|
28/12 |
- Due to the New Year Festivities (and the relative holidays)
the OAE Portal pages will not be updated until January
8th 2005.
|
|
23/12 |
- The white paper section on neonatal
screening was updated with a contribution from Dr. Enrique
Dal Monte titled "Hearing Loss Screening In Newborns
And Infants In Paysandu, Uruguay". Dr. Dal Monte has
provided additional material for the screening
practices in Uruguay , from his Powerpoint presentation during
the 2003 IFOS meeting at Cairo Egypt. The extra
material is available on-line as a PDF
file (2200 k).
|
|
21/12 |
- Audiology Today (November - December
2004 issue, page 46) ran a short review-announcement on the OAE
Portal , which you can access on line.
|
|
17/12 |
- The on-line powerpoint
presentations (clinical
section) was updated with a contribution from Dr. Michael
Gorga titled "DPOAE Suppression Tuning Curves
in Normal and Impaired Human Ears". The material is derived
from two JASA 2004 publications which the author
made also available to interested readers.
|
|
05/12 |
- The Recent OAE
articles section was updated with Volumes 4-5-6
(the last three for year 2004).
- The Italian
Authoring Activities page was also updated with contribution
from the Rome ISPESL group titled Objective
estimates of cochlear tuning by otoacoustic emission analysis.
The article appeared in J Acoust Soc Am. 2003 Jan;113(1):423-9
|
|
01/12 |
- The future highlights
section was updated with material which will be presented until
April 2005.
|
|
30/11 |
|
|
24/11 |
- A interesting course on "How to Identify and Manage
How to Identify and Manage Patients with Patients with Auditory
Neuropathy/ Auditory Neuropathy/ Auditory Auditory Dys-Synchrony
" has been advertised by the Kresge Hearing Research
Laboratory Continuing Education in New Orleans. The course will
take place on February 17-19 2005 . You can download
the relative brochure from here (pdf
file 1.8 M) or contact directly the Kresge
web site.
|
|
18/11 |
|
|
09/11 |
- A new addition in the section of on-line lectures
(biophysics) is now
available. The lecture by Dr. Stavros Hatzopoulos
is titled "Impact
of Otoacoustic Emissions technologies to Audiology and Hearing
Science" and represents a combination of information presented
in numerous invited lectures in 2003-2004. The material is available
as a color pdf file (4160 k) and requires 8
min of downloading time. Users who have slow modem connections
can request
to receive the file as an email attachment (assuming that they
have no space limitations in their mailboxes)
|
|
02/11 |
- The first statistics for the month of October 2004 are
signalling an important event for the life of
the Portal. For the first time after two and
half years of cybernetic existence the number of visitors has
surpassed the 10,000 limit (10820 to be exact).
- We believe that this high number of visitors reflects
the need for free and reliable
OAE information around the globe and it is rewarding to see that
the International OAE community appreciates our
efforts.
|
|
29/10 |
- As it was announced a few weeks earlier the material
from the round table on NHS and telated technologies
(ISA meeting, Phoenix Arizona, September 2004) is now available
on-line as pdf documents. The following lectures
have been added to the NHS Portal
pages.
- A report from Brazil
(1.9 M): Dr. Katia De Almeida
- A report from Hong
-Kong and Austalia (716 K) : Dr. Bradley McPherson
- A report from a number of mediterrean countries -
Cyprus, Greece. Italy,
Portugal Turkey- (848 k): Dr. Stavros Hatzopoulos.
- A report from Mexico
(148 K) : Dr. Pedro Berruecos
- A report from the Netherlands
(836 K): Dr. Bert van Zanten
- A report from Poland
(860 K) : Dr. Marzanna Radziszewska-Konopka
- A report on the employed technologies
in NHS/ UNHS / EHDI programs (748): Dr. Stavros
Hatzopoulos
- A report on the use of
ASSR in NHS programs (76 K): Dr. Barbara Cone-Wesson
NOTE : If you don't have the Pdf
Adobe Acrobat reader you can download it from here
(approximatelly 6 M).
|
|
16/10 |
- An interesting twist in the arena of OAE and
AABR equipment. Natus
Medical Incorporated announced (on 29/09)
the acquisition for cash of privately held Fischer-Zoth
GmbH, a leading manufacturer of otoacoustic emissions (OAE) products.
