The relationship between extra-high frequency hearing and cardiovascular endurance in noise exposed industrial workers

Extra-high frequency audiometry may have an important clinical use as an indicator of the traumatic effects of noise (Sataloff et al., 1967; Fausti et al., 1981b). A relationship between extra-high frequency hearing and the state of the cardiovascular system was postulated by Rosen and his colleagues (Rosen et al., 1964b; Cunningham and Goetzinger, 1974). Further, a personality behavior pattern (Type A personality) which is characteristic of a majority of heart disease patients has been investigated as one factor which may influence individual susceptability to the noxious effects of noise. The purpose of this study was to determine if two factors, cardiovascular endurance and Type A personality percentile ranking, have a relationship to the extra-high frequency thresholds of hearing. Industrial workers (ages 27-30, with normal hearing in the conventional frequency region) exposed to daily noise doses of 85-88 dBA served as subjects. An exercise test was used to determine car diovascular endurance. To determine the effect of the cardiovascular system on extra-high frequency hearing, two groups, varying in cardiovascular endurance, were tested for extra-high frequency sensitivity. The Jenkins Activity Survey was used to determine Type A personality percentile ranking. Type A personality percentile ranking, cardiovascular endurance and extra-high frequency thresholds were determined for 50 subjects. A two-factor ANOVA (Group x Frequency) revealed no significant differences in the extra-high frequency thresholds of two groups of industrial workers with varying cariovascular endurance. The effect of frequency was significant, while the group x frequency interaction was not significant. For 50 subjects, no significant correlations existed betweeen the thresholds of hearing at the extra-high frequencies and a) cardiovascular endurance and b) Type A personality percentile ranking. It was concluded that neither cardiovascular endurance nor Type A personality can be used to determine individual susceptability to the noxious effects of noise.