Hearing Loss: Does Gender Play a Role?

, University of Washington Medical Center; , University of Washington Medical Center, Virginia Merrill Bloedel Hearing Research Center

Disclosures

Medscape General Medicine. 1997;1(2) 

In This Article

Presbycusis

Background. Presbycusis is the most common type of auditory dysfunction. The term presbycusis was first coined by Zwaardemaker in 1891 to describe age-associated hearing loss.[7] Age-associated hearing loss was unknown in ancient times, probably because of an absence of excessive noise and a short life span. Presbycusis is generally viewed as the sum of 3 categories of insults to the aging auditory system:

  • Age-related degeneration. This hearing impairment due solely to age per se. In modern industrialized society, this component of presbycusis is primarily a theoretical consideration. Studies of hearing capacity in isolated populations--such as the Mabaan tribe in southern Sudan,[8] elderly Jamaicans,[9] and the Todas of South India[10]--provide some confirmation of the existence of pure age-related hearing loss, but do not exclude the effects of dietary or genetic factors.

  • Socioacusis. This category defines hearing impairment due to "wear and tear," and is secondary to extrinsic, environmental causes such as occupational and recreational noise exposure.

  • Nosocusis. This category refers to hearing impairment due to intrinsic, biologic factors such as comorbid disease, diet, and personal habits such as smoking and alcohol consumption.

Histopathology. Based on morphologic and audiometric findings, Shuknecht[11] proposed 4 types of presbycusis:

  • Sensory presbycusis. This type is caused by hair-cell degeneration. The majority of affected cells are located in the basal coil of the cochlea. Audiometrically, sensory presbycusis is characterized by an abrupt high-tone hearing loss with relatively normal speech perception. This is the type of presbycusis caused by noise exposure.

  • Strial or metabolic presbycusis. This type is caused by degeneration of the stria vascularis. The degeneration is most pronounced in the middle and apical turns of the cochlea. Audiometrically, metabolic presbycusis is characterized by a flat pattern of hearing loss (ie, equal loss over all tones). This is the type of presbycusis caused by biologic factors.

  • Neural presbycusis. This type is caused by a loss of neurons in the spiral ganglion. Audiometrically, neural presbycusis is characterized by a loss of speech discrimination. Neural presbycusis is uncommon and will not be discussed further.

  • Conductive cochlear presbycusis. This type is caused by an age-determined degenerative process of the cochlear duct with associated lesions of the basilar membrane. Audiometrically, conductive cochlear presbycusis is characterized by a sloping hearing loss accompanied by a linear increase in hearing loss above 1000Hz. Like neural presbycusis, this type is uncommon and will not be discussed further.

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