The acquisition adds to Natus' growth opportunities by broadening
its product offerings and supporting expansion into new markets.
To read the rest of the press release click here.
|
|
10/10 |
- One of the main objectives of
the Portal is to provide FREE information to all classes of the
OAE community, and therefore it is absolutely mandatory
to create various collaboration schemes with the greatest number
of interested members of the community.
One way to tackle this issue is with the exchange of information
in the OAE FORUM which is still in the works
(delayed by software issues related to the server of University
of Ferrara). Another way, proved vey succesful so far
, is to offer membership to the Editoriar Board of internationally
known colleagues who can help us locally ( within their country
territory) and internationally (as members of the OAE board).
In this context, we are very pleased to announce the addition
of three new members to the OAE editorial board: Dr. Pedro
Berruecos (Mexico); Dr. Marzanna Radziszewska-Konopka
(Poland) ; and Dr. Joseph Pytel (Hungary).
- Dr. Pedro Berruecos received his degree
in Medicine from the Universit? Nazionale del Messico (1966) He
continued his studies with post-graduation work in Ferrara University
and University of Bordeaux (1968-1970). He is a member of the
Accademia Nazionale de Medicina del Messico (1982), has been the
founder (1977) and president (1979-1981) of the Mexican
Society of Audilogy and Speech Therapy, the president
of the International Society of Audiology (1984-86
e 1986-88) and president of the Societa Panamericana di Audiologia
(2001- . He is a Professor in Audiology and Speech
Therapy , Facolta di Medicina, Universita Nazionale del Messico
(1990- ) and head of the Audiology Department,
Ospedale Generale del Messico.
- Dr. Marzanna Radziszewska-Konopka graduated
from the Medical Academy, Bialystok (Poland) in 1986. She received
her doctoral degree in 2003. Her dissertation work was focused
on hearing aid fitting in infants. She is currently the Head
of Audiology, Phoniatrics and Laryngology, Department
in the biggest pediatric hospital in Poland, The Children's Memorial
Health Institute in Warsaw. In 2001 she was asked
to provide expert consultation to the Great Orchestra of Christmas
Charity with respect to their newborn hearing screening initiative
and in 2002 she was appointed as the medical
coordinator of the national Universal Newborn
Hearing Screening Program in Poland. She is responsible
for supervision over personnel training and the program quality
including the performance improvement at hospitals, referral centers,
and diagnostic programs.
- Dr. Joseph Pytel is the director
of the ENT Department of the Medical School of University, P?cs
(1994- to date). From 2000 to 2002 he has been the president
of the Hungarian ENT Society and from 1994-1998 the President
of the Hungarian Audiological Society. He is a Member of the Complex
Acoustical Committee of the Hungarian Scientific Academy, a Member
of the Editorial Board of American Journal of Otology (AJO), a
Voting National Representative of EFAS Executive Committee (European
Federation of Audiological Societies) and the 2002 Honorary member
of the Czech ORL Society and Slovak ORL Society.
|
|
03/10 |
- As it was announced last month during the meeting
of the International Society of Audiology (ISA)
at Phoenix Arizona, several members of the OAE Portal participated
in a round table titled "Neonatal Hearing Screening Models
outside the US: Protocols and Technology Updates. The
Round table was moderated by Dr. Stavros Hatzopoulos,
ran for 90 min and included the following 3 main sessions:
- The first session titled "The Past and
the Present" was dedicated to the UNHS/ NHS status
of numerous programs around the globe. The data presented
at this session suggested that despite the growing
numbers of NHS programs in the world, problems associated
with intervention policies STILL remain unresolved.
Contributions in this section included : (1) Data from Australia
and Hong-Kong (Dr. Bradley Mcpherson);
(2) Data from Brazil (Dr. Katia De
Almeida); (3) Data from the Mediterranean
Zone (Dr. Stavros Hatzopoulos);
(4) Data from Mexico (Dr. Pedro Perruecos);
(5) Data from the Netherlands (Dr. Bert
van Zanten) ; and (6) Data from Poland
(Dr. Marzanna Radziszewska-Konopka ).
