Hearing Aids and Otosclerosis

Patients suffering from otosclerosis usually have a conductive hearing loss with good bone conduction, as well as excellent speech discrimination scores. Such patients with conductive-type hearing losses show excellent benefit from amplification of sound.

How severe should a conductive hearing loss be and still be classified as a purely conductive hearing loss? Reger (1940) indicated that for a hearing loss to be purely conductive, it could attain a maximum gap of 60 dB. Beyond that, he concluded, a sensorineural component was inevitable. Pohlman (1943) published a report on 10 patients who had undergone complete removal of all middle ear structures. Those patients averaged a pure conductive hearing loss of 58 dB.

SITUATIONS APPROPRIATE FOR HEARING AIDS

Most patients with otosclerosis have severe conductive hearing losses that are accompanied by a sensorineural component. Typically, patients have a good to excellent speech discrimination score despite the severity of the conductive hearing loss.

Amplification via hearing aids or assistive listening devices must be presented to patients as viable alternatives to surgery (Johnson 1993). Not only are there medicolegal responsibilities in presenting these alternatives, but there are also many patients who may be adequately managed with amplification. Situations that are appropriate for hearing aids include the following:

1. Patient cannot undergo surgery because of major systemic illnesses.

2. Only hearing ear

3. Patient has inadequate hearing reserve and/or poor speech discrimination score.

4. Congenital fixation of the stapes is present, with the real risk of it developing into a nonhearing ear if surgery is contemplated.

5. Surgery is not elected by the patient.

6. Affected ear shows early (mild) conductive hearing loss.

8. Patient has both otosclerosis and Meniere’s disease.

9. Patient has stapedectomy for far-advanced otosclerosis.

It is important to assess the patient’s communication needs and difficulties. It must be remembered that indications for amplification in patients with conductive hearing losses are different from candidacy criteria for those with sensorineural hearing losses because of the difference in loudness perception at comparable sensation levels. A mild conductive hearing loss may affect communication more than a mild sensorineural hearing impairment with recruitment. Patients who have a conductive hearing loss will need more amplification to achieve comfortable listening levels than those with sensorineural hearing impairment. The conductive hearing loss creates a higher tolerance for loud sounds, producing a wider dynamic range that is reflected in greater saturation sound pressure levels.