision of sufficient means
to cover the costs of services is a real problem all over the world. In
the developed countries the fast growing expenses of medical services require
containment, in the developing countries funds are very limited and should
be used carefully. The awareness of communication problems is not well
developed in society. Politicians seem not to recognise the importance
of hearing for the development of people and society and the general public
is often unaware of the impact of a hearing loss on their performance.
The medical profession tends to ignore it as it is no direct threat to
life. People seem not to understand its significance for the quality of
life, for the development of young children, for the participation (or
isolation) of old people in society. We need a voice to support national
and international initiatives to protect the quality of life.
The ISA has decided to change and
a couple of changes are now taking place. This very newsletter is the first
of its kind and will serve to provide information of what is happening
in the world of audiology to all members of the Society. Other changes
that have taken place are the reduction in the cost of Audiology and the
distribution of the Hearing International Newsletter to our membership.
Please note, that Audiology publishes papers on basic and clinical audiology.
Other
changes are that regional and national
societies can now become affiliated members and non-university trained
people working in audiology can become associated members. If you are interested,
please contact the secretariat by mail, fax, e-mail or on the web (www.eur.nl/fgg/kno/ACTIF/
isa.htm).
We feel that by making these changes
the ISA has become more attractive and appeals to the workers in the field
to make audiology a global experience. Read this newsletter just to give
you a taste of a global experience.
At the Bari congress in 1996 it
was decided to change the structure of the Society to bring it in a modern
shape. New forms of membership were opened to make the ISA the international
voice of Audiology. Some regional societies have expressed their interest
to join the ISA and to use its publications as their official organs. One
of the first to ask for affiliated membership was the PanAmerican Society
of Audiology. The Society presents itself in this paper of its President.
Report from the Americas
Sandy Gerber, Spokane, WA, USA,
President of PASA
Foundation
The PanAmerican Society of Audiology
(PASA) is one of the first regional professional societies of audiology.
It was founded during the International Congress of Audiology in Japan
in 1992.
Officers and Membership
The present officers of PASA are
Sanford E. Gerber (USA), president, Pedro Berruecos V. (Mexico), vice president
for North America; Fausto Coello-Serrano (Ecuador), vice president for
South America; George T. Mencher (Canada), treasurer; and Juan José
Madriz-Alfaro (Costa Rica), secretary. Any person who resides in any of
the 35 nations of the Americas may join PASA, but other people can become
associate members. To join PASA, send US$25.00 to the treasurer.
Everyone is welcome. Further forms
of membership of PASA is organizational memberships and corporate memberships.
So far only ASHA has joined PASA.
Activities
PASA meets
every two years, in odd-numbered years to avoid conflicting with
the international congresses.
PASA publishes
a quarterly newsletter called appropriately, "¿QUE
PASA?"
The editor of "¿QUE PASA?" is Dra. Monica Lopez-Vasquez of
Mexico. The newsletter prints a calendar of audiological meetings and events
in the Americas and a section of audiology news of the Americas. In addition,
it carries a regular news item from the president and a comment from
the editor.
At the
biennial meetings, the distinguished PASA lecture is given. The first
PASA lecturer was Prof. Dr. Jorge A. Schwartzman of Argentina, the second
was Dr. Pedro Berruecos V of Mexico. At the 1997 meeting, we are
honored to present our third distinguished PASA lecturer, Dr. Ross
Roeser of the University of Texas at Dallas and the Callier Center.
Future Activities
The next
meeting will be in conjunction with the annual meeting of the American
Academy of Audiology. It will be held in Fort Lauderdale, Florida on the
16th of April, the day before the AAA meeting starts. Our agenda will consist
of the required business meeting, including election of officers, and the
PASA lecture. Every one is invited. PASA is especially happy
to note that the next International Congress of Audiology will be
held in our region, in Argentina in 1998. Of the (then) 24 congresses,
only four have been held in the Americas. We have tentative plans to present
a PASA-sponsored pre-congress meeting in Quito, Ecuador. More about
that as plans materialize.
We invite your membership.
For information about PASA, please
contact the secretary:
Dr. Juan José Madriz-Alfaro
Apdo. 223 - Centro Colon
San Jose 1007, COSTA RICA
Another region of the world with
a regional Society is Europe. Its regional society (or federation of societies)
seeks co-operation and affiliated status with the ISA.