- The second session was titled "Technology
Updates" and addressed the available tools for NHS
today. Dr. Hatzopoulos presented data on
the standard (A-OAE and A-ABR) and on new emerging techniques
(Cochlea-Scan) and Dr. Barbara Cone-Wesson
presented data on the ASSR involvement in UNHS/ NHS screening
policies.
- The last session was titled "Solution to NHS problems"
and included contributions from all the panelists to the NHS
areas where each one considered as problematic.
The presentations of the round table will be available on-line
from the third week of this month and they will
be placed in the neonatal screening
pages of the Portal.
|
|
20/09 |
- As it was announced earlier in the Portal, we have
considered very important to update the material related to the
generation mechanics of both TEOAEs and DPOAEs.
Dr. Christopher Shera has generously provided
a white paper
on his comments on the Dr. Renato Nobili's model
advertised in the Portal early
this year. In order to provide to our readers the "whole
scenario" the original references of Dr. Nobili's work (
book-chapter,
JARO
paper) are also available as pdf files.
- The Audiology Dept of Ferrara, Italy has announced
the second Italian course on Otoacoustic Emissions
in the context of the continuing lecture series on advanced
Audiology (FESPA).
The course will be given on October 21-22, 2004.
Interested parties can download the program of the course clicking
here
(material in Italian only!!).
|
|
14/09 |
- Dr. Christie Yoshinaga-Itano has accepted to
coordinate and enhance the pages related to Neonatal
hearing screening. Christie is a well known authority in this
area and the Portal will benefit not only from her personal experience,
but also from the information she has about various screening
programs in the World. Christie has been lecturing recently to
Australia and her report about the Australian continent will appear
in the World Program
Screening Projects, in October 2004.
|
|
10/09 |
- The January
2004 editorial presented material from Dr. Thomas
Janssen regarding the possible threshold prediction by
DPOAE IO functions. This argument has become the topic of many
additional investigations and one of the groups who has conducted
similar studies belongs to Dr. Michael Gorga.
His work on the DPOAE threshold prediction will be presented in
the months of September and October 2004.
The first two
powerpoint lectures (i) DPOAE
I/O Functions in Normal and Impaired Human Ears and (ii) Predicting
behavioral Thresholds From DPOAE I/O Functions refer to summaries
from papers presented in JASA. The You can download the material
from the Powerpoint Lectures, in the
clinical section . The powerpoint lectures are provided as
pdf files and require a pdf reader
( free download 6.2 M from Adobe).
In addition to the powerpoint material Dr. Gorga has generously
provided reprints ( pdf format) of the original JASA
papers which readers can also download .
|
|
05/09 |
- We have started initial tests with the forthcoming FORUM
pages. If the security tests conclude well the FORUM will open
around the 15th of October.
|
|
02/09 |
- The future highlights
section was updated with material which will be presented until
April 2005.
|
|
01/09 |
- Interacoustics (see their sponsored
Portal pages) has announced ABRIS, a new AABR
softure module for their MedPC or the Eclipse
black box line of products. According to the company
the ABRIS software module offers: (1) Extremely short test time
(typically approx. 20 secs and (2) Lowest ABR screening cost per
child (no consumables if BERAphone is used as transducer). For
further details you can consult a technical leaflet
(1.5 M) or visit the appropriate web
pages at the Interacoustics site.
|
|
27/08 |
- The future highlights
section was updated with material which will be presented until
February 2005.
|
|
12/08 |
|
|
10/08 |
- We have placed on-line a beta-version
of the Book-project pages. We will
be waiting for some additional input from you
before placing the definite style on line.
|
|
02/08 |
- The month of August the staff of the OAE Portal will
be on vacation and updates and news will be posted until
August 12th and then from August 24th.
|
|
22/07 |
- From our contacts in Denver University
and from our web editorial staff we have gathered
the following updates related to NHS
activities around the globe :
1. Poland is reporting that they are the first
country in the world to be universally screening all newborns.
See the relative
editorial for additional details.
2. Dr. Randi Wetke from Aarhus Hospital,
has mentioned to one of our staff members during the last AAA
meeting that they have a pilot program that will be funded by
the government to start screening. It probably has already begun.
