Hearing in early old age: current perspectives

Abstract

Age related hearing loss is a public health concern that restricts the possibilities of older persons to lead a healthy, social and active life. The present thesis aims to provide contemporary perspectives on age related hearing function and hearing loss in the general population, in early old age. The thesis is based on data from the Gothenburg H70 Birth Cohort Study, a prospective epidemiological investigation of ageing, in which representative segments of the older population are examined with a wide-ranging test protocol covering multiple aspects of health. The four papers, on which the thesis is built, examine various hearing parameters in a recent birth cohort of 70-year-olds, born in 1944. The results from Paper I demonstrated that the prevalence of hearing loss has decreased significantly among 70-year-olds in Gothenburg, across a time period of nearly five decades (1971-2014). Reductions in exposure to occupational noise is probably one of the most important factors explaining the findings. In Paper II, auditory function was investigated in detail based on a comprehensive audiological test battery performed in a subsample. The results demonstrated that cochlear pathology is the predominant cause of hearing loss at age 70, but that early neural ageing is present, leading to poorer speech recognition in some individuals. In Paper III, a comparison was made between automated and conventional pure-tone audiometry in 70-year olds and 85-year olds (born in 1930). The results indicated that automated pure-tone audiometry is a valid test method in the majority of older persons, and that age, hearing loss and cognitive status did not affect the outcomes. Finally, in Paper IV it was demonstrated that poorer hearing is associated with poorer cognitive function, but only when considering pure-tone and speech measures, and not self-report. Hearing aid use was associated with better cognitive scores. In conclusion, hearing loss - of various underlying pathology - is a prevalent condition in early old age that is associated with poorer cognition. Given the rapid ageing of populations in Sweden, and worldwide, efforts of prevention, early identification and rehabilitation of age related hearing loss should be considered a public health priority.