Report from Europe
Jonathan Hazell, London, UK,
Secretary of EFAS and Stig Arlinger,
Linköping, Sweden, President
EFAS
Foundation
A preliminary meeting to found an
European Organisation was held at the Congress of the International Society
of Audiology in Tenerife in 1990. It was decided to form a working group
and to organise a meeting. The European Federation of Audiology Societies
was founded in 1992 at the first European Conference on Audiology hosted
by the British Society of Audiology in Cambridge, UK.
Aim
The aim of EFAS is to promote co-operation
between national organisations for audiology, in the same spirit as today's
audiology is based on a co-operation between several professional groups.
Officers and membership
The members of the EFAS can only
be national Audiology Societies or in case there is no national Audiology
Society persons or representatives of professional organisations that can
be considered representative of audiology in that country. Each country
is represented in the General Assembly by one voting member and
two non-voting members. The first
meeting of the General Assembly took place in Hanover, Germany in 1993
where a provisional board was formed. This council was duly elected at
the second EFAS congress, held in Noordwijkerhout, the Netherlands in 1995.
The present council of EFAS consists of Stig Arlinger (Sweden), president;
Jonathan Hazell (UK), secretary and treasurer; Rene
Dauman (France), president-elect;
Jarka Prihodova (Czech Republic), simulated past-president; Hans Verschuure
(Netherlands), member-at-large. At Present there are 29 countries represented
in EFAS.
Communication between the secretariat
and the membership in 29 countries in and around Europe is done almost
exclusively by e-mail. A website (currently accessible through www.tinnitus.org)
provides information about our aims, representatives and European conferences
arranged by the member counties in association with EFAS.
Activities
Audiology
has not been well-established in Europe and differences between the
countries are enormous. The first goal will be to make an inventory of
available services and the training of the people providing the services.
The process was started in 1993 and is still pursued. Provision
of help where it is needed and requested for training in Audiology.
Last year the first European Audiology course took place financed by the
EU Tempus programme and some European industries. Pupils came from Romania,
and the Czech and Slovak republics and received training from selected
teachers in six leading European clinics. They returned to their own countries
to set up local teaching programmes. As a second phase of that Romania
is now running a first training course ever for audiology assistants with
20 students coming from all over the country. EFAS has a role in
representing the view and needs of member counties through their
national societies, and since its inception has prompted the formation
of 7 national societies where before there was none. This helps
not only in a European programme
of advancement, but also nurtures
academic audiology and encourages
high standards of audiological practice and hearing health care in each
country. It is essential that the national societies take an active interest
in EFAS deliberations at their yearly general assemblies, held at
EFAS or ISA conferences.
The organization of biannual European
conferences in the odd years when there is no international congress.
Past congresses took place in Cambridge and Noordwijkerhout. EFAS
takes great care to liase and interface with ISA, Hearing International
and other regional organizations where appropriate. Several representatives
and officers have dual roles which facilitates this process.
Future activities
The next
meeting will be held in Prague, 18-21 June, 1997. Information can be obtained
from the Secretariat of the 3rd EFAS conference, Dept. of Paediatric Otolaryngology,
Faculty Hospital Motol, V. Uvalu 84, 18 Prague 5, Czech Republic, Fax.nr.
+42 2 2443 2620. The meeting after that will take place in
Oulu, Finland in 1999, organised by Prof. Martti Sorri Make
an inventory of training and education of service providers in Europe.
Establish minimum requirements for service providers to guarantee quality
and make the exchange over national borders possible. Promote audiology
and hearing care with the European Commission and with national governments.
We are a young organisation but
one with a bright future, and we are fulfilling a definite need within
Europe.
Further information on the EFAS
can be obtained from the secretary:
Dr J W P Hazell
RNID Medical Research Unit
3rd Floor Middlesex Hospital Annexe
Cleveland Street
London W1P 5FD, UK
Tel: +44 171 380 9308
Fax: +44 171 580 6726
email jon.hazell@ucl.ac.uk
Oto-acoustic emissions have become
an important issue in Audiology. Its implications for hearing science have
been studied quite extensively and are not fully understood. Its clinical
application is gaining interest. One of the clinical researchers of tot-acoustic
emissions, Dr. Bert van Zanten, presents a survey of the subject.
Oto-Acoustic Emissions
Bert G.A. van Zanten, PhD (clinical-physicist/Audiologist),
Hearing & Speech - Centre, Sophia Children's Hospital, Erasmus University
Medical Centre Rotterdam, the Netherlands
Introduction:
The discovery of the phenomenon of Oto-Acoustic Emissions,
OAEs, by Kemp in 1978 has lead to tremendous developments
both in basic auditory research and in health-care applications.