3. Canada is screening in the province of Ontario
and Nova Scotia. The state of Vancouver
has finally convinced the government to begin some screening,
and Manitoba, has screening started but only
in a few hospitals.
4. In Australia they have screening programs starting up in almost
ever province or state. New South Wales' program
is doing very well and the latest news refer to a program starting
in Victoria. An interesting remark is this :
The government in Western Australia had decided to terminate
their screening program because they were identifying only 1 in
every 6000 births. But then newer information
indicated that they decided not to terminate the program.
5. The UK's program is doing
very well. A very positive issue (screening-wise) thing about
their program is that they won't start up the hospitals until
all the follow-through is in place.
|
|
19/07 |
- The latest technical preparation regarding the Open
FORUM space indicate an opening time around the first
week of October 2004.
- Due to the elevated interest to issues related to EHDI
programs and NHS protocols we will occasionally
provide information we collect from various colleagues and Portal
users. The objective of this type of posting is to stimulate
the relative Program administrators to send us more information
about their activities and primarily on NHS problem-solving.
|
|
12/07 |
|
|
01/07 |
- The future highlights
section was updated with material which will be presented until
November 2004
- We are very happy to welcome to the Portal Editorial Board Dr.
Stavros Korres. Stavros is a graduate of the
University of Athens Medical School (1967). He
obtained his ENT Specialty in 1972 from the University
of Liege, Belgium. He did post-graduate studies in London from
1972 to 1979 in Neurotology and Audiological
Medicine at the National Hospital for Neurology and Neurosurgery,
Queen Square. From 1979 until now, he is working
at the University of Athens (Hippokration and Aiginition Hospital)
as an Associate Professor of Otorhinolaryngology.He is interested
in applications of otoacoustic emissions / neonatal screening
and in vestibular research.
He
has contributed to the Portal a number of reports related to the
status of NHS in the Greek model (Newborn
hearing screening program in Greece: outcomes after six years
of successful implementation)
|
|
25/06 |
- The neonatal
screening section of the on-line powerpoint
lectures has been updated with the synopsis of 3 lectures
by Dr. Stavros Hatzopoulos titled "An
Overview of the technologies used in NHS / UNHS (Otoacoustic Emissions
and Automated ABR)". The material has been presented
in various European and American meetings in 2003-2004 and will
be the basis for the forth-coming round table
session at the 2004 ISA meeting
in Phoenix (see meetings & Workshops or the announcement
below), this coming September.
- The XXVIIth
International congress of Audiology (ISA) will take place at Phoenix,
Arizona from September 26 -30th. The keynote Speaker will be David
Kemp, who will speak on the 25 Year History of
the study of OAEs. He will lead off the Congress on Monday,
September 27th. Several round tables related to OAEs have been
organized and there is a whole day dedicated to Pediatrics. Deadline
for abstract submissions is June 30th, 2004.
|
|
22/06 |
- The transfer of the OAE material to the
new Server has been finalized and we will be start updating the
pages of the POrtal on the 25th of June, according
the pre-announced schedule. If for any reason you find some links
which are not functional please let us know
ASAP.
|
|
12/06 |
- We do apologize
in advance but in the period between June 13th to June
20th due to the immigration of the material to faster servers, you might not be ABLE to access
some sections of the Portal. Of course our technical consultants
will try to do the upgrade without any disturbances in the access
of the available information.
|
|
08/06 |
- We are very happy to welcome to the Portal
Editorial Board Dr. Bradley MacPherson from the
University of Hong-Kong. Brad gained a B. A.
in Psychology from the University of Sydney and postgraduate audiology
qualifications from the University of Manchester and University
of Queensland. Brad has worked as an audiologist in Australia,
England, West Africa, South Africa, Asia and in the Middle East.
From 1989 to 1996 he was a Lecturer/Senior Lecturer in audiology
at the University of Queensland, Brisbane, Australia. Since that
time he has been an Associate Professor in the Division of Speech
and Hearing Sciences, University of Hong Kong. His teaching and
research interests include pediatric hearing screening techniques,
especially OAE procedures, and hearing loss in developing countries.
He has co-authored over twenty scientific research publications
in the OAE area.
