December
23th 2002 |
- The last update of 2002 refers to a re-organization of the material related to noise in the biophysics section . In 2003 this section will be updated with a chapter dedicated to cisplatin and possibly aminoglycoside ototoxicity.
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December
17th 2002 |
- We have started working on the re-organization of certain sections of the Portal, such as the theoretical aspects of OAEs and Clinical applications of OAEs, which contain the most requested web pages. In early 2003 we will change also the visual interface of the portal.
- From 2003 we will eliminate the section on OAE meetings ( from the left panel) and we will substitute it with a section on the main page. There are very few meetings dedicated to OAEs, and most Audiology, Hearing Science, and ENT congresses offer OAE sections and round tables. The new section on OAE meetings will have the purpose of advertising LOCAL events even in languages other than English. Organizers who wish to advertize their events with us, can send an email message to this address:
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December
7th 2002 |
- The section on the clinical section of the OAEs, has been re-written and expanded. We have considered also advantageous to provide you with more information on the relationship between OAEs and tinnitus. The reports we have from the literature do not suggest a significant relationship, but anecdotal work has shown that the OAE patterns around the tinnitus region is rather abnormal. More information on the tinnitus-OAEs issue will be available in 2003.
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December
2th 2002 |
- We have compiled a list of Portal collaborators, which appears under the section Who are we. The list is organized alphabetically in terms of the countries of origin of our collaborators. In this list we have excluded the POrtal web editors and the members of the editorial board. So far we have received contributions from 50 colleagues belonging to 12 different countries. As it might be expected the majority of contributions (editorials, white papers and on-line lectures) comes from the US.
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November
26th 2002 | |
November
19th 2002 |
- The first BETA version of the Italian OAE Portal is on-line. The tweaking processes will last until the end of November.
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November
18th 2002 |
- The standard rhythm of updating the material in the English Portal will be slowed down, for another 7 days time necessary to put the Italian Portal on Line.
- The Impact Factor page, in the OAE articles /MEDLINE section, was updated with the listings for 2001.
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November
12th 2002 |
- The section on OAE Hardware has been updated and numerous new pages have been added. The information related to changes in the OAE devices (new models, software improvements,etc) is now presented in newly designed sections called "the latest updates", for each OAE manufacturer. For companies which do not correspond regularly with us the updates will be conducted on a six-month basis.
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November
7th 2002 |
- The section of OAE Hardware has been updated with new entries in the OAE market such as Echolab from Labat Biomedical Devices, Echoscreen-TDA from Fischer-Zoth and Smart-OAE from Intelligent Hearing Systems.
- Otodynamics has changed web address and web-format. The new site is easier to navigate and contains a lot of information on the company's products and accessories.
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November
4th 2002 |
- The section of neonatal screening programs around the World has been updated with a contribution from Dr. Danilo Cosso. Danilo is a neonatologist and one of the main components responsible for the success of the screening program in the area of Genova ( Italy). Although we are accustomed in reading numbers and percentages about the sensitivity and specificity of universal screening programs, Dr. Cosso underlines the necessity to not Forget the human factor in a neonatal screening program.
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October
30th 2002 |
- We are very pleased to welcome on the editorial board of the Portal Ms Jenny Chan (MS). Jenny is right now with the Audiological Services of the Education Department of Hong-Kong. Her interests include application of different OAE measurements in the Chinese population; Facilitating professional interflow between China and other countries. A guest-editorial on the activities of the Eastern OAE community will appear in early 2003.
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October
26th 2002 |
- We are very pleased to welcome on the editorial board of the Portal Dr. Elmar Oestreicher. Elmar he is currently with the ENT department of the Technical University of Munich and his interests include neurotransmission of the inner hair cell synapse, neurotransmission of the auditory pathway, protection and therapy of inner ear diseases, and tinnitus. A guest-editorial on Tinnitus and OAEs will appear early next year.
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October
22th 2002 |
- Due to large number of changes in the section of OAE -hardware the various updates will appear from the month of November in combination with the launch of the Italian sub-Portal. Two new sub-sections will appear in the hardware lists. A section called "Feedback" where we will place solutions to various software and hardware problems associated with a specific product; and a section called "Updates" where we will post news about the products of a given manufacturer.
