Electric and hybrid cars will have to generate noise to make them safer for pedestrians, especially the visually impaired, the European Parliament says.
MEPs agreed that in future the vehicles must be fitted with devices to make them "sound similar" to cars with combustion engines.
The move has been welcomed by campaigners.
MEPs also voted to tighten noise emission standards for cars, vans, lorries and buses over the next decade.
The new law is expected to be rubber-stamped by the European Council.
Under the revised rules, new models of electric and hybrid vehicles will have to make a noise by 2019 and all new electric and hybrid cars must be audible by 2021.
The BBC's Ben Wright in Brussels says the move has been welcomed by UK charity Guide Dogs for the Blind - which campaigned for the change.
However, with the number of quiet cars increasing all the time, it said the 2021 deadline was too late.