- Dr. Panagiota Lalaki will
join the group of assistant web editors, with target area the
Mediterranean countries, including those of North Africa.
|
|
04/06 |
- A number of activities have delayed the update
of various sections of the Portal. The main reason is the forthcoming
chance of server (incrementing the available
bandwidth and speed) and the layout of the new OAE FORUM
space (see the section Editor's
Perspective for additional details).
|
|
03/06 |
- After numerous requests regarding the proper
printing (which until now was broswer-type depending)
of the on-line Powerpoint lectures, white papers and editorials
we have decided to gradually introduce the pdf Acrobat
format which is very common to both PC and Mac platforms.
From
June 2004 all powerpoint lectures will be downloaded
as pdf files and for the editorials and white
papers pdf files will be also available.
|
|
22/05 |
- Next week (26 - 29 of May) the
NHS-2004 will take place at Cernobbio close to
the Como lake in Italy. Web assistant editor Dr. Antoni
Grzanka will be present and you can contact him for matters
related to the Portal.
|
|
18/05 |
|
|
15/05 |
|
|
13/05 |
- As it was announced in April (From the
Editor) in the second week of May the Guest editorial
will present information from another screening program. Dr.
Marzanna Radziszewska presents an information-update
on the screening program in Poland.
|
|
02/05 |
- As it was announced earlier this year we
are considering the implementation of a FORUM
inside the Portal, addressing three main areas of arguments :
(1) Biophysics and OAE Modeling ; (2) Neonatal Screening are related
issues (hardware + software issues); (3) Clinical OAE applications.
We are hoping that this way the interaction between members of
the OAE community will be faster and more efficient.
One possible
limiting / inhibiting factor towards the realization of the FORUM
(which ultimately expresses the free opinions of the OAE community)
is related to how to control the quality of arguments
and the behavior of the participants, specially
in conflicting arguments. We would like to hear from you on this
issue, so please contact us here.
|
|
23/04 |
- The web assistant editor Dr. Antony
Grzanka and Dr. Wiesiek Konopka
have contributed a white paper describing the possible novel use
of of Time-Frequency
analysis in biometric applications . The paper can be found
in the signal processing
section of white papers.
The original article in Polish appeared in Otolaryngol
Pol 2002 ; 56: 701-06.
|
20/04 |
- As the NHS-2004 dates are coming
closer (May 27-29) more information is available
from the NHS-2004
site. The latest news from the organizers indicate that more
than 280 submissions have been received . The program will include
Keynote Addresses, Special Sessions, more than 100 oral communications
and more than 170 poster presentations on issues in screening
and pediatric audiology and otolaryngology, parents/family support,
intervention, cochlear implants, evoked potentials, middle ears
measures, advancement in assessments, basic investigations, amplification,
cochlear implants, genetics, speech-language development and health
services. NOTE: If you are planning to join the
meeting , reserve a room fast because the reported
room-availability is low.
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|
16/04 |
|
09/04 |
|
|
07/04 |
- We have recommended numerous times to our
visitors, who are interested in cochlear biophysics
to visit the site auditorymodels.org,
in order to get the latest information on the status of cochlear
models and OAEs. One of the most recent postings is quite interesting,
as it refers to new studies suggesting that the backward
traveling wave (which in theory generates what we record
as TEOAEs and DPOAEs) actually does not exist.
"On
Tues, 30 Mar 2004, Andrew
Bell wrote: List members will no doubt be interested to note
a recent paper by Tianying Ren [Nature Neuroscience, 21
March 2004] which supplies a convincing demonstration
that the reverse traveling wave in the cochlea does not exist.
Instead, Ren could find only a fast backward compressional (pressure)
wave. The reverse traveling wave is a key entity required by conventional
cochlear mechanics to explain acoustic emissions of all kinds,
including, in the case under observation, distortion product emissions
(DPOAEs). The 2f1-f2 distortion product, for example, originates
at a location on the partition through non-linear interaction
of two primary tones (e.g., 17000 Hz and 15455 kHz in one gerbil
experiment reported) giving a strong vibration at 13910 Hz; this
tone is presumed to travel backwards, via a traveling wave of
displacement, to the stapes and the ear canal, where it is detected.