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October
19th 2002 |
- Despite the fact that (almost exclusively) third generation portable OAE equipment are being employed in new hearing screening and EHDI programs, we have periodically received a number of requests for scripts which can automate the acquisition of data with second generation equipment (ILO-xx series, Capella series , GSI-60, Biologic AUDx etc). For this reason we are opening a new section in the software pages called "Scripts and macros". The first script refers to a macro applicable to the DPOAE series of ILO equipment (ILO-92, ILO-292, ILO-96) and it has been used in a number of European labs and hospitals for neonatal screening (WBs). The macro can be easily modified to match the needs of other applications (hearing evaluation in the NICU, carriers of genetic syndromes, ototoxicity and noise monitoring etc). Users of the Capella, GSI and Biologic clinical systems who have developed similar scripts and they are willing to share them with the rest of the OAE community, can contact us by clicking here.
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October
14th 2002 | |
October
10th 2002 |
- The material on Basics of OAEs in the TEOAE section was updated. Two more aspects of TEOAEs will be revised in the next few months. The new methodologies of TEOAE signal analysis (statistical TEOAE estimation, time-frequency analysis of the responses, non-parametric spectral TEOAE estimation etc) and the biophysical basis of the TEOAE generation. Readers who are interested in the latter should read the following article Shera CA, Guinan JJ Jr (1999): Evoked otoacoustic emissions arise by two fundamentally different mechanisms: A taxonomy for mammalian OAEs. J Acoust Soc Am 105:782-798.
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October
4th 2002 |
- The material on biophysics and OAEs in the on-line lectures section was updated with a contribution of our group in Ferrara . The material was presented at the 39th meeting of the Inner Ear Biology at Liege Belgium. The presentation is titled "Are distortion product otoacoustic emission (DPOAE) responses amplified, after carboplatin treatment ?" and presents data on the lack of any suppression / enhancement effects on the DPOAEs, after IHC functional alterations (verified by ABR measurements) caused by a 30 min slow intraperitoneal administration of carboplatin (Paraplatin).
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September
30th 2002 |
- The section on Basics of OAEs -DPOAEs was updated. The Introduction section contains now information related to cochlear mechanics.
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September
25th 2002 |
- In the last 6 months a number of visitors has requested access to papers from Italian and non-Italian authors, which they cannot obtain in their home countries. Although we are hosted in a mainframe with a large memory capacity we cannot afford to have on line the requested OAE papers on a global scale (not to consider issues of international copyright). In the view that the Italian Sub-POrtal will air in a few weeks we have decided to offer a limited number of papers on line from Italian authors. These papers are offered in a pdf format (Adobe Acrobat) and they are normally small (300 - 700 k) and easy to download. If you are an Italian author and have a paper you would like to have on line please contact us.
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September
21th 2002 |
- The white-paper section of clinical applications was updated with a contribution of Dr. Carlie Driscoll titled "A Normative Study of Distortion Product Otoacoustic Emissions in Six-year-old School Children" . This presentation is a synopsis of a paper Dr. Driscoll and her collaborators presented in the International Journal of Audiology (IJA, 2002; 41: 162-169). The paper presents data which show that there is a significant ear asymmetry, gender and history of ear infection effects upon DPOAE results, and suggests that the use of separate norms for six-year-old children in school settings should be considered.
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September
16th 2002 | |
September
12th 2002 |
- We are very pleased to welcome to the Editorial Board of the OAE Portal Dr. Eric LePage. Eric has trained as a cochlear physiologist in the auditory laboratory at the University of Western Australia, where he gained his doctoral degree providing the first confirmation of the existence of nonlinear mechanical behaviour in the cochlea. These findings were presented at the same meeting (London, 1980) when otoacoustic emissions became widely accepted. After post-doctoral projects at Washington University in St.Louis, Boston University and the University of Tuebingen he returned to join the National Acoustic Laboratories in Sydney, which is the research arm of the large Australian Hearing clinical network. There he continues full time research into otoacoustic emissions, both from their theoretic origin and clinical application, with team members audiologist Narelle Murray Ph.D., and physicists John Seymour and Dan Zhou.
