This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Acoustic Study on Motorcycle Helmets with Application of Novel Porous Material
Technical Paper
2019-32-0531
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
A critically high noise level inside protective helmet is a prevalent concern for motorcyclists. Especially at highway speeds where the noise level, regardless of helmet type can exceed 100 dB(A) and approaches threshold of discomfort, often resulting in temporary hearing loss. Despite of large share of persons exposed to such noise disturbance around the world, the in helmet noise levels have not significantly decreased over the last decades. Only few scientific publications can be found to systematically address this issue. Furthermore, in respect of driving safety even moderate noise levels are reported to impair reaction times and reduce attention of motorcyclists. At higher speeds the dominant helmet noise source is linked to aerodynamic turbulence around the helmet shell. The loudness and spectral contents mainly depend on the driving speed, windscreen configuration, riding position and helmet geometry. In this paper a series of on-road tests and laboratory experiments with three main types of helmets (“full face”, “flip up” and “open face” type) have been performed with the focus on in-helmet acoustics. Noise spectra at the location of rider's ears are measured, the results are analyzed and the noise source mechanisms are studied. A novel acoustic material, consisting of reticulated natural leather foam is presented for helmet noise control applications. It is demonstrated that a remarkable helmet noise level reduction can be achieved in a wide frequency range by the material into the critical interior regions of motorcycle helmets.
Recommended Content
Technical Paper | Numerical Methods for Combined Analysis of Seat and Ride-Comfort |
Technical Paper | Psychoacoustic Modelling of Sound Attributes |
Technical Paper | Threshold of Perception for Whole-Body Seated Vibration |
Authors
Citation
Lavrentjev, J. and Rämmal, H., "Acoustic Study on Motorcycle Helmets with Application of Novel Porous Material," SAE Technical Paper 2019-32-0531, 2020, https://doi.org/10.4271/2019-32-0531.Also In
References
- Van Moorhem , W.K. , Shepherd , K.P. , Magleby , T. D. , Torian , G. E. The effects of motorcycle helmets on hearing and the detection of warning signals Journal of Sound and Vibration 77 1 39 49 1981
- Aldman , B. , Gustafsson , H. , Nygren , Å. , Wersäll , J Hearing and motorcycle helmets Journal of Traffic Medicine 11 42 44 1983
- Chris Jordan , C. , Hetherington , O. , Woodside , A. , Harvey , H. Noise induced hearing loss in occupational motorcyclists Journal of Environmental Health Research 3 2 70 77 2004
- Lower , M.C. , Hurst , D.W. , Thomas , A. Noise levels and noise reduction under motor-cycle helmets 96 979 982 1996
- Mlynski , R. , Kozlowski , E. , Žera , J. Attenuation of noise by motorcycle safety helmets International Journal of Occupational Safety and Ergonomics 15 3 287 293 2009
- Holt , N. , et al Aeroacoustic sources of motorcycle helmet noise The Journal of the Acoustical Society of America 130 1164 2011 https://doi.org/10.1121/1.3621097
- Kennedy , J. , Carley , M. , Holt , M. , Walker , I. The effects of windscreen flow on noise in motorcycle helmets The Journal of the Acoustical Society of America 129 2652 2011 https://doi.org/10.1121/1.3588847
- Lavrentjev , J. ; Rämmal , H. On experimental techniques to determine acoustic performance of small exhaust silencers SAE Technical Paper Series 1 6 2009
- Kabral , R. , Rämmal , H. , and Lavrentjev , J. Acoustic Studies of Micro-Perforates for Small Engine Silencers SAE Technical Paper 2012-32-0107 2012
- http://www.eficuir.com/
- Kabral , R. , Rämmal , H. , Lavrentjev , J. , and Auriemma , F. Acoustic Studies on Small Engine Silencer Elements SAE Technical Paper 2011-32-0514 2011
- Aruniit , A. , Kers , J. , Goljandin , D. , Saarna , M. , Tall , K. , Majak , J. , Herranen , H Particulate Filled Composite Plastic Materials from Recycled Glass Fibre Reinforced Plastics Materials Science (Medžiagotyra) , 17 3 276 281 2011