A number of treatments have been prescribed for the condition, ranging from the most conservative (dietary) to the most extreme (sectioning the vestibular nerve). Recently, another conservative option has been introduced, the Meniett Low-Pressure Pulse Generator.
People who have Meniere's disease know it. The disorder is usually characterized by sudden attacks of vertigo, often accompanied by nausea and vomiting, a sensation of fullness in one ear, tinnitus, hearing loss, and more difficulty in speech discrimination that would be expected on the basis of the audiogram alone. Most often just one ear is involved. Gradual improvement in vertigo occurs about 70 percent of the time though some degree of hearing loss may remain. Anybody who has, or suspects that they have this problem, should definitely be under a doctor's care.
Most authorities believe that the condition is caused by either an overproduction or underabsorption of the fluid (endolymph) that bathes the central duct of the cochlea (the scale media). This channel is the place where the hair cells are located, the delicate sensory structures that convert sound energy into electricity. The excess of the endolymphatic fluid (hydrops) damages the hair cells and causes the hearing loss and tinnitus. And since this fluid also connects to and bathes the nearby vestibular structures that control a person's sense of balance and equilibrium - the semicircular canals, saccule and utricle - its excessive build-up stimulates the sensory cells in this region and produces the sensations of vertigo and nausea.
A number of treatments have been prescribed for the condition, ranging from the most conservative (dietary) to the most extreme (sectioning the vestibular nerve). Recently, another conservative option has been introduced, the Meniett Low-Pressure Pulse Generator. According to the company, the device has been shown to be effective in several randomized, placebo controlled, published studies. One such study showed reduced vestibular symptoms in 31 subjects compared to 25 for whom there was no change in the incidence and severity of nausea and vertigo. Another study demonstrated improvements in vertigo for all ten subjects participating in the study. Some small amount of hearing benefit was also observed for a few of the subjects.
What the Meniett device does is deliver a controlled series of low-pressure air pulses to the round window membrane leading to the cochlea. (The cochlea has two windows on the far surface of the middle ear: the oval window into which the eardrum and middle ear bone vibrations are directed, and the round window that works in tandem with it. That is, when the oval window is pushed in by the sound energy, the round window is pushed out and vice-versa.) The theory is that the energy of the pressure pulses on the round window displaces the inner ear fluids. leading to an increased flow of fluid within the entire endolymphatic system. Somehow, and this is not made too clear, this action is supposed to reduce the pressure and thus alleviate the symptoms of Meniere's disease. From the point of view of people with Meniere's disease, however, I suspect that they would be much less concerned with knowing how it works as long as it does work.
Treatment with the Meniett device consists of two phases. In the first one, a myringotomy is performed and ventilation tube is inserted through the eardrum. This is exactly the same procedure routinely performed by ENT physicians in treating certain middle ear infections. The small slit in the eardrum soon heals after the treatment and when the tube is extracted. The reason for the ventilation tube is to permit the sound pulses generated by the Meniett device to directly impinge upon the round window membrane without interference by the eardrum.
In the second phase, the patient is instructed how to place the ear-cuff connected to the Meniett device within the ear canal so that it completely seals the opening of the canal, The device itself is rather small, about five by seven inches, and the patient administers the procedure to him or herself at home (after being instructed in its use by the physician or an audiologisti. When the device is switched on, it presents a programmed series of air pulses into the ear canal through the eardrum and into the middle ear. The stated treatment time is three times daily for three minutes each time. The length of time varies depending upon the results of the therapy. The Meniett treatment must be monitored by an otolaryngologist or by somebody who works (probably an audiologist) under that person's supervision.
InSound XT Hearing Aid
by Mark Ross, Ph.D.
InSound Medical has introduced a new hearing aid with several unique features.Unlike all other hearing aids this one requires the services of an otolaryngologist who uses an operating microscope to insert the aid deep into the ear canal. The reason a physician is needed is to ensure that the ear canal is completely healthy and clean of any kind of debris. The fitting is done in collaboration with an audiologist who adjusts the electroacoustic parameters of the hearing aid. The microphone is located in the midpoint of the ear canal, while the receiver (the loudspeaker" of the aid) is placed about three millimeters away from the eardrum. The aid comes in pre-packaged sizes and fits about 70 percent of the ears that it has been tried on. It is intended only for people with mild to moderately severe hearing loss.
According to Dr. Robert W. Sweetow, director of audiology at UCSF, the device overcomes the "hollow sound" experience that often occurs with more conventional hearing aids as well as eliminating acoustic feedback. He reports that the aid is truly invisible, comfortable (when properly fit) and basically "hassle free." What is unique about this hearing aid is that it is designed to be worn continually for about four months. Once inserted in the ear canal, the user is expected to forget about it. It can be worn 24 hours a day in all circumstances Lwhile sleeping, taking a shower or bath, swimming, etc.). At the end of the four-month period, or when the battery is dead, the aid can be removed by the user and new aid is inserted in the ear canal (again. by a physician).
I do not have any specific information regarding cost, but the informal feedback I did get suggests that long-term usage will likely cost a user somewhat more than the most expensive digital hearing aid. In other words, people who want to wear a hearing aid that is truly invisible will have to pay a "vanity" surcharge. Other use and acoustic advantages are not unique to this hearing aid.
There is no published information regarding how well people actually hear with the hearing aid. Anecdotally, it appears that people will hear at least as well with the lnSound XT as they would with many other modern hearing aids. At the time of the current writing, the aid has not yet been introduced on a widespread scale.