Kemp already indicated in his paper the clinical potential of the
phenomenon. Although Kemp's basic finding was repeated
within one year by others, the acceptance of the clinical potential of
the OAE-phenomenon grew rather slowly. The recording of the OAE phenomenon
(originally called the Evoked Cochlear Mechanical Response) requires the
use of a sealed probe in the ear canal. The probe contains a telephone
and a microphone. A click is presented through the telephone. The microphone
now records the sound in the ear canal consisting of the stimulus and a
reproducible sound wave.
The two panels of the figure show
an example of the recording from the microphone. Both panels show the sound
pressure amplitude as a function of time. The panel to the left shows the
waveform of the stimulus, which last only a couple of ms and the panel
underneath show the signal recorded up to 20 ms after the start of the
stimulus. Please, mind the large difference between the amplitude scales
being almost three orders of magnitude.
It has been shown in the literature
that this signal is generated in the cochlea, transferred through the middle
ear and radiated into the ear canal by the tympanic membrane acting like
the diaphragm of a loudspeaker. All kinds of lesions to the cochlea make
the OAE phenomenon disappear or change, such as a noise trauma, the ototoxic
effect of a drug, asphyxia, and others. When the inner
ear function is abnormal and pure-tone
audiometry shows a hearing loss of more than 20-30 dB at all frequencies,
the OAE can not be recorded anymore as a response to click-stimulation.
It is important to keep in mind
that the middle ear is the channel transferring this weak sound from the
source in the inner ear to the recording system in the outer ear canal.
The OAE in normal adult ears is rather weak, on average about 10 dB SPL.
Small losses caused by minor middle abnormalities can cause the OAE to
be too weak to be recorded.
In summary, the click-evoked OAE
is a weak sound generated by the cochlea. It is only present if the cochlea
shows no significant sensitivity loss and if the middle ear is normal.
Only one exception to this rule has been reported up to now. In a hydroptic
cochlea, such as in Meniere's disease, the OAE can be present in spite
of cochlear losses of up to 60 dB measured with pure tone audiometry.
Other types of OAEs have been recorded
since 1978. Two main classes are known, the spontaneous oto-acoustic emissions
(SOAE) and the evoked oto-acoustic emissions (EOAE). SOAEs are generated
in the cochlea without external stimulation. They usually are stable over
time and they are continuously present. The Evoked OAEs, EOAEs, are generated
in the cochlea as a response to external sounds. It usually is not easy
to differentiate between the stimulus and
the cochlear response because of
the large level difference. This is done presently either in time or in
frequency. Transiently evoked OAEs, TEOAEs, are elicited by very short
stimuli. The weak response is recorded separately after the end of the
strong stimulus. Kemp's original recordings were made after the shortest
stimulus possible, the click, had ended. Distortion product OAEs, DPOAEs,
are pure tones
generated in response to two externally
presented pure tones under certain conditions. They are generated as distortion
products by the cochlear mechanism when processing these pure tones. The
distortion products can also be heard and are called cubic difference tones.
Research applications
The OAE-phenomenon was totally at
odds with the current theories in 1978 on cochlear mechanics. Many researchers
and clinicians found it unbelievable that the ear would generate sounds.
This is one of the reasons for the slow start of research on the clinical
application of OAEs. The auditory theory had to be modified first into
the concept of an 'active' cochlea, generating OAEs. Presently, OAEs are
viewed as the by-products of cochlear amplification of weak sounds in order
to make them detectable for the mechano-neural transducer. In this concept
the outer hair cells (OHCs) amplify sounds of levels of roughly 0 to 60
dB SPL. The inner hair cells (IHCs) function as transducers for sounds
with levels of between 60 and 120 dB SPL. The range of the IHCs is extended
downward by 60 dB through the OHC mechanism. More basic research is still
needed to find out the details of the transduction and the amplification
mechanism. OAEs can be
modified by contra-lateral stimulation.
This enables non-destructive assessment of the central control of the inner
ear by the efferent fibres of the acoustic nerve.
Clinical applications
The OAEs are usually weak sounds
which means that confounding sounds are easily picked up by a sound recording
system. In fact it is much easier to make a sound recording system that
oscillates in response to a stimulus than it is to make a reliable OAE-recording
system. The first commercially available systems were unreliable when used
in clinical conditions. As a result people lost confidence in
the use of OAE recordings for clinical
purposes. Furthermore a patent on OAE recordings was filed in a number
of significant countries which allowed the patent holders to fully control
further commercial developments. As a consequence commercial developments
were hampered. Kemp's view that he could better 'publish' significant parts
of his lab's knowledge on methods of reliable OAE-recording in the form
of equipment lead to the OtoDynamics company, presently dominating the
world market of OAE recording equipment.
