Experimental Evaluation on Noise Reduction Performance of a Motorcycle Helmet

Öz

Anahtar Kelimeler

• Kask,Ses azalımı,Deneysel Akustik

Experimental evaluation on noise reduction performance of a motorcycle helmet

Öz

Motorcycle helmets are generally thought to be only protection of motorcycle drivers against head injuries as well as loud noise in traffic. While there have been several papers on noise elimination capabilities of motorcycle helmets, no controlled study has been reported to compare different types of test conditions in literature. The purpose of this study is to assess noise reduction capacities of a motorcycle helmet under different types of acoustical loadings as well as environments and to identify better test condition. Firstly, a Head & Torso simulator with and without the motorcycle helmet in a built acoustical cabinet was exposed to digitally generated sound to investigate insertion loss values. Besides, the Head & Torso simulator was fixed onto a motorcycle to simulate actual driving conditions. Sound pressure levels were captured at the ear level to obtain insertion loss values in case of motorcycle noise for different engine speeds. By comparing calculated insertion losses, it was revealed that considerable differences existed between tests for different conditions. Beneficial interpretations were deduced and thus, a practical solution was presented for accurate measurements acoustic performance of the motorcycle helmets in laboratory conditions.

Anahtar Kelimeler

• Insertion loss,Motorcycle helmet,Helmet acoustic,Noise reduction,Experimental acoustic

Kaynakça

1. [1] B. C. Ross, “NOISE EXPOSURE OF MOTORCYCLISTS,” Annu. Occup. Hyg., vol. 33, no. l, pp. 123–127, 1989.
2. [2] Maue J.H., “Noise exposure of motorcyclists,” Audiol. Pract., vol. 7, no. 4, pp. 6–7, 1991.
3. [3] A. W. McCombe, “Hearing loss in motorcyclists: occupational and medicolegal aspects.,” J. R. Soc. Med., vol. 96, no. 1, pp. 7–9, 2003.
4. [4] J. L. Fletcher and C. W. Gross, “Effects on hearing of sports-related noise or trauma,” Sound and Vibration, vol. 11, no. 1. pp. 26–27, 1977.
5. [5] W. K. Van Moorhem, K. P. Shepherd, T. D. Magleby, and G. E. Torian, “The effects of motorcycle helmets on hearing and the detection of warning signals,” J. Sound Vib., vol. 77, no. 1, pp. 39–49, 1981.
6. [6] A. M. Jongepier and A. van der Weerd, “A. M. Jongepier and A. van der Weerd, " Practical research into application possibilities of otoplastics with motorcycle patrols of the state police, " Technical Report No. AG 90/1863, RBB, Hague, Netherlands (1990), translated from Dutch.,” 1990.
7. [7] A. W. McCOMBE, J. BINNINGTON, and T. S. McCOMBE, “Hearing protection for motorcyclists,” Clin. Otolaryngol. Allied Sci., vol. 18, no. 6, pp. 465–469, 1993.
8. [8] J. Kennedy, N. Holt, M. Carley, and I. Walker, “The influence of the acoustic properties of motorcycle helmets on temporary hearing loss in motorcyclists,” Acta Acust. united with Acust., vol. 100, no. 6, pp. 1129–1138, 2014.

9. [9] M. C. Lower, D. W. Hurst, and A. Thomas, “Noise levels and noise reduction under motorcycle helmets,” Proc. Internoise 96, no. 1, pp. 979–982, 1996.
10. [10] A. Lower, M.C., Hurst, D.W., Thomas, “Noise Levels and Noise Reduction under Motorcycle Helmets,” in Proceedings of Internoise 96, 1989, vol. 2, no. 1, p. 1989.
11. [11] R. Młyński, E. Kozłowski, and J. Żera, “Attenuation of noise by motorcycle safety helmets,” Int. J. Occup. Saf. Ergon., vol. 15, no. 3, pp. 287–293, 2009.
12. [12] J. Kennedy, N. Holt, M. Carley, I. Walker, M. Engineering, and C. Down, “Spectral filtering characteristics of a motorcycle helmet,” in Proceedings of Meetings on Acoustics, 2011, vol. 12.
13. [13] J. A. D. Carrilho and M. C. Gameiro da Silva, “Aerodynamic noise in motorcycle helmets,” in II LAETA Young Researchers Meeting FEUP, 2012.
14. [14] A. W. Mccombe, J. Binnington, and D. Nash, “Two solutions to the problem of noise exposure for motorcyclists,” Occup. Med. (Chic. Ill)., vol. 44, no. 5, pp. 239–242, 1994.
15. [15] C. H. Brown and M. S. Gordon, “Motorcycle Helmet Noise and Active Noise Reduction,” Open Acoust. J., vol. 4, no. February, pp. 14–24, 2011.
16. [16] L. Liu, S. M. Kuo, and K. P. Raghuathan, “Active Noise Control for Motorcycle Helmet,” Int. J. Inf. Commun. Eng., vol. 6, no. 2, pp. 102–107, 2010.
17. [17] C. H. Bies, D.A. and Hansen, Engineering noise control: theory and practice, 2nd ed. London: E. & F.N. Spon., 1996.