BMW i3 e-car electric engine

BMW i3: starting the engine and idle running

Increasing air pollution, rising noise levels and ever growing numbers of cars on the roads leading to more and more traffic jams have provoked criticism of our transport systems and technologies as well as criticism of our use of finite energy sources such as oil. Especially our reliance on the traditional combustion engine has been challenged. One alternative to the combustion engine in cars is the electric motor. Currently it is unclear whether the eCar can gain acceptance. However, if it does it will change the noise of traffic as we know it.

The electric motor itself makes hardly any noise. Especially when the eCar is slow and the wheels or the wind do not produce any additional sound, this silence may be dangerous for pedestrians, cyclists and other cars. They would not be able to hear the oncoming vehicle and could walk/cycle/drive right in front of it. Therefore some companies have introduced exterior sound systems that are supposed to warn other traffic participants. An EU-law, which has been issued in 2014, states that from 2019 onwards all new models of electric vehicles have to issue some sort of noise. These sounds are designed by sound designers. The sounds do not simply mimic the sound of combustion engines but have their own means to signal acceleration and slowing down.

The BMW i3 is one of the electric cars produced by the Bavarian company BMW. In this recording you can hear the starting of the engine and the idle state of the car with the “eDrive exterior sound” switched off. When the engine starts you can hear the ventilator that cools down or warms up the battery of the car to improve its performance depending on the outside temperatures. A thermostat controls the ventilator to keep the battery at an ideal temperature.

The recordist stood next to the left front wheel. The battery is underneath the passenger seats and the motor is positioned at the rear of the car.

Photographer: Kathinka Engels
Sound Recordist: Kathinka Engels


8.9 MB
15 s
2 (Stereo)
Sample rate:
Bit rate:
Bit depth:
96 kHz
4608 kb/s
32 bit

Recorded on April 5, 2018, car sharing company
Dortmund, GERMANY
Creative Commons License