The vehicles that are propelled by electric motors are becoming popular, and the number of production is rapidly increasing recently. While the electric and hybrid electric vehicles (EV, HEV) has major population in such vehicle, fuel cell vehicles (FCV) are also introduced in the family. The propulsion noise of such vehicles are lower than conventional internal combustion engine vehicles (ICEV), particularly at low speeds. It is a keen interest to examine the noise reduction effect of such vehicles. In order to introduce EVs into the noise prediction models, such as ASJ RTN-Model or CNOSSOS-EU, it is necessary to know the sound power level emitted by an electric vehicle and to develop a model of sound power level depending on the vehicle speed. In this research, several measurements on sound power level were carried out on a dense asphalt pavement. The result showed that the sound power level of test EVs in 20 to 30 km/h speed range were 2 to 4 dB lower than the ICEV. Additionally, the comparison of the frequency analysis was conducted to evaluate the effect of Acoustic Vehicle Alerting System (AVAS) to improve the auditory detectability by pedestrians.