MAN Truck & Bus


AVAS: E-bus sound to improve safety 


Electric buses are quiet. It’s great, but it’s also potentially dangerous because other road users can barely hear the vehicle coming. That’s why the industry has been working on a uniform acoustic warning system.

While great emphasis was placed on suppressing the noise generated by internal combustion engines in the past, sound designers today are working on making the quiet electric vehicles on our roads louder. This is because an approaching internal combustion vehicle can be noticed at an average distance of 36 metres, while an electric vehicle travelling at the same speed is not noticed until it is just 13 metres away. 

AVAS as an early warning system 

Since summer 2021, the EU requirement that new electric cars must be equipped with an acoustic vehicle alerting system (AVAS) has been in effect. The EU prescribes a driving noise at low speeds. The AVAS must automatically generate a continuous noise in the range from 0 to 20 kilometres per hour. The noise produced by the tyres is sufficient at higher speeds. The leeway is limited for the AVAS sound, as it must be comparable to the sound of an internal combustion engine-powered vehicle from the same class. Ideas such as space-age Star Wars sounds or synthetic birdsong are therefore not allowed. 

The Verband Deutscher Verkehrsunternehmen (VDV – Association of German Transport Companies) is working with the sector and industry to find new ways to develop a standardised sound for e-buses. Rudi Kuchta, Head of Business Unit Bus at MAN Truck & Bus and Chair of the VDV Industry Forum, said: “It’s always good when qualified and coordinated standards are developed from within an industry. It’s good for customers – including when it comes to costs. At the same time, it gives manufacturers enough freedom to develop this standard further.” 

0 Decibels

is the maximum volume of the artificial E-bus noise on the MAN Lion's City E.


0 kilometres per hour

is the speed at which the AVAS sound of the MAN Lion's City E is completely switched off. 


An e-bus sound “Made in Germany” 

The aim is to establish a characteristic “Made in Germany” e-bus sound. To make it possible to set this acoustic industry standard, the VDV is working with interest groups, including associations for the visually impaired. On 13 July, the winner of a student competition involving the FOAM Institute Berlin was announced at ElekBu, the VDV electric bus conference and trade fair: Lukas Esser from the Berlin University of the Arts. He called his sound the “Friendly Neighbour”, and it is now set to be developed into an industry standard. 

The e-bus sound is an important aspect of e-mobility for MAN. “Here at MAN, we support the VDV initiative for a standardised and modern e-bus sound. The future of urban transport is electric, so public transport must also remain safe and attractive,” stressed Rudi Kuchta at the award ceremony, adding, “Our Lion’s City E is already on the roads of many of Europe’s cities and is loved equally by drivers, passengers and operators. However, we want many more electric buses on our streets: by 2025, half of our new city buses will use alternative means of propulsion, and we’re assuming that only five years later, in 2030, 90 per cent of our city buses will be supplied with battery power.” 

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Rudi Kuchta wants a uniform sound for e-buses.

We at MAN support the VDV initiative for a uniform and modern e-bus sound. Because the future of urban mobility is electric, and public transport must also remain safe and attractive.

Rudi Kuchta
Head of Business Unit Bus
MAN Truck & Bus 

MAN AVAS system

The speaker for the AVAS is beneath the right headlamp on the MAN Lion’s City E. A reversing beeper provides additional safety at the rear. The sounds are activated on starting (stationary sound) and on reversing. The artificial driving noise gets louder with increasing speed and becomes quieter again as the vehicle slows. The volume is between 56 and 75 decibels.  

On acceleration, the sound alters from low to high frequency. It is important that the sound of the tones is less than 1600 hertz to ensure that people who do not hear well are made aware in good time. The MAN Lion’s City E exceeds the legal requirements (sound up to 20 kilometres per hour): above 20 kilometres per hour, the AVAS slowly fades out and does not switch off completely until 40 kilometres per hour is reached.  

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Signal transmitter: The loudspeaker for the Lion's City E's AVAS system is located under the right headlight.

Text   Anke Kotte

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