With his co-workers he has accumulated one of the largest databases of click-evoked otoacoustic emissions which includes a ten-year longitudinal study of orchestral musicians. This database shows that it is possible to distinguish environmental factors upon TEOAE patterns long before symptoms of hearing loss develop. The NAL-OAE software package was developed in recent years to make available a TEOAE method to provide early warning of increased risk hearing loss in adults as well as the more generally accepted application of OAEs to provide early detection of hearing loss in infants. In recent days, an agreement has been struck with GN Otometrics to market this Windows program.
Eric's primary research foci continue to be the physiological response to factors which accelerate aging of the cochlea, the role of the efferent system, and the extent to which otoacoustic emissions and mathematical models can provide us with information about cochlear mapping.
- In the remaining months of 2002 we have programmed to enhance the material related to the biophysical application of OAE technologies, mainly focusing on issues of cochlear insults caused by ototoxic drugs or noise.
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September
2nd 2002 |
- We are very pleased to announce that work has begun on the Italian section of the Portal. According to our estimations the related pages will be accessible sometime around the end of next November. Although the pages in Italian were created as a homage to our hosting country, there are no future plans to expand the national number of sub-portals due to problems related to availability of resources. As it was announced last month, when the Italian sub-Portal will be activated the main material of the Portal will be accessed only from the www.otoemissions.org address.
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August
19th 2002 |
- After a month of summer inactivity gradually the members of the editorial board ,one by one, are coming back on-line !!
- The on-line lectures section on neonatal screening was updating with a contribution of Dr. Brandley McPherson. He is sharing with us the data he presented during the NHS-2002 meeting in Como, on the use of tone-burst OAEs (TBOAEs) in neonatal screening. The advantage of using TBOAEs is two-fold. (i) the TBOAEs present better S/N ratios than the traditional TEOAEs; and (ii) Sometimes TBOAE peaks have been observed in ear with missing TEOAEs. Although the data of Dr. McPherson refer to preliminary data from young adults(4 tested frequencies at 1, 1.5, 2 and 3 kHz) , they suggest that TBOAEs might have an excellent potential in hearing screening.
| July
15th 2002 | |
July
10th 2002 |
- The section on recent MEDLINE articles (vol 4, 2002) was upgraded.
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July
4th 2002 |
- I am very pleased to announce that we have placed on line two lectures by Dr. Douglas Keefe, related to the topics of acoustic reflectance and admittance. In the first lecture Dr. Keefe presents a synopsis of the main concepts associated with acoustic admittance and its importance in neonatal screening. In the second lecture he shows how to use Middle-Ear Measurements to Interpret Cochlear, Sensorineural, and Behavioral Responses in a Study of Neonatal Hearing Impairment. Dr. Keefe has also generously added some valuable comments on the slides of the second lecture.
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July
1rst 2002 |
- The second report on the Como NHS-II meeting, by assistant web editor Thierry Morlet Ph.D. is now on line.
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June
20th 2002 |
- We are very pleased to introduce a piece of interesting work in the area of OAE clinical applications with the white paper of Dr. Orhan Ozturan titled "Effects of the electromagnetic field of mobile phones on hearing". The original article was published in ACTA-LARYNGOLOGICA (April 2002). Dr. Ozturan is a Professor of Otorhinolaryngology at the Inonu University, School of Medicine, in Malatya Turkey and his contribution is a valuable addition to the OAE field considering the rarity of reports on TEOAEs and DPOAEs related to ears exposed to the EMF radiation of the cellular (mobile) phones.
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June
18th 2002 |
- Dr. Pierre Bonfils did a review of the OAE Portal for Acta-Laryngologica. The review will be publish in the September 2002 issue of ACTA. A preview of that report has already placed on line.
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June
15th 2002 |
- We have requested from the majority of OAE manufacturers an update on the status of their OAE hardware. As the information will come in, we will update the appropriate pages in the OAE-hardware section of the Portal.
