4) Beagley H A: Audiology and Audiological Medicine, Oxford University Press, New York, 1981, pp 319-321
5) Uhlmann R F, Larson E B and Koepsell T D, et al.: Hearing impairment and cognitive decline in senile dementia of the Alzheimer's type. J Am Geriatr Soc 34: 207-210, 1986