The hazards of listening to music while cycling could be reduced by a clever new invention that pipes the sound straight from your helmet into your head.
The gadget is fixed to the helmet strap and presses against the side of your face, transmitting musical vibrations through the bone to the inner ear, leaving your lugholes free to hear the sounds around you.
Bone conduction headphones have been around for more than a decade but most are stand-alone devices that have to be attached to the head with clips or straps.
The two inventors, university researchers who specialise in hearing technologies, realised that the webbing straps could provide the ideal location for the sound “transducer” so, for the first time, one has been integrated into a bicycle helmet.
In the prototype they’ve made and tested, they’ve shown that the helmet straps allowed the vibrating unit to be placed perfectly for the best transmission of sound to the cochlea – against the upper end of the jaw bone.
“The system can be glided along the front helmet webbing, which proves a simple way of adjusting its position against the skull “says Jérémie Voix, acoustic engineer and Associate Professor at the École de technologie supérieure (ÉTS) in Montréal, Canada.”
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“Another benefit of the proposed design is that it can be retrofitted on any existing helmet.” If Bluetooth is included, it means those annoying wires won’t be needed to connect the listening gizmo to the source of the music.
The researchers says that if the wireless music player is a smartphone then it could run a special app to tap into other sensors, such as the microphone or accelerometer, to automatically control the balance and volume of the music.
It could make the music quieter when it detects human speech, so the cyclist will be able to hear more clearly what’s being said. Likewise, I could pump up the volume when it detects noise from a rough road surface.
For pro teams it could make life easier for the team director to give his instructions to riders on the road. But, like the rest of us, they’ll have to wait until more studies have been done to find out how differently people hear bone-conducted sounds.
“Future research needs are to validate the proposed bike helmet prototype on a larger number of test-subjects, as inter-individual differences in perceived audio quality can be significant,” says Voix.
Design and validation of a bone conduction music playback for bike helmet by François Rochon and Jérémie Voix is published in Canadian Acoustics Vol 44, No. 1.
Max Glaskin is an award-winning freelance journalist who tweets about cycling and science as @CyclingScience1 and is the author of Cycling Science (published by Frances Lincoln UK, Chicago University Press USA, and seven other languages)