Transactions of the Korean Society of Mechanical Engineers A (대한기계학회논문집A)

The Korean Society of Mechanical Engineers (대한기계학회)
권호 표지
DOI QR코드

DOI QR Code

Detectability Evaluation for Alert Sound in an Electric Vehicle

전기자동차의 경고음에 대한 인지성 평가

  • Received : 2017.04.04
  • Accepted : 2017.07.05
  • Published : 2017.10.01
Download PDF
⟨ Previous Next ⟩

Abstract

Generally, the sound emitted from a vehicle powered by an electric motor is lower than that of internal combustion engine vehicles. Therefore, pedestrians often cannot detect approaching electric vehicles. Therefore, a certain additional warning sound is required for these types of automobiles. In this study, to develop an audible warning sound, nine warning sounds are designed based on signal processing and chord theory. The background noise measured on the road is also added to these synthetic sounds. The detectability of these warning sounds is evaluated by subjective tests. The sound metric is correlated to detectability and is investigated through psychoacoustic theory and subjective evaluation. It is determined that known psychoacoustic parameters such as loudness, sharpness, and roughness have a low correlation with detectability. However, it is found that the interval of harmonic sound correlates well with detectability.

모터로 구동되는 전기자동차에서 발생하는 소리의 특징은 일반적으로 내연기관 자동차보다 음압이 낮아, 보행자에게 접근하는 차량을 인지 못하는 경우가 종종 발생한다. 따라서 전기자동차에 추가적인 경고음이 필요하다. 잘 들리는 경고음을 개발하기 위해, 이번 연구에서는 화성학 이론과 신호처리를 기초로 제작하였다. 도로에서 측정된 배경소음은 합성된 신호에 추가되었다. 주관적 평가로 이 경고음의 인지성을 측정하였다. 심리음향 이론과 주관적 평가를 통해 인지성과 관련된 요소를 조사하였다. 라우드니스, 샤프니스, 러프니스 등 알려져 있는 심리음향 지표는 인지성과 낮은 상관성을 가졌지만, 반대로 음의 지속구간에 높은 상관성이 있음을 발견하였다.

Keywords

References

  1. Lee, S. K., Lee, S. M., Shin, T. and Han, M. U., 2017, "Objective Evaluation of the Sound Quality of the Warning Sound of Electric Vehicles with a Consideration of the Masking Effect: Annoyance and Detectability," International Journal of Automotive Technology, Vol. 18, No. 4, pp. 699-705 https://doi.org/10.1007/s12239-017-0069-6
  2. Zeitler, A., 2012, "Psychoacoustic Requirements for Warning Sounds of Quiet Cars," SAE Int. J. Passeng. Cars - Electron. Electr. Syst. Vol. 5, No. 2, pp. 572-578. https://doi.org/10.4271/2012-01-1522
  3. Hanna, R., 2009, Incidence of Pedestrian and Bicyclist Crashes by Hybrid Electric Passenger Vehicles, National Highway Traffic Safety Administration (NHTSA), DOT HS 811 204.
  4. Jacobsen, G. N., Ih, J. G., Song, W. K. and Macdonald, E. N., 2016, "Predicting Detectability and Annoyance of EV Warning Sounds Using Partial Loudness," Internoise2016, pp. 1706-1715.
  5. http://evader-project.eu, 2011, Electric Vehicle Alert for Detection and Emergency Response, eVADER project, FP7.
  6. Haas, E.C and Casali, J. G., 1993, "The Perceived Urgency and Detection Time of Multi-tone and Frequency-Modulated Warning Signals," Proceedings of the Human Factors and Ergonomics Society Annual Meeting, Vol. 37, No. 9, pp. 554-548.
  7. ISO 7029, 2000, Statistical distribution of hearing thresholds as a function of age.
  8. Otto, N., Amman, S., Eaton, C. and Lake, S., 1999, "Guidelines for Jury Evaluation of Automotive Sounds," SAE Technical Paper, doi:10.4271/1999-01-1822
  9. Parizet, P., Ellermeier, W. and Robart, R., 2014, "Auditory Warnings for Electric Vehicles: Detectability in Normal-vision and Visually-impaired Listeners," Applied Acoustics, Vol. 86, pp. 50-58. https://doi.org/10.1016/j.apacoust.2014.05.006
  10. Pinch, T. and Frank, T., 2004, Analog Days: The Invention and Impact of the Moog Synthesizer, Harvard University Press. ISBN 978-0-674-01617-0.
  11. Jones, D., 2012, Music Technology A Level, Darren Jones, Bournemouth, pp. 147-157.
  12. Lee, S. K., 2016, Objective Evaluation of Sound Quality in an Electric Vehicle Based on Effect of Temporal and Spectral Masking, FISITA 2016, F2016-ETNVH-3.
  13. Langford, S., 2013, Digital Audio Editing, Focal Press, Abingdon, pp. 44-57.
  14. Lee, S. M. and Lee, S. K., 2013, "Psychoacoustical Analysis and Application of Electroencephalo-graphy (EEG) to the Sound Quality Analysis for Acceleration Sound of a Passenger Car," Trans. Korean Soc. Noise Vibration. Eng., Vol. 23, No. 3, pp. 258-266. https://doi.org/10.5050/KSNVE.2013.23.3.258
  15. Zwicker, E. and Fastl, H., 1999, Psychoacoustics: Facts and Models, Springer, Berlin, pp. 203-233.
  16. Bismarck, V. G., 1974, "Sharpness as an Attribute of the Timbre of Steady Sounds," Acustica, Vol. 30, No. 3, pp. 159-172.
  17. Zwicker, E. and Fastl, H., 1999, Psychoacoustics: Facts and Models, Springer, Berlin, pp. 61-110.
  18. Ann, Y. C., Lee, J. H. and Kim, S. H., 2014, "Interior Noise Characteristics of the Electric Trains in Gyeongchun Line," Transactions of the Korean Society of Mechanical Engineers - A, Vol. 38. No. 7, pp. 817-822. https://doi.org/10.3795/KSME-A.2014.38.7.817