To Ren's surprise, he found with his scanning laser interferometer
that he could detect no displacement of the basilar membrane at
13910 Hz until after_ the stapes had started vibrating at this
frequency. That is, the tapes vibrated some 50 us _before_ the
basilar membrane did. There must have been a fast (nearly instantaneous)
compressional wave at 13910 Hz which originated at some distance
along the partition and excited movement of the stapes; only later
did the basilar membrane join in.
This
paper will cause us to reexamine the basics of
how the cochlea works. A couple of years back discussion on this
list centred around the question of whether the (forward-) traveling
wave is itself an epiphenomenon, arising only
as a consequence of outer hair cells reacting
to a fast pressure wave entering the cochlea. This latest work
gives strong support to this notion. If outer hair cells can produce
a fast pressure wave, it seems natural to suppose that, by reciprocity,
the fast pressure wave is the key stimulus in the cochlea."
|
03/04 |
- The main pages of the neonatal
screening section were re-organized and updated. There is
a new section termed "Alternative
Technologies" where we will presenting information related
to Auditory Steady State Responses (ASSR) and
Automated ABR.
|
|
30/03 |
- The web assistant editor Dr. Katia
De Almeida will be attending the AAA meeting at Salt
Lake (starting tomorrow) . If you want to contact her for
any issues related to the Portal please send her an email
message from any INTERNET station in the conference .
|
24/03 |
- The second of the two scheduled updates on DPOAEs
in the OAE definitions section,
is now available on-line.
- Another review of the Portal is now on-line.
The review was presented in ENTNews (September
/ October 2003 issue) by the INTERNET columnist Dr. Tunde
Odutoye.
|
|
18/03 |
- GN-Otometrics
has announced the release of a new portable device for middle
ear measurements called Otoflex
100, which can complement the AccuScreen
line of portable OAE devices. Interested users can visit the Sponsored
Pages of GN-Otometrics for further information.
|
12/03 |
|
|
02/03 |
- The first of the two updates (scheduled for this month) on DPOAEs in the OAE definitions section, is now available on-line.
|
26/02 |
- The section of Future
Highlights was updated with material which should be available on-line
until May 2004.
|
|
23/02 |
- The FACTS-sheet for the year 2003
are now on line. The statistics indicate that visitors from 77
countries have visited the Portal in 2003 with the majority (56.5%)
coming from the US and Canada. The most downloaded pages (except
the material on OAE definitions and Hardware) were from the white
papers section and not from the free
Powerpoint lectures (data from 2002).
|
18/02 |
- The section of OAE-Links
was verified and updated . Unfortunately the number of sites which
offer some sort of qualitative information on OAEs is decreasing
(ie some older links were found inactive).
- Otodynamics
has updated the software for the ILO file visualization with a
new package called EZscreen2. Interested users
can download a free brochure (158k) from here
, or contact Otodynamics
for questions on how to get the new software.
|
|
17/02 |
- The pages on OAE-Hardware
were updated with new models of automated OAE
hearing screening and data acquisition.
|
09/02 |
- The section of Biophysics
and OAEs has been updated with two sub-sections on (i) Noise
and OAEs and (ii) Cisplatin
ototoxicity and OAEs. Due to the changes in these fields the
sections report the developments in OAE research only for the
last few years (1998 and beyond). Additional
material on otoprotection will be available in 2004.
|
|
02/02 |
- The section of future
Highlights was updated with the forth-coming white papers in
March, April and May 2004.
|
26/01 |
|
|
21/01 |
- The latest data in the literature suggest that
the generation mechanism of the transiently evoked otoacoustic emissions
is related to a reflection of the incoming traveling wave energy
at randomly positioned locations of the basilar membrane. It is
believed that the TEOAEs are formed by the dynamics of the cochlear
amplifier in combination to the geometry of the cochlear partition.
It is very refreshing
to see another approach to the matter by the well known group of
physicist Dr. Renato Nobili. In a forthcoming paper
at JARO the authors suggest that the emissions
are formed by an irregular middle ear function which introduces
long lasting residual oscillations on the Basilar membrane. The
abstract of their paper follows:
ABSTRACT: Otoacoustic Emissions
from Residual Oscillations of the Cochlear Basilar Membrane in
a Human Ear Model. Authors: Renato Nobili, Aleš Vetešník,
LorenzoTuricchia and Fabio Mammano JARO, 2003.
