ABSTRACT

The history is helpful because it is distinctive in two notable causes of sensory hearing loss: noise-induced hearing loss and Meniere's disease. The patient with noiseinduced hearing loss generally will volunteer the information that the hearing loss and ringing tinnitus started after exposure to gunfire, exploding firecrackers, or industrial noise. In Meniere's disease, the hearing impairment usually will be unilateral and accompanied by ocean-roaring, or seashell, tinnitus and a feeling of fullness in the ear. Vertigo may or may not be a feature, and this as well as the hearing loss will be intermittent at first, though later it may become persistent. Many patients with Meniere's disease, even when it is unilateral, will not say that they do not hear, but they will complain that they are unable to distinguish the exact words they hear. Bath sounds like path, bomb like palm. This indicates a reduction in discrimination. Along with this, they will say that speech and sounds are distorted and irritating, especially if loud. A baby's cry may sound unbearably loud. (This indicates a lowered threshold of discomfort due to recruitment, although hyperacusis may produce a similar complaint.)

According to most authorities on Meniere's disease, this disorder is characterized by a pathological change in the endolymph, which then affects the hair cells. This causes damage which at first is temporary and reversible but later results in permanent damage inside the cochlea, and, ultimately, degeneration of the auditory nerve fibers takes place, making the final result a sensorineural hearing loss.