Why modern engines got so quiet and now need synthetic sound

Modern engines are quieter than ever due to electric design and insulation. But artificial sound is being added back in—here’s why and what it means.

It’s an odd sensation: watching a sleek electric vehicle glide by in near-total silence. No rumble, no growl — just the faint whisper of rubber on asphalt. Welcome to the future of mobility, where quietness is king. But as the volume drops, new questions rise. Why are today’s engines so quiet — and why are automakers now bringing back sound on purpose?

Electric by nature, quiet by design

The core reason lies in the mechanics. Electric motors don’t combust fuel. They don’t have pistons, valves, or exhaust systems. Fewer moving parts means fewer vibrations — and far less noise. What you hear, mostly, is nothing at all.

Acoustic isolation on a new level

Yet it’s not just about the powertrain. Modern vehicles are built with aerodynamics in mind, reducing wind resistance and cutting ambient noise. Interiors are packed with sound-absorbing materials like expanded polypropylene foam, muting tire and suspension noise as well. The result? A surprisingly cocooned driving experience.

When silence turns into a risk

But too much quiet isn’t always a good thing. Studies show that EVs and hybrids are twice as likely to hit pedestrians, especially in urban environments. People simply don’t hear them coming — a serious issue for the visually impaired.

In response, the European Union now mandates that all new electric vehicles include Acoustic Vehicle Alerting Systems (AVAS), which emit sound when driving below 20 km/h.

Soundless driving, sensory disconnect

Drivers, too, have mixed feelings about the hush. Without engine noise, gauging speed or throttle response becomes harder. The ride