Pure-Tone Threshold Description of an Elderly French Screened Population

Abstract

To describe the distribution of pure-tone hearing thresholds of a Caucasian population living in the south of France aged 70 years and older. To establish age- and sex-adjusted normative hearing thresholds based on results of subjects free of noise and ototoxic drug exposure and to compare them with hearing thresholds of exposed (E) subjects. Cross-sectional analysis of a longitudinal epidemiologic cohort study. Montpellier suburb, south of France. A total of 778 subjects 70 years old and older were examined. Noise exposure, ototoxic medication use, and medical history were collected. Hearing thresholds were obtained via pure-tone audiometry. After excluding patients with ear-related disease, 659 subjects were further analyzed (270 men and 389 women). Noise or ototoxic medication exposure was found in 364 subjects (E subjects), whereas 295 had no exposure (nonexposed [NE] subjects). Median pure-tone thresholds, lower deviation, and upper deviation were calculated for the NE subjects with a statistical method similar to the ISO 7029 norm and were compared with thresholds of E subjects. Hearing thresholds, especially in high frequencies, increased with age more for women than for men. Median thresholds of E subjects were significantly higher than those for the NE sample in men. Age- and sex-adjusted hearing thresholds could well be useful in the study of the impact of environmental and genetic factors on hearing loss in the elderly. The next step would be to quantify the impact of noise, ototoxic drug exposure, and genetics using these age- and sex-adjusted thresholds.