The influence of helmets on sound localisation in motorcyclists

Abstract

Motorcyclists are among the most vulnerable road users globally, they enjoy less protection than car drivers and experience higher speed collisions than cyclists, with less mobility and spatial awareness to avoid crashes. Sound localisation (SL) while wearing military and ski helmets has been a significant area of research to improve spatial awareness, but no research has been completed thus far on the impact of motorcycle helmets on SL. This project aims to examine experimentally the impact of a motorcycle helmet on the Head Related Impulse Response (HRIR), and therefore determine the extent of the impact on SL ability of a user. A database of HRIRs as a function of position in the horizontal place was established with and without a motorcycle helmet. The variation in the signals was evaluated, and it was found that the helmet results in significant loss of higher frequencies, important for resolving front-back confusions. It is also demonstrated that the overall sound attenuation would result in reduced SL ability of the rider. A novel system to compensate for the changes in the HRIR was developed and experimentally tested to mitigate the impact on SL ability for the wearer.