Robert Sweetow, PhD, director of the clinic, said the devices are manufactured by Songbird Hearing, Inc. of Princeton, N.J. and will be available to patients in the study later this fall. Although the manufacturer has market test sites in other parts of the country, UCSF is the only site where research is on-going that will compare the disposable aids to conventional hearing aids.

Sweetow explained that these "one size fits all" devices are designed to fit entirely into the ear canal. "In reality," he said, "they actually fit 70-80 percent of adult male ears and about 50 percent of adult female ears. The instruments have a very soft 'mushroom' cap that fits about half way into the ear canal. This relatively deep placement accomplishes two goals. It produces a very good acoustic seal that minimizes feedback or whistling, and it may help to reduce the common complaint that the user's own voice sounds as if he or she is speaking in a barrel."

The disposable devices last from 30-40 days at which time the encapsulated battery expires. At this point, the user simply disposes of the old one and replaces the device. With the ease of dispensing the disposable hearing aid, it is hoped that the 20 million Americans who need hearing aids but are not wearing them will evaluate the use of these new devices. Studies from the National Council on Aging have found that hearing impaired individuals who do not seek treatment are at risk not only for social isolation, but also for increased stress that can translate to stress-related illnesses.

There are several potential advantages to disposable hearing instruments, Sweetow said. Because of their short life expectancy, mechanical and electrical breakdown or blockage with earwax is not as likely compared to available hearing aids. If there is earwax blockage, the instrument can be returned to the audiologist or simply replaced. Another major advantage is that as technology continues to improve, the instrument won't become obsolete.

Hearing aid wearers can find it disheartening and a financial burden to spend thousands of dollars on new devices only to discover that six months later a better instrument becomes available, he said. With the disposable hearing device, there are no additional costs such as battery replacements, repair and maintenance or insurance. Finally, there is the advantage that patients can go to the audiologist and be fitted with hearing aids during the same visit.

According to Sweetow, the quality of the sound produced by these instruments seems quite good, but these new disposable hearing aids have yet to be formally evaluated while the current analog and top of the line digital hearing aids have been evaluated.

The UCSF study will be conducted with individuals currently wearing conventional hearing aids. The researchers will investigate several aspects of disposable hearing instruments: comfort, ease of use, subjective impressions of the sound quality, and ability to understand speech immersed in background noise. The results will be compared to those obtained by the test subjects' own hearing aids.

"There are some potential disadvantages to the disposable hearing aids," Sweetow said. The instruments are not a custom-fit, so the actual physical fit may not be suitable for some ears and the flexibility of the acoustic programming is not nearly as great as attained by programmable and digital devices.

The disposable aids presently have seven possible "prescriptions" available to the audiologist. "One of the biggest concerns is that if these devices become available outside of professional channels, serious abuses may result," according to Sweetow. "For example, these instruments are meant for mild to moderate hearing losses only, and these aren't appropriate for everyone," he said. "If the hearing is not accurately assessed prior to programming by an audiologist, the wrong 'prescription' may be selected."

"Patients should be evaluated for possible medical contraindications or for possible related systemic disorders," explained Sweetow. "Furthermore, people hear in their brains, not simply in their ears." Professional counseling and auditory training are required to maximize the effectiveness of hearing aids, he said. If disposable hearing aids become available in drugstores, via mail order, or over the Internet, Sweetow is concerned that patients will not avail themselves of these essential professional services.

In comparison to the disposable hearing aids, the programmable and top of the line digital hearing aids cost between $1500 to $2500 for each aid with a typical life expectancy of three to five years. The consumer is likely to save money with the new devices, particularly over the first few years. However, Sweetow cautions that the value of hearing is extremely high, and "if the disposable instruments don't provide the quality of better devices, the sacrifice in quality of life for a few hundred dollars is simply not worth it."

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For more information or participation in hearing studies at UCSF, please contact the UCSF Audiology Clinic at 415-353-2101.

Note: If no author is given, the source is cited instead.

• Hearing Loss
• Disability

• Hearing Impairment
• Perception

• Acoustics
• Technology

• Hearing impairment
• Tinnitus
• Acoustics
• Battery (electricity)
• Service dog
• Auditory system