Globally, there are concerned to reduce greenhouse gas – GHG emissions. Under this scenario, a wide range of policies and technologies are being imposed, targeted into strengthening environment protection, pollutant emission reduction and efficiency improvement. To address this issue, electric vehicles (EV) have taken greater importance. Numerous countries have started incentivizing the sale of electric vehicles to push greater adoption owing to zero vehicle emission. Electric vehicles are considerably quieter than engine-powered vehicle. However, there are many factors contribute to automotive noise, whether the vehicle is electric or has an internal combustion engine. Human ear respond differently to different frequencies of sound and this response varies with age, sound level and the frequency content. This study explores the sound characters of electric and internal combustion engine vehicles (buses) in terms of sound quality (SQ). Interior noise measurements conducted on the EV and ICE buses at different vehicle operating conditions. It has been insured that the overall technical specification of selected test vehicles are similar, except the powertrain, wherein one will be internal combustion engine and other will be electric motor driven. Jury tests conducted for subjective assessment and sound quality parameters such as articulation index, sharpness, loudness, fluctuation strength, prominence ratio, tonality, etc. were evaluated to compare the objective performance of the vehicles. In general, the overall interior noise levels of EVs are less than ICE. However, subjectively high-frequency noise components observed in EV, which are perceived as irritating and unpleasant. There is very little broadband noise in EV, but mostly pure tone. Especially, as it moves to higher speed, the pure tone noise goes on increasing. The significant higher levels observed for various sound quality parameters in EV compared to ICE vehicle. In conclusion, the traditional approach to assess the overall interior noise level of electric vehicles will not be effective. It is vital to evaluate for various sound quality parameters, which affects human perception.
Mr. Pradeep Jawale, DGM, ARAI