Children who say hand dryers 'hurt my ears' are correct: A real-world study examining the loudness of automated hand dryers in public places.

INTRODUCTION: Previous research has suggested that hand dryers may operate at dangerously loud levels for adults. No research has explored whether they operate at a safe level for children's hearing. Children's ears are more sensitive to damage from loud sounds than adult ears. Health Canada prohibits the sale of toys with peak loudness greater than 100 dB. This study tested installed dryers in public washrooms to see if they were safe for children's hearing.

METHODS: Forty-four hand dryers in public washrooms were each measured for peak sound levels in a standardized fashion, including at children's ear canal heights. Each dryer was measured at 10 different combinations of heights and distances from the wall, and with and without hands in the air stream coming from the hand dryer, for a total of 20 measurements per dryer.

RESULTS: Xlerator units performed the loudest, with all being louder than 100 dBA at all measurements whenever hands were in the airstream. Several Dyson Airblade models were also very loud, including the single loudest measurement of 121 dBA. While some other units operated at low sound levels, many units were louder at children's ear heights than at adult ear heights.

DISCUSSION: Many dryers operated much louder than their manufacturers claimed, usually greater than 100 dBA (the maximum allowable noise level for products/toys meant for children).

CONCLUSION: This study suggests that many hand dryers operate at levels far louder than their manufacturers claim and at levels that are clearly dangerous to children's hearing.