- There are several changes in the SmartOAE line of products from Intelligent Hearing Systems-IHS. The current SmartOAE software has been renamed to SmartDPOAE and a second module, named SmartTrOAE, is currently under FDA approval. We will update the IHS pages when the FDA will approve the module.
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June
12th 2002 |
- The first report on NHS-2002 from our Web editorial board is now on line.
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June
8th 2002 |
- There are several trends in the OAE hardware, which we observed during the NHS-II meeting in Como. The OAE manufacturers are targeting mainly neonatal screening applications, offering small and simple to operate devices, capable of multiple types of OAE tests. We were told that more devices will be available from the Fall 2002.
- Maico has presented a small portable unit which is capable of recording TEOAEs and DPOAEs. The company has released also a presentation-CD which can be requested by sending an email message to Wolfgang Köpke, Managing Director of the European office in Germany.
- Fischer-Zoth has announced a small portable unit which can combine TEOAEs, DPOAEs and ABR. The first units will be available from September 2002.
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June
5th 2002 |
- Dr. LePage , from the National Acoustic Laboratories in Australia, has informed us that the TEOAE analysis software NAL has been further developed. A synopsis of the new and old features has been presented as a poster at the last ISA meeting (2002) in Melbourne Australia. The poster can be downloaded as a pdf file from here.The software comes in two versions, one standalone for the ILO .dta files, and a NOAH version which reads both ILO and Capella files. Progressively, new data processing features are being added. File comparison is a central feature.
While the software displays RI criteria, it also displays NAL-RISK criteria which refers to the Australian Database of 15000 records and computes a probability of hearing loss. This has great potential as an early warning indicator. If you have further questions you can consult the NAL page in the Portal, or write directly to Dr. LePage
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June
4th 2002 |
- The important event of these days was the second International meeting on Neonatal screening (NHS-II) at Como, Italy. The meeting drew more than 540 people from many countries and it was ran in a impeccable manner. Two reports on the meeting will be available as sub-editorials in the months of June and July.
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June
2nd 2002 |
- It seems that as INTERNET technologies mature, the web becomes not only a searching tool, but a publishing means of scientific material. We have receive the following information and we have considered appropriate to share it with the rest of the OAE community.
We are writing to invite you to publish your research in one of the open access online journals published by BioMed Central
All research papers published in BioMed Central's journals are peer-reviewed, indexed in PubMed, the most widely used bibliographic database for the biomedical sciences, and immediately and permanently archived in PubMed Central , the NIH open access repository for peer reviewed research. We are also working closely with the ISI to ensure that all our journals are citation-traced for impact factors, and many of our journals are already covered. Unlike other science publishers, we do not ask you to transfer copyright to us and our rapid electronic peer review process enables average processing times, from submission to publication, of eight weeks. We are committed to giving articles of extraordinary significance or interest the widest possible audience by issuing press releases and commentaries on them.
BioMed Central publishes over sixty journals covering the breadth of biological and medical science. If you are interested in submitting a research paper , simply follow the instructions on our website. If you feel that that your research area is not covered by any of our existing journals, you may be interested in starting an open access online journal under your own editorial control. BioMed Central provides free hosting and use of our complete publishing systems and technical expertise.
BioMed Central does not charge any subscription fees for access to any research article. We cover the cost of our services by levying a processing charge of $500 for each published article. This charge allows us to ensure that articles are published rapidly, that their integrity is maintained, that they are securely archived, and are searchable and retrievable. It allows for rapid, worldwide free access to the research, and we believe it compares favorably with the current costs of page charges, color figures and in some cases processing charges, levied by journals that limit access through high subscription charges.
We are aware that processing charges may create difficulties for some researchers. We therefore have several ways of minimizing the burden on individuals. First, the charges are waived for authors from developing countries and others who are unable to pay. Second, we are inviting institutions to join BioMed Central . Among other benefits, researchers at member institutions receive automatic waivers of processing charges. Depending on the size of the institution, annual membership for 2002 will cost between $1500 and $7500. We would be grateful if you could raise this with the head of your institution, or let us have their contact details so that we can do so on your behalf.
