Hearing in increasing age. Epidemiological and psychoacoustic aspects

Abstract: Presbyacusis, age-related hearing decline, is the most common cause of hearing impairment in the more developed countries. Planning of health services for the hearing impaired requires knowledge of hearing in increasing age and in demographic changes.The prevalence of self-reported hearing difficulties in the adult Swedish population was studied in respect to age, gender, regional and socioeconomic code. Longitudinal, time-lag and cross-sectional approaches were used to evaluate hearing deterioration in an elderly population sample. Aspects pertinent to pure-tone audiometry, directional hearing and speech recognition in noise were analysed. As part of the Investigation of Living Conditions performed by Statistics Sweden 1986-1993, 48680 randomly selected Swedes aged 16-84 years answered a question concerning the ability to hear a conversation between several persons. The deterioration in pure-tone audiometric thresholds was evaluated in elderly aged 70 and 75, and oldest olds aged 85, 88 and 90. Speech recognition performance in noise was studied by a new method in 73- and 80-year-olds. The ability to localise sound was examined in an elderly group of 75-year-olds. In the adult Swedish population, 10.7% reported hearing problems, with a prevalence increase from 2.4% in the youngest to 30% in the oldest group. Higher prevalence of hearing problems was associated with age, male gender, blue-collar work or unemployment, and domicile in less urbanised regions. Pure-tone audiometric thresholds declined between age 70-75, predominantly at 2-4 kHz for men, and 4-8 kHz for women. A decline in pure-tone thresholds was found up to 90 years of age, with a greater mean annual deterioration in the 8th compared with the 9th decade. Speech recognition performance in noise decreased significantly between the age of 73 and 80. There was a strong association between speech recognition ability and pure-tone thresholds. Directional hearing was significantly poorer in 75-year-olds compared to younger controls. A large variability in performance was the rule in all testing procedures.Conclusion: An increasing prevalence of self-assessed hearing disability, and impairment of hearing sensitivity, speech recognition and sound localisation was found in increasing age. Demographic and epidemiological studies are of importance in monitoring the development and effect of hearing problems in populations.