Why do electric cars make a sound at low speed?

EU law requires an acoustic alerting system, AVAS, from start up to about 20 km/h and when reversing, so that pedestrians notice the car.

Explained in

eMobility and EV basics · Stop 03How does an electric motor drive the wheels?Battery, inverter, motor, one fixed gear: the short path from stored energy to turning wheels, and why electric cars have to make a sound at low speed.

Because an electric drive is so quiet at low speed, the EU requires an acoustic vehicle alerting system, AVAS. It must generate a sound from start up to about 20 km/h and when reversing, so that pedestrians, especially blind and visually impaired people, notice the car. AVAS has been mandatory for all new hybrid and electric cars since 1 July 2021.

From “A sound by law”, stop 03

Terms

  1. AVASAcoustic vehicle alerting system: the sound EU law requires from electric and hybrid cars up to about 20 km/h and when reversing.
  1. What is the difference between a hybrid and a plug-in hybrid?A hybrid takes all its energy from fuel; its small battery is filled by the engine and by braking. A plug-in hybrid also charges from the grid, so everyday distances can run on electricity.
  2. What is the difference between LFP and NMC batteries?NMC stores more energy per kilogram. LFP contains no cobalt and costs less: in 2025, LFP packs were on average more than 40% cheaper per kWh.
  3. What is the difference between kW and kWh?kWh is an amount of energy, for example what the battery holds. kW is a rate, how fast energy flows; time equals energy divided by power.
  4. Why does range drop on the motorway?Air drag grows with the square of speed, and the power needed with its cube. Above about 100 km/h, it dominates consumption.
  1. EUR-Lex: Regulation (EU) No 540/2014 on the sound level of motor vehicles, Article 8 and Annex VIII (AVAS). https://eur-lex.europa.eu/eli/reg/2014/540/oj. Checked 09 Oct 2026. © European Union, reused under Commission Decision 2011/833/EU.