Part IV Hearing Health Hearing Aids, Cochlean Implants, and Hearing Protection

Hearing aids are never as good as perfect hearing. However, there have been dramatic improvements in technology. In general, it is possible to find a very satisfactory, appropriate hearing aid for individuals as long as there is some residual hearing (not total deafness). Selecting a proper hearing aid requires skilled evaluation, and testing with numerous devices and electronic adjustments. Door-to-door salespeople do not ordinarily have the capabilities to perform such testing and should generally be avoided. Reputable hearing aid dealers, audiologists, speech and hearing centers, and some ear doctor offices dispense hearing aids. Any reputable hearing aid dispenser offers a 30 day return period, during which the hearing aid can be brought back for a refund if the user finds it unsatisfactory. Hearing aids vary greatly in style and cost. Some fit almost entirely within the ear and are nearly invisible. A larger hearing aid that fits behind the ear may be necessary.

Occasionally, for extremely severe hearing losses, old-fashioned “body aids” with a wire are still used; but it’s only required in a very small minority of patients. Digital hearing aids are now available and used routinely. For many people, they really do offer substantially improved sound quality and digital programming options that make it easier to hear with noise. Selecting a hearing aid is a very personal process, and it is essential that any potential hearing aid user have the opportunity to listen to a variety of instruments adjusted expertly before making a selection. Hearing aids can be worn on one or both ears depending upon the hearing loss, and there are even CROS (contralateral routing of signals) aids for total deafness in one ear, in which a microphone is placed on the deaf side and it transmits sounds by radio signals to the good side. This is a great convenience for many people who have to function in meeting rooms. It is also extremely helpful when driving. For example, a person driving with a deaf right ear has trouble hearing a passenger, especially if the driver’s window is open.

A cochlear implant is a device that restores hearing to people with very severe or profound deafness. Cochlear implants have been used in humans since the late 1960s. It is a safe electronic device that is implanted beneath the skin and into the inner ear. (In rare cases, the device can actually be implanted directly into the brain). Once the outer skin has healed, an external device is placed on the skin over the implanted decide and turned on. Cochlear implants allow totally deaf people to hear common sounds such as a telephone, doorbell, car horn, and spoken voice. In most patients, understanding of speech is not wonderful, but speech reading is improved dramatically by the ability to hear the rhythms and the stops in normal speech. In a small minority of patients, good understanding ability occurs. Until very recently, cochlear implants were approved for use only in people with profound (total or near deaf total) deafness. However, in 1995, the FDA approved expanded indications to include people with severe hearing loss and decreased discrimination of 40 percent or less. This change was consequent to an 8-year study that showed cochlear implant patients get better hearing than with traditional hearing aids prescribed for people with hearing loss this severe. 

A comprehensive discussion of ear surgery is beyond the scope of this discussion. However, ear surgery is extremely common and is generally safe and effective when performed by an expert surgeon. Certain operations are particularly common.

Common surgical procedures include myringotomy and tube placement for eustachian tube dysfunction, eustachian tube dilatation to help the eustachian tube work better and avoid the need for tubes, tympanoplasty to repair perforations in the eardrum, stapedectomy to restore hearing in patients with otosclerosis, implantation of bone-anchored hearing aids, mastoidectomy for chronic infections or growths such as Cholesteatoma, surgery for cancer and many other procedures. Your operations are extremely common. Some are performed under local anesthesia with sedation (awake), and others are performed most commonly under general anesthesia. All ear surgery include risks (worse hearing loss, tinnitus, dizziness, facial paralysis, recurrence of the ear problem, infection, bleeding, and others), but adverse events are uncommon. Your surgery in expert hands generally is safe and effective.

Translabyrinthine surgery (through the inner ear) for removal of acoustic neuromas provides excellent access to the tumor with the best chance of preserving facial nerve function and totally removing the tumor in many cases. This approach involves a mastoidectomy extended through the inner ear labyrinth to enter the brain cavity.  However, it nearly always results in total loss of hearing. In most cases, the tumor has caused a significant hearing loss; and total tumor removal is not possible without removing the roots of the tumor embedded in the hearing nerve thereby necessitating the loss of hearing in order to cure the tumor. This approach has many advantages, including minimizing trauma to the brain. However, any acoustic neuroma surgical team utilizes translabyrinthine surgery in combination with other approaches, depending upon the anatomy of the tumor and the needs of any individual patient.

Neurotologists also perform extensive skull base resections (procedures that take about 24 hours) for cancers of the skull base and ear-brain interface. These operations are formidable but may be life-saving.

Preventive medicine is always the best medicine. It is important to protect the ears from excessive noise exposure. Even when mowing the lawn or using a power saw, ear protectors should be worn. The advice of a physician or trained and certified audiologist is often helpful in selecting appropriate ear protectors. Pieces of cotton or paper towel (or spent bullet casings) stuffed in the ears are generally inadequate. It is important to be aware of recreational noise sources, including music. With personal portable music systems, if the person standing next to you can tell what you are listening to through earphones, the music is probably too loud. We commonly encounter incurable cases of tinnitus and high-frequency hearing loss caused by the use of these devices. They need not be avoided, but “common sense” should govern their use.

Having reviewed many (but certainly not all) of the health problems that may adversely affect the ear, it is clear that maintenance of good general health is important to the ear as well as to the rest of the body. Maintaining appropriate blood pressure, healthy eating and exercise habits, and close surveillance on bodily health (such as annual physical examination) are extremely helpful. If there is reason to suspect hearing loss such as with a strong family history, hearing tests should be included in the physical examination so that hearing problems can be recognized and addressed early.

Like so many other things, we never appreciate the value of hearing until it is lost. Through sensible preventive measures, many potential causes of hearing loss can be eliminated. When hearing loss occurs, its progression can sometimes be prevented or slowed. In every case, early diagnosis and optimal management minimize the psychological and social trauma so common in people with hearing impairment. Maintaining contact with a physician specializing in hearing is wise for any patient with hearing impairments. Apart from all the things we have learned in the last decade or two, hearing experts are constantly working to learn more about the conditions we don’t understand, yet. Even for patients, we can’t cure today, there is always hope for tomorrow.

SUGGESTED READINGS:

Sataloff RT, Sataloff J: Hearing Loss, 3^rd Edition, Marcel Dekker, Inc., New York, NY, 1993.

Sataloff RT, Sataloff J: Occupational Hearing Loss, 2^nd Edition, Marcel Dekker, Inc., New York, NY, 1993.

REFERENCE:

1. A.T. Rasmussen, Outlines of Neuro-Anatomy, W.C. Brown, Dubuque, IA (1947).