According to the company, the reason for the extended battery life is the inclusion of "an ultra low-power chip which requires less than 10 percent of the energy of conventional hearing aids." This is an impressive development, one that I hope will soon find its way in 'conventional" hearing aids. Any aid that can be worn for four months, 24 hours a day without a battery change (or aid replacement in the InSound case) presents an advantage that all people who wear hearing aids would like to benefit from.
Solar-Powered Hearing Aid
by Mark Ross, Ph.D.
Another unique solution.
We all know that hearing loss is a world-wide phenomenon. It occurs in both rich and poor countries, but even more so in the latter because of inadequate health care. We also know that both the medical and non-medical management of hearing loss is often limited in poorer countries and regions because of inadequate health and special education services. This became very apparent to me a few years ago when I was asked to review a World Health Organization (WHO) document intended to help people understand and deal with hearing loss in third world countries.
In this well-intentioned, and basically valuable document, a foldout page was included that was designed to be shaped into an ear horn. Surely, I thought we should be able to have better 'amplification" alternatives for people with hearing loss than ear horns! While low-cost sound amplifiers were and are available - not quite hearing aids but better than a cardboard ear horn - the problem of ensuring affordable batteries remained an obstacle. Recently, a company in Botswana (Godisa) has come up with what looks like a solution to both the hearing aid and battery problem with the development of a solar-powered hearing aid. According to reports, the company is the only manufacturer of hearing aids on the African continent
Their behind-the-ear hearing aids (one moderate power and one high power) appear to be conventional analog hearing aids, of the type used frequently in the United States until quite recently. It includes a telecoil, tone control, and rechargeable batteries. These aids do not include sophisticated signal processing features found in our modern analog or digital hearing aids. On the other hand, there is no doubt that most people with hearing loss can realize significant benefit from these aids (as many of us did with comparable aids for a lot of years).
It is the Solar Charger that appears to be the unique and creative product of this company (see figure). It comes with two AA rechargeable batteries. When the unit is placed in the sun, these batteries can be fully charged in about five hours. At night, it is the power from the AA batteries that charge the hearing aid and additional battery (ensuring that the user always has fully charged batteries available). Even if there is no sun for a few days, the re-charger can still be used according to the company, as the AA batteries maintain their charge for nearly a week.
The whole point of this unit is to provide a low-cost alternative to high-price batteries in developing and poorer regions of the world. From the information I have received, it seems that this unit has succeeded in doing just that. The general manager of the company tells me that the Solar Charger (which comes with the rechargeable AA and hearing aid batteries) is priced low enough (about $20) to be affordable in third world counties. She also states that the company's mission includes employing and training people with disabilities. Seven of their nine employees are either deaf or physically challenged. Further information about the company and its products can be obtained by writing: mwb@info.bw
Speech View
by Mark Ross, Ph.D.
Speechreading is a difficult task at best. Here is something that might help.
Developed in Israel, Speech View is a software program that converts acoustic speech signals received by a cell phone to a visual display via a computer connection. The program translates the voice signals into a three-dimensional, animated cartoon-like face whose lips move in real-time synchronization with the voice. There is no language restriction since the software analyzes the phonemic constituents of the speech signal and converts these to their visual equivalents (or visemes).
Speechreading is a difficult task in the best of circumstances, since so many of the sounds of speech look the same on the lips. According to the developers, the SpeechView program handles this by providing additional visual clues to differentiate sounds that look alike. For example, the sounds (phonemes) /b/, /p/, and /m/, all look alike on the lips. In this instance, there would be a mark on the throat for the voiced sounds (/b/ and /m/) and on the nose for the nasal phoneme /m/. Plosive sounds (such as /p/) are marked by a circle on the cheek of the facial image.
A successful speech reader will utilize all information available in order to better comprehend a spoken message (facial expressions, body stance, linguistic predictability and, of course, sound). Users of Speech View can take advantage of as much acoustic information as their hearing loss permits. The spoken message can be heard through the computer, synchronously with the visual animation. Users can also talk back because the program puts the cell phone in the loudspeaker mode and the phone will transmit voice signals back to the other party. As described, it seems like a voice carry-over (VCO) connection, where the person with a hearing loss but good speech can talk directly to the other party. While using the visual mode for reception (in this case. the animated face rather than the printed word).
The developers emphasize the need for training to improve a users skills with the SpeechView program. An instructional manual is included with the program. As described, SpeechView seems a bit like cued speech. where lip movements are disambiguated by hand signs around the mouth. Of course. with cued speech. face-to-face communication is required, a limitation not relevant with this program. And since we know that training can help people learn cued speech. perhaps the same will also be true of the Speech View program. As of yet, I am aware of no independent studies that have evaluated the efficacy of Speech View. Further information can be obtained by emailing sigal@svu.co.iI.
Mark Ross, Ph.D., is the former director of research and training at the League for the Hard of Hearing, and an associate at the Rehabilitation Engineering Research Center (RERC) at the Lexington Center, New York. This column is supported, in part, by GRANT #H I 33E9800 10 from the U.S. Department of Education. NIDRR, to the Lexington Center. Mention of products or companies by the author does not indicate SHHH endorsement, nor should exclusion suggest disapproval. Since everyone's communication problems and needs vary, SHHH suggests consulting with your hearing health professional.