Unusual Hearing Aids

Varibel is a Dutch invention, invented in 2006

I came across  this interesting news while I was browsing, it's about hearing aids generally but more on variation of hearing aids specifically.  The title tells it all.

a. Varibel - the glasses that hears

These hearing device is specially designed for the elderly population - free from aesthetically unpleasing and technologically limited traditional hearing aids. The special feature of this hearing aids is in term of its directionality. If conventional hearing aids can offer maximum directional sensitivity of + 4.0 dB, this invention could cater up to + 8.2 dB. Testimonials from users claim that they could hear speech better in noisy event such as in birthday party. The device has four interconnected microphones on both of its frame legs, which selectively intensify sounds from the front (desired sound) while dampening surrounding noise (unpreferable background noise).

b. Disposable Hearing Aids ?

Have you heard of Insound Medical Lyrics ? It is a deep fitting dispobale hearing aids. It's neither a middle ear nor a cochlear implant, it is just fitted at a closer proximity to the eardrum. Previously, the fitting was eligibily done by the ENT specialist only, but now audiologist can do it too.This design has unbeatable cosmetics and improved sound quality as it is claimed to be free from distortion due to wind noise. Deep placement in the canal allows natural sound perception.The device also offers easier phone use.Lyrics is disposable after the battery ceases within 120 days. No removal is needed till the battery die and so listening 24/7 is possible! Use it during shower, exercise or even sleeping! 

3. Solar Power Hearing Aids


 Towards eco-friendly and cost-efficient product, this invention brought hope for hundreds of people in developing countries.American Academy of Audiology has awarded the Humanitarian award for Solar Ear, a Brazil-based company.This is a good news for people with low income or for those who are living in places with unreliable electrical supply.

Dead Region - Gives Valuable Information

Evaluation for the dead region is becoming a hot topic in the field of audiology. Have you heard of TEN test ? TEN stands for Threshold-Equalizing-Noise test, and the application of this test is getting more recognized as it is already available in some audiometers such as Affinity2.0 & Equinox2.0 PC-based Interacoustics audiometer. Previously, this test has been conducter via audiometer connected to compact disc player. The main function of this test is to identify the dead region in cochlea.

Wait a minute - What is Dead Region ?

Dead region consists of non-functioning Inner Hair Cells (IHC) or neuron, causing 'holes in hearing' . Well, IHC plays important role in stimulating the auditory nerve and so their loss may lead to abnormally large vibration of basilar membrane. Even so, the vibration can't be detected by the neurons connected to the particular region! So if a high frequency tone presented to the dead high-frequency region, the vibration will not trigger neural response over that region. Anyway, there is chance for 'off-place listening' when the vibration is sufficient enough to stimulate basilar membrane region near apical region (lower frequency region). Then, the high tone is heard as a lower frequency sound.

Note the difference, in Outer Hair Cell (OHC) damage alone, vibration of basilar membrane for a low-level sound will be reduced, anyway the intesity of vibration is restored with louder sound.

TELLSIGN - any hearing loss of above 70 dBHL is often associated with dead region, but of course normal puretone audiogram can't confirm this condition.


Figure shows dead region or 'holes in hearing' in cochlea derived from a young man who was exposed to gunshot before dying.

Source :http//://www.hearingreview.com/issues/articles/2010-01_01.asp


What is the sense in TEN ?

The test involves detecting threshold of a puretone in presence of background noise. For those who are interested, please refer to http//://www.hearingreview.com/issues/articles/2010-01_01.asp

The idea of this test is the signal threshold will be higher than normal in cases with dead region, in presence of noise. The masked threshold will be at least 10 dB above the absolute threshold 10 dB above the nominal noise level.

How will this be helpful for me?

Identifying the dead region could help us in making some important decision, especially when it come to the mode of amplification. For instance, a patient with dead high-frequency region, could possibly benefit from hearing aids with frequency transposition function and does not unnecessarily requires high-frequency (>1700 Hz) amplification which may lead to problems such as distortion and acoustic feeedback.

Patients with dead low-frequency region do not need emphasis on low-frequency amplification (< 0.5 k Hz), as this can further reduce the speech inteligibility.

If your patient is a candidate for Hybrid, TEN test might be helpful in determining the edge frequency of dead region, to assist in deciding the depth of electrode insertion.


In summary, understanding the physiology of hearing loss thoroughly will help us in implementing the most suitable amplification and rehabilitation management for our patients. It also prevent unnecessary hassles to both professional and patients.

Wireless Hearing Aids - A Challenge Between Technology and expectation

Wireless hearing aids have become a hot topic in the world of hearing amplification. Most manufacturers are bringing up this feature in their medium and premium products. Technology is expanding tremendously with years, but speaking about compressing sophisticated technology into miniature device, is rather a challenge! Bluetooth receiver chips ain't small in size! The truth is this wireless capacity needs extra space and power consuming. Therefore, bringing up a discreet product with wireless feature itself is already a good attempt.


Wireless feature is not only limited to input signal to overcome the effect of noise, distance and reverberation such as in supporting direct communication with cell phone and television. It also enables data exchange between two hearing aids, worn on both sides of the ear. This function is viewed as a key towards binaural processing in emphasizing on natural hearing experience.

Current market offers several wireless technology. For example :

- e2e wireless technology by Siemens.

- 2.4 GHz wireless technology by Beltone (True hearing aid) and GN Resound (Alera hearing aid)

- InterEar wireless solution by Widex (Clear hearing aid)

- CORE (Communication Optimized Real-audio Engine) technology by Phonak (iCom interface)

- RISE technology by Oticon (ConnectLine interface, EarStream for binaural connection)

- IRIS wireless technology by Starkey (Surflink interface)

- Unifi wireless system by Unitron

Despite of the challenges, manufacturers are trying to produce tiny hearing aids with excellent sound quality, low power consumption,broad connectivity and no ruining interference from other wireless devices. Beltone's product manager had mentioned that higher the frequency-based wireless transmission enables larger data transmission and so helping in improving the sound quality.