If you have any questions about publishing in these journals please contact by email:Fiona Godlee,Editorial Director (Medicine),BioMed Central
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May
24th 2002 |
- During the NHS-II meeting which starts Thursday (30-5-2002), next week at Como Italy, three members of the web editorial board (Dr. Hatzopoulos, Dr. Morlet and Dr. de Almeida) will be available for questions and answers regarding the OAE Portal activities
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May
22th 2002 |
- The web-related technologies are slowly entering into the OAE field. OZ systems has announced a new generation of newborn screening information management system, called ESP (e-screener plus). The advantage of the new technology is that it can be installed in a main server and then used as a web application by a number of PCs. An electronic brochure of the new program can be downloaded from here.
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May
16th 2002 | |
May
10th 2002 | |
May
6th 2002 |
- The annual meeting of the American Society of Audiology is considered an excellent opportunity to show the latest advances in new hardware. In this year's meeting in Philadelphia, we did not see significant changes in the OAE manufacturers equipment forum. The latest news in this area, is the collaboration between Everest Biomedical and Grason Stadler, for the exclusive distribution of a portable unit called AudioScreener with ABR and OAE recording capabilities. For more information on the this product you may consult this web address. In the newly designed site there is also a downloadable (highly reccommended) FLASH utility which simulates the functioning of the AudioScreener
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April
27th 2002 |
- We have re-designed the biophysics section, with 4 extra pages one of which is dedicated to NIHL and oto-protection. The topic of oto-protection is one of the hottest issues in current inner ear research and for this purpose the page dedicated on NIHL contains a list of relevant papers on a number of oto-protector molecules.
After the second editorial on cisplatin and OAEs, we will add another page in this section dedicated on the clinically used antioneoplastic molecules (cisplatin , carboplatin) and the induced ototoxicity from the OAE perspective.
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April
21th 2002 |
- We are very pleased to report that in the clinical section of the White papers we have added a contribution titled "Spontaneous and Transient Evoked Otoacoustic Emissions: A Racial Comparison" by Jenny Chan and Bradley McPherson, from Hong-Kong University. Their work first appeared in JAM in 2001 (vol 10 pp20-32)and regards a comparison of TEOAE and SOAE signal characteristics between Chinese and Caucasian groups.
The results of their study suggest that there are racial differences in the OAEs from the tested population samples. Main factors were considered the differences in middle-ear mechanics, dimensions of the external acoustical meatus and the melanocyte distribution of the inner ear. We hope that these data might stimulate further investigations into this interesting topic.
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April
15th 2002 | |
April
10th 2002 | |
April
6 th 2002 | |
April
3 rd 2002 |
- The section on Biophysical research and modelling was updated.
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March
30th 2002 |
- The section on recent papers in the OAE Articles -MEDLINE section was updated.
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March
28th 2002 | |
March
25th 2002 |
- The last 5 months we have received messages from a number of users informing us that certain pages in the Portal are NOT properly visible with the latest browser from Netscape (6.xx). During the month of March the core code of the majority of pages has been updated resolving the majority of visual problems created by Netscape 6.xx browsers. If you STILL find a page which does not show properly please let us know.
If you are wondering why do we bother to "correct" our web pages so that they are equally visible by the major browsers, we would like to inform that the Microsoft Explorer is being used by approximately 80% of the INTERNET users.
The next task of our software technicians will be to adopt the code to the new versions of the Opera browser !!!!
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March
22th 2002 |
- The section of white-papers on Signal Processing and OAES was updated with a contribution titled Recurrence Quantification analysis and Transient Otoacoustic Emissions ,by Giovanna Zimatore Ph.D. Dr. Zimatore works for the Department of Biochemical Sciences of Roma University "La Sapienza" and she is interested in new methodologies of biological signal modelling applicable to the cochlea. Her paper describes the foundations behind an important alternative method of TEOAE analysis, called recurrence quantification analysis (RQA). This approach provides us with the possibility to analyze and de-compose the TEOAE responses NOT using the traditional fast Fourier transform (FFT). The paper is for advanced users with a certain experience in signal processing and statistics.
