Re-exploring Bekesy or what...?
After over four decades since the Hungarian physicist, Georg von Bekesy was awarded the nobel prize for practical demonstration of the functionality of the human cochlea, the cochlea model he highlighted in his nobel lecture, will appear quite crude compared to that recently described by  Wittbrodt, Steele & Puria (Audiology and Neurotology 2006;11:104-112) from Stanford had just reported developing a physical model of the human cochlea.

Abstract: Advances in micromachining technology have provided the opportunity to explore possibilities of creating life-sized physical models of the cochlea. The physical model of the cochlea consists of two fluid-filled channels separated by an elastic partition. The partition is micro machined from silicon and uses a 36-mm linearly tapered polyimide plate with a width of 100 µm at the basal end and 500 µm at the apex to represent the basilar membrane. Thicknesses from 1 to 5 µm have been fabricated. Discrete aluminum fibers (1.5 µm in width) are machined to create direction-dependent properties. A 0.5 × 0.5 mm opening represents the helicotrema. The fluid channels are machined from plexiglas using conventional machining methods. A magnet-coil system excites the fluid channel. Measurements on a model with thickness 4.75 µm show a velocity gain of 4 and phase of 3.5 ∩ radians at a location 23 mm from the base. Mathematical modeling using a 3-D formulation confirm the general characteristics of the measured response.
 

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Coming Events of Importance to Otolaryngologists in Africa...
 

1. BRITISH ACADEMIC CONFERENCE IN OTOLARYNGOLOGY - Humanitarian Award, 2006. For Details click HERE

2. Annual West Africa College of Surgeons Conference, Accra, Ghana, Feb 2006.
3. Association of Paediatric Otolaryngologists of India 12th Annual Conference and CME in Paediatric Otolaryngology
   February 25-26, 2006; New Delhi, India
4. 8th International Otology Course of the Jean Causse Ear Clinic
   June 22-24, 2006; Béziers, France
5. 110th American Academy of ORL,Head & Neck Surgery Annual Meeting & OTO EXPO
   September 17-20, 2006;
   Toronto, Canada.
6. 42nd South African ENT Congress joint meeting with the British Association of Otolaryngology - Head & Neck Surgery
   October 29-November 1, 2006;
   Cape Town, South Africa.

         For more Worldwide otolaryngological events and conferences....Click Here

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Predicting the reliability of behavioural audiometry.....?       

If you are concerned about what to make of the variability of response obtained with behavioural audiometry, then you may be interested in this report by Han et al (ORL 2006;68:64-68) from China reporting that the auditory steady state response (ASSR) is a good tool to predict behavioral hearing thresholds.

Abstract: Objective: It was the aim of this study to explore the use of auditory steady-state response (ASSR) to multiple simultaneous stimuli for threshold estimation in young children. Method: The subjects consisted of 40 children, aged from 6 months to 5 years, with variant degrees of sensorineural hearing loss. Simultaneous tonepips (0.5, 1, 2 and 4 kHz) with an amplitude modulated at different rates from 77 to 103 Hz were presented to both ears by insert phones. All children were tested with ASSR and age-appropriate behavioral tests. Results: We found that (1) ASSR thresholds were usually higher than behavioral thresholds with a difference of 8-15 dB, (2) the behavioral thresholds were significantly correlated with ASSR thresholds (p = 0.000), and (3) there was a great difference between ASSR thresholds and behavioral thresholds found in a child with auditory neuropathy. Conclusion: Being objective, frequency specific and well correlated with behavioral thresholds, ASSR to multiple simultaneous stimuli was proven to be a good tool to predict behavioral hearing thresholds

 

 

What is the diagnosis?

• Parting Shot...
  If you have an interesting case to discuss or share with other Otolaryngologists all over Africa, feel free to email Me or at best go to otolaryngology in Africa blogsite and post your case
• Also, if you are among those who requested for a copy of DODA at the last ORLSON Meeting @ Port Harcourt, please take time to view the DODA - FAQ page, and expect your copy anytime now. The program has been mailed to you.
• An online video demonstration of doda is available at http://www.otolaryngologyinafrica.net/doda_video.htm  This video takes about 30 - 45 minutes to fully load on a broad band network the first time, but once fully loaded could be viewed over and over again
• It appears as if the website of ORLSON - http://www.orlson.org/  is no longer active or visible on the web! Please For a list of active web sites of otolaryngological societies in Africa, click HERE
• If you have anything you want to communicate with other Otolaryngologists - news, request, etc, feel free to email your communication to orl-mailer@ otolaryngologyinafrica.net. Your request will appear in member's page soon to be created.
• Reviewers wanted for otolaryngology news journals watch page. If you are an Otolaryngologist in Africa and will like to be our journal reviewer, please feel free to email orl-mailer@otolaryngologyinafrica.net

Till Next Week,

Biodun

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