Abstract
Measurements of the at-ear helmet-generated aerodynamic noise and helmet insertion loss were carried out for the two major types of motorcycle helmets. From these data and existing information on noise generation by flow around a bare head it was found that for quiet motorcycles at typical operating speeds a significant part of the rider at-ear noise is generated by the air flow. An assessment of the possibility of hearing damage was then carried out. Only extreme high speed gives a risk of hearing damage.