Diplacusis: II. Etiology

DIPLACUSIS may be congenital as seen in "tone-deaf" people, or acquired when due to allergy, trauma, infection, toxin, and neoplasm. Provocative food testing will often elicit diplacusis which can be improved by a strict allergic regimen. Trauma may vary from the din of a discotheque to a direct blow to the head or to iatrogenic injury. Infection may be indirect as with a focus in septic tonsils or direct pressure on the oval or round windows in a suppurative otitis media. Toxic factors include: aspirin, quinine, streptomycin, kanamycin, carbon monoxide, and excessive sodium intake. Leukemia, with associated cochlear hemorrhage or acoustic neurinoma, with initial "coagulum" effect, are neoplastic causes of diplacusis. Cochlear dysharmonics result from physical, chemical and bioelectric effects of anoxia, vasopasm, edema, abnormal capillary permeability, hemorrhage, exudate, and viscosity changes. Capillary fragility can be easily tested using the vacuum-cup method with graduated suction of 10 to 20 or