There are few sounds in nature that interfere with our ability to communicate vocally and almost none that in any way pose a threat to the hearing apparatus. It is interesting to consider, for instance, that while the naked voice can be raised to quite a loud level (say about 80 decibels at a distance of a few feet), it cannot be raised in-normal human intercourse to a point where it might endanger the ear (over 90 decibels).

Schafer, Murray R, The Soundscape- Our Sonic E…, loc. 676