(Remark by author: I'm not in favour
of a 'pharmaceutical' approach to scientific knowledge, but in this case
I'm not so sure that it was wrong. It appears that most of the developments
done or supported by OtoDynamics would not have been done at all or else
much later.)
Presently the major clinical application
of OAE recording is the screen for ear-dysfunction in all neonates or in
targeted groups of neonates. This development was started around 1989 and
is growing rapidly. In the US the number of neonates screened almost doubles
every year and was over 120,000 in 1995. Half of the screens were done
by proving OAE presence, the other half by auditory-brainstem-response
screens. In a recent report by the EU concerted action programme, an inventory
of European sites of neonatal hearing screens was made. It showed a rapid
growth in Europe too, although Europe still lags behind the US. In the
north-western European countries there was a tradition of behavioural hearing
screens; here only studies on the feasibility and the efficacy of neonatal
screens by OAEs have been done or are presently being done. In countries
that lack an universal screen the decision to screen neonates universally
has been made or is about to be made. The decision to use OAE recordings
for neonatal screens has been taken in a number op eastern European countries.
OAEs can also be used for the discrimination
between cochlear and
retro-cochlear pathology. The OAEs
are in fact purely a cochlear phenomenon. Their presence is hardly influenced
by retro-cochlear dysfunction. In a case of a neural hearing disorder the
presence of an OAE can proof the (almost) normal function of the peripheral
ears although the audiogram is abnormal. This is important knowledge for
hearing rehabilitation and for the planning of surgical intervention in
cases of cerebello-pontine angle tumours.
At the Santa Barbara Congress in
1984 it was decided to support initiatives to establish ear and hear services
in the developing world. The decision to do so was taken after an appeal
by Sir John Wilson. This initiative has led to co-operation with the International
Federation of Otolaryngology Societies, IFOS and the eventual founding
of Hearing International. One of the first initiative to be established
was a Centre in Bangkok for the prevention of deafness. Here you find two
reports on this activity supported by ISA. Other
reports can also be found in the
Hearing International newsletter.
Report From Asia
News from the Otological Centre,
the Bangkok Unit of the Faculty of Medicine Siriraj Hospital
Dr. Suchitra Prassansuk, Director
Structure
The Otological Centre, the Bangkok
Unit was established on 12th March 1985 as first ISA-IFOS Centre for the
prevention of hearing impairment and deafness. It has become the first
WHO collaborating centre in July 1988. It is situated at the ENT Department
of the Faculty of Medicine of the Siriraj Hospital of Mahidol University
and is under the directorship of Dr. Suchitra Prassansuk. The purpose of
stablishing the centre was to realise the initiative taken by ISA and IFOS
for a global campaign on ear and hearing care.
WHO requirements
The centre is a WHO centre for which
it has to fulfil certain criteria, called the terms of reference. These
are:
1.to provide courses
to upgrade the audiological capabilities of ENT doctors within the region.
1.to disseminate ENT technology of specialists and non-specialist
hospitals and personnel, as well as at the level of primary health
care.
2.to act as a referral
centre for patients with known or suspected auditory disabilities, particularly
when there is uncertainty of diagnosis or problems in management.
3.to provide or advise
on suitable medical, surgical and rehabilitative
management
of patients with auditory disorders.
4.to construct a data
base on the nature and extent of auditory disorders in the region.
5.to formulate prescriptive
screening programmes within the context of various regional countries.
6.to advise governments
in the region on prevention programmes for auditory disability appropriate
to the structure in these countries.
7.to undertake research
into how essential ear care can best be socially and cost-effectively
provided at community and district health levels.
8.to collaborate in
the regional Fellowship programme in graduate and post graduate ENT specialist
training.
Achievements
The Otological
Centre, the Bangkok Unit has already accomplished 11 successful Oto-audiology
Update Courses with almost 500 participants from over 20 countries.
Survey
and Service for ear and hear care were done through out Thailand.
Manpower
development and service have been extended to neighbouring countries
in greater need such as Laos, Myanmar, Mongolia.
The Otological
Centre, Bangkok Unit has been a centre of excellence and has helped
in establishing other centres in the region in Jakarta and Manila.
The report shows the good outcome
of the initiative in that in the some 10 years after starting the work
ear and hear care has been established in ASIAN Countries and has flourished.
It shows that a network can be set up in the area and that co-operation
can be established to the advantage of all countries.