Sounds originating from within the inner ear, known as otoacoustic
emissions (OAEs), are widely exploited in clinical practice but
the mechanisms underlying their generation are not entirely clear.
Here we present simulation results and theoretical considerations
based on a hydrodynamic model of the human inner ear. Simulations
show that, if the cochlear amplifier (CA) gain is a smooth function
of position within the active cochlea, filtering performed by a
middle-ear with an irregular, i.e. non-smooth, forward transfer
function suffices to produce irregular and long-lasting residual
oscillations of cochlear basilar membrane (BM) at selected frequencies.
Feeding back to the middle-ear through hydrodynamic coupling afforded
by the cochlear fluid, these oscillations are detected as transient
evoked OAEs in the ear canal. If also the CA gain profile is affected
by irregularities, residual BM oscillations are even more irregular
and tend to evolve towards self-sustaining oscillations at the loci
of gain irregularities. Correspondingly, the spectrum of transient
evoked OAEs exhibits sharp peaks. If both the CA gain and the middle-ear
forward transfer function are smooth, residual BM oscillations have
regular waveforms and extinguish rapidly. In this case no emissions
are produced. Finally, and paradoxically albeit consistent with
observations, simulating localized damage to the CA results in self-sustaining
BM oscillations at the characteristic frequencies (CFs) of the sites
adjacent to the damage region, accompanied by generation of spontaneous
OAEs. Under these conditions, stimulus-frequency OAEs, with typical
modulation patterns, are also observed for inputs near hearing threshold.
This approach can be exploited to provide novel diagnostic tools
and a better understanding of key phenomena relevant for hearing
science.
- Dr. Nobili very generously has
provided to the OAE community MATLAB based simulations of his
TEOAE model. Interested readers (who have access to MATLAB)
should check-out the simulation
pages in the Portal or access his TEOAE simulation model here.
|
18/01 |
- We would like to remind our visitors that the
deadline for abstract submission for
the NHS-2004 meeting, in Como Italy is
on January 20th. You can submit your
abstracts by visiting the web site of NHS-2004
or by clicking this link.
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16/01 |
- The section on OAE
simulations was updated with another DPOAE simulator . The
original code was written by David Brass (Otodynamics)
and the program was distributed for free as a companion of the
book "Otoacoustic
Emissions: Basic Science and Clinical Applications" , edited
by Dr. Charles Berlin and published by Singular
Press. You can download the executable file (140
K) by clicking here
. NOTE: MAC users have to use a simulator like
Virtual PC to be able to see the simulations .
|
09/01 |
- We are very proud to present some of the work
of Dr. Michael Berg dedicated to simulation
programs for DPOAE generation. Dr. Berg studied
theoretical physics in Erlangen and in 1975 changed to
medical physics at Erlangen ENT-University-Hospital with
Proof. Dr.med. Malte Erik Wigand. He was head of the Erlangen
Audiology Dept. from 1975 to 1999 and worked in various
fields as in neurophysiology, subjective and objective
audiology, vestibular diagnostics, rhino-manometry, super
acoustics of the maxillae salivary chemicals, and didactics
of medical physics. From 2000 he retired from his role
as a director and he happily returned to model
making and code writing ....
His generous contribution
to the Portal includes a software package for DPOAE
simulation, he elegantly calls the Tartini tone,
and a theoretical text file
presenting basic information and math about cochlear mechanics
and generation mechanisms of DPOAEs. These items are
available in the newly-designed software
section of the Portal dedicated to OAE simulators.
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07/01/2004 |
- The section on Neonatal Screening Programs
from around the World,
was updated with an introductory presentation of the program in
Belgrade, Serbia
and Montenegro.
- If you are interested in starting
a neonatal hearing screening program in your area, things are
a lot easier than you think. As the impetus of
the hearing screening practices is still booming, there are much
more available resources (financial and not)
NOW than the years past. We are presently compiling
a case-study of a new program in a developing country (more details
from March 2004) and we will post the information
in the Portal for other interested users.
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