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March
14th 2002 |
- The section of on-line lectures related to OAEs and Biophysics was updated with a contribution from Dr. Natalie L.M. Cappaert titled "A comparison of three evaluation methods for ototoxicity after ethyl benzene exposure". Dr. Cappaert comes also from the Hearing Research Laboratories, University Medical Center Utrecht University, and her contribution is part of her Ph.D. thesis. What makes her presentation even more interesting is the observation that "Compound Action Potential (CAP) threshold shifts were statistically significant and in line with OHC loss, but DPOAE measurements merely showed a trend for loss. Thus, DPOAEs seem to be less sensitive than CAP and OHC counts". This statement should make us reflect on our ideas that DPOAE testing is one of the most (or the most) sensitive index of cochlear function.
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March
9th 2002 |
- In response to a number of requests regarding the "national" connotation in the http address of the OAE Portal (www.oae.it) we are pleased to announced that we have registered another name. You can access the Portal material by using http://www.otoemissions.org .
This decision was taken because in the future we are planning to separate the Portal material into two categories: (1) Italian OAE activities accessed by www.oae.it ; (2) International OAE activities accessed by the new name www.otoemissions.org.
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March
4th 2002 |
- Editor's Note: The policy of the Portal regarding the on-line lectures has changed from 1/3/2002. Despite the fact that many of you are connected to the INTERNET with fast 56K modems, we have been signalled that many times it was very difficult to save all the pages of an on-line lecture. Now you can download the lecture you are interested in directly from the appropriate pages (Biophysics, clinical, etc). The files you can download are self-unzipping (each file ends with an "exe"). Each lecture is saved in an HTML format and you can view it by any currently available browser (Netscape or Explorer). A "preview" feature for each lecture will be available after 11/3/2002.
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March
1rst 2002 | |
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| February 26th 2002 |
- The clinical section of the on-line lectures has been updated with a contribution on the Clinical Studies of medial efferent olivocochlear function from Dr. Charles Berlin, Director of the Kresge Lab in New Orleans. The on-line lecture is an abridged version from a lecture Dr. Berlin presented during the ARO meeting of 2002, for a forum on the The Medial Olivocochlear System And Otoacoustic Emissions: Physics, Physiology, Psychophysics and Clinical Applications, organized by Duck O. Kim and M. Charles Liberman.
In this presentation, Dr. Berlin, summarizes several years of research on the medial efferent olivocochlearsystem (MOCS) in humans. Studies of otoacoustic emission suppression haveshown that the MOCS effect is reliable and valid and exits separately fromthe middle ear muscle reflex. Dr. Berlin explains what parameters should beused to elicit the medial olivocochlear reflex and what results should beexpected according to age and hearing condition.
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| February 25th 2002 |
- We would like to apologize for an interruption of our services from Sunday afternoon (February 24th) until today (13:00) . Simply, the Computer Science center of Ferrara University was disconnected from Internet due to a malfunction of the digital lines connecting our network with the University of Bologna.
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| February 19th 2002 |
- The pages dedicated to the DPOAE / TEOAE hardware devices offered by Starkey have been updated. Currents users of the DPOAE / TEOAE 2000 system should also consult the news voice of the DP2000 page for information regarding the release of new DPOAE software.
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| February 15th 2002 |
- The clinical section of the White papers has been updated with a contribution by Shanda Brashears, M.C.D., C.C.C.-A on the interesting topic of music induced hearing loss.To remind the reader that one of the very interesting aspects of using OAES in such cases is the fact that many people with years of noise exposure show normal behavioral pure tone thresholds but absent or reduced OAE amplitudes.
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| February 7th 2002 |
- We have appreciated the comments on the new section of Methods of TEOAE Signal analysis, and we expanded the information with data from various OAE classification methods.
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| February 3rd 2002 |
- The section on the screening programs from around the World, was updated with a report from the neonatal screening program from Athens , Greece.
