Cardiovascular effects of impulse noise, road traffic noise, and intermittent pink noise at LAeq = 75 dB, as a function of sex, age, and level of anxiety: a comparative study

Summary

In a previous paper, in which the experimental conditions of the present research are fully described (Parrot et al., this issue), heart rate (HR) was studied in 60 male and in 60 female subjects in response to a pile-driver noise (P), a gunfire noise (G), a road traffic noise (T), and an intermittend pink noise (R), all noises being emitted at the same LAeq = 75 dB for 15 min. Digital pulse level (PL) responses were concomitantly surveyed by the use of pulse oxymetry, allowing continuous arterial oxygen saturation (SaO₂) readings. An index of pulse reactivity (PRI) could be calculated. Arterial blood pressure was measured 7 times from the beginning to the end of each trial. At rest, within the last minutes preceding each exposure to any of the 4 noises, no difference for conditions or for age in prestimulus PL was observed. In all cases, sex is a highly significant source of variation: Mean resting SaO₂ values are higher in women than in men. Mean SaO₂ at rest was also found to be significantly higher in anxious (Am) than in anxiety-free (Nm) men. When the noise was on for 15 min, ancrease in PL prevailed to be in most cases in men. In contrast, decrease or near-zero changes prevailed in 1 case out of 2 in the female subgroups. In all groups, the mean PRIs are significantly higher in men. In no case did the age factor prove to be a significant source of PRI variation. In AM and NM, amplitudes of PRI proved to be significantly different for the different noises: They are higher during exposure to T than during exposure to P, G and R ranking in third and fourth position, respectively. The same ranking of noises as regards pulse response induced is also met in women of the same age range. In YM and OM, too, T ranks first and before P for inducing the most important PR. In no case did anxiety prove to be a significant source of variation as regards the vasomotor responses. In all the cases, systolic and diastolic blood pressure (SBP, DBP) levels at rest were found to be significantly higher in men than in women. Under noise exposure a systematic decrease of SBP and DBP was observed as an overall tendency, but this change never achieved statistical significance and was without any significant after-effect. No significant role of anxiety was observed, but incidentally age was found to be a significant factor in DBP changes.