Another such an initiative took
place in Mexico City, on which its director now reports.
Report from Mexico
Prof. Dr. Pedro Berruecos, President
of the IMAL
THE MEXICAN/Latin-American MODEL
FOR THE TRAINING OF
SPECIALISTS IN THE AUDIOLOGICAL
FIELD: Graduate and Postgraduate Programs.
The Mexican Institute of Hearing
and Speech-Language (IMAL), is a non government, non profit organization,
first of its kind in Latin America, and was founded in 1951. Since 1995,
IMAL has been nominated as one of the 11 Affiliated Centers of IFOS/ISA/HI.
Medical Doctors, Speech and Language Therapists, Teachers for the Deaf
and Technicians in audiometry, have been trained at the IMAL since the
50s and have taken part in the establishment or in the reinforcement of
an important number of institutions all over Mexico and Latin America.
The first Mexican specialists were trained at the IMAL and they inaugurated
the Mexican Society and the Mexican Board of Audiology and Phoniatrics,
20 and 10 years ago, respectively. The Mexican Society today has more than
500 members and the Mexican Board has certified more than 200 Medical Doctors
specialized in Audiology.
After the experiences over 45 years
in the training of personnel in the audiological field, the IMAL is now
working in 4 main programs:
Training
of technicians in audiometry and auditory rehabilitation
It is a two-year training program
for technicians who will be in charge of the diagnostic and therapeutic
electro-acoustic equipment in the clinical setting and who will fit hearing
aids. The training incorporates ear mold production, lip reading and auditory
training
A graduate
program for speech and language therapists and teachers for the deaf
It is a four-year training program
and graduation permits their professional involvement in rehabilitation
clinics or in special education settings
A medical
specialization in audiology and phoniatrics
It is a three-year program for MDs,
conducted on the basis of an agreement with our biggest medical center,
the General Hospital of Mexico, with the academic approval of the National
University of Mexico
A master
degree in hearing, speech and language pathology
This is the first postgraduate program
of its kind in Latin America. Its main objective is to train high-level
professors and researchers in the fields
All IMAL programs received the official
approval of the Department of Higher Studies and Scientific Research of
the Ministry of Education of Mexico.
The program brings IMAL in a privileged
position to improve the quality of diagnosis and therapy in the field of
audiology, catering for the needs of a 450 million population in the Spanish
speaking countries. IMAL´s main objectives are also aiming at a spin
off: an improvement of the academic and professional standards of our disciplines
all over the Latin-American region.
The next congress of the ISA will
take place in Buenos Aires, Argentina. We received the following report
from the organiser
XXIV INTERNATIONAL CONGRESS OF
AUDIOLOGY
Dr. Jorge Schwartzman, President
XXIV Congress ISA
Focus of congress
We would like this Congress to be
an opportunity to integrate audiologists from Latin-American, which due
to economic reasons cannot often afford to travel, with audiologists from
Europe and the USA. Of the vast amount of American audiologists only a
very few take part in these international events, while others tend to
attend only national conventions. We would be very pleased of this event
could be a way of integrating colleagues from all over the world in a meeting
where we can share our experiences, research and knowledge. At this moment,
entering the third millennium, with the special characteristic that everything
goes global, let us hope that this event be a way to globalisation of audiology.
Hot topics like effects of drugs and surgery on the treatment of hearing
loss, regeneration and plasticity of hearing cells, re-engineering of auditory
pathways, cochlear implants, oto-acoustic emissions, and others will be
discussed by the most prominent specialists of this field. Apart from this
primary goal of the congress, the congress and its venue have more to offer.
Argentina
It is located at the Southern extreme
of the American continent. Argentina is the eighth largest country of the
word and, I can assure you, one of the most beautiful countries. It is
a place to enjoy for all four seasons and you can see every type of scenery
imaginable. Each region of the country offers something different because
Argentina contains areas with all physical conditions known to man: heat,
cold,
forest, desert, mountains, endless
plains and big cities.
Buenos Aires:
The town is built along the Rio
de la Plata. It is the most elegant city of South America. It is a booming
capital by day and ablaze with entertainment by night. Doted with luxurious
palaces and modern buildings, Buenos Aires is one of the most fascinating
cities in the world. It is a city where the traveller yields to the charm
of the Tango. Theatres and museums, parks and boulevards, shops and hotels,
and a wide choice of restaurants in which one can sample the word-famous
Argentinean beef. For the European, Buenos Aires is the cosmopolitan city
given to the outdoors, with unique hospitality, cultural activity and charm.
