Scandinavian audiology. Supplementum
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Review
Genetic influences on susceptibility of the auditory system to aging and environmental factors.
Auditory susceptibility to aging and environmental factors (noise and toluene) was investigated in two genotypes of mice, CBA/Ca (showing a moderate hearing loss with onset late in life) and C57BL/6J (undergoing spontaneous auditory degeneration with onset during young adulthood). Both strains of mice were often used together as a model of human age-related hearing loss, with a primary decline in auditory high-frequency sensitivity. Auditory function was analysed by recording auditory brainstem response (ABR). ⋯ First an additivity and then, at total threshold shifts of 30-50 dB, a blocking-like interaction were observed. The rate of progression in post-noise hearing loss did not exceed the spontaneous rate of age-related degeneration. The difference between exposed and non-exposed groups decreased with advancing age for both strains of mice.(ABSTRACT TRUNCATED AT 400 WORDS)