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| January 30th 2002 |
- The TEOAE pages from the section on Basics of OAEs were updated. The new pages refer to "Methods of TEOAE signal analysis" and contain information on the latest methods applied on TEOAEs such as wavelets, time-frequency analysis, higher Volterra series and Recurrence Quantification Analysis.
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| January 28th 2002 |
- The section on OAE-Hardware was updated. Also MADSEN has announced a new lighter probe design for it's Echoscreen family of devices.
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| January 26th 2002 | |
| January 25th 2002 |
- If you haven't visited lately the Promenade 'round the Cochlea, the European Portal on Audiology and Hearing Science, now it is a excellent moment to do so. The site has converged to an educational and interactive tool (which is the current trend for most scientific Portals) and contents an excellent synopsis on OAEs.
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| January 19th 2002 |
- Editors Note:A number of visitors have asked us if it would be possible to start reporting the authoring activities from other countries, as we do with the Italian OAE-reality. Considering our present resources this is not a feasible possibility. But in order to enhance the dialogue within the OAE-community and to stimulate the generation of FORUMS we PROPOSE to any interested colleague who wishes to contribute to the authoring activities of his/her country, to start such a task and send us some initial results. For example it would be interesting to know the various working groups / per country and an email address of reference.
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| January 16th 2002 |
- We have been notified by a number of visitors that there is a British site containing info on neonatal hearing screening. To get more info click here.
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| January 14th 2002 | |
| January 12th 2002 | |
| January 9th 2002 |
- On the NCHAM web site you may find an excellent document on the American reality of neonatal hearing screening and it's practical implementation. The authors are two very well-known contributors to the neonatal screening field, Karl White Ph.D. and Antonia Marcia Maxon Ph.D. . If you are interested in downloading the document be aware that it is relatively large (1.641 k) and requires the Adobe pdf Acrobat reader. If you do not have it, you may download the FREE Adobe's Acrobat Reader from Adobe's Website.
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| January 8th 2002 | |
| January 2nd 2002 |
- Paul Avan Ph.D. and his equipe have send us a very interesting contribution titled "Cubic difference tones (2f1-f2) produced by high-intensity stimuli: their origin revealed by the combined effects of cochlear ischemia and auditory fatigue" which is listed in the biophysics section of white papers. Their paper is very interesting because their data are supporting the hypothesis that even in high-stimulus intensities the cochlear amplifier is active.
From the introduction to their paper we can read ".......Active / passive" models such as that coined by Mills (1997) assume that CDTs are the vectorial sum of two components, one from the "active" modality, that would be dominant in a healthy cochlea, and one from some "passive" modality that, although normally smaller, would be revealed at high intensities after the "active" component had faded out. The "passive" modality has remained elusive so far: it could arise from entirely "passive" mechanisms per se, such as basilar membrane or inner hair cell motion, or originate from the same nonlinearity as "active" CDTs except that it would come from other places than that tuned to f2. The "active / passive" model has gained popularity by successfully predicting several yet unexplained phenomena, such as the sharp notches occurring in CDT growth functions, or the ones observed along the course of cochlear ischemia or furosemide poisoning: such notches are to be expected whenever the "active" and "passive" components happen to have the same amplitudes and be out of phase. Indeed, the CDT phases (after vs... before the notch) present 180° differences in the case of furosemide (Mills and Rubel, 1994), though not in that of ischemia (Mom et al., 1997, 2001). Besides, Lukashkin and Russell (1999) have designed a single-component model of CDT production that predicts notches despite the absence of a second "passive" modality, by means of letting the operating point of the nonlinear device at the origin of CDTs move with stimulus intensity (which Frank and Koessl had achieved experimentally with similar results in 1996). The argument is more than an academic one because the existence of "passive" CDTs would jeopardize the whole CDT-based screening procedures: most commercial equipment propose default stimulus intensities in excess of 60 dB SPL for the sake of signal-to-noise considerations"..... To read the rest of the paper click here
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| January 2nd 2002 |
- For the first entry of 2002, we are pleased to announce that the TEOAE pages of the OAE Basics have been updated and expanded to include more topics and more clinical suggestions.
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