According to EU regulations - (EU) 2017/1576 , effective from July 1, 2019, all electric vehicles sold in the EU - including both all-new and existing models - must be equipped with an Acoustic Vehicle Alerting System (AVAS), also known as a low-speed warning sound system for electric vehicles, by 2021. Electric vehicles already on the road are required to be retrofitted with this system.

The system is designed to activate at speeds below 20 km/h and emit a sound to alert pedestrians and other road users of the vehicle’s presence, thereby helping prevent accidents involving electric vehicles. The regulation also specifies that the sound should be similar to that produced by internal combustion engine vehicle. 

COMMISSION DELEGATED REGULATION (EU) 2017/1576

Detailed link to the bill: https://eur-lex.europa.eu/eli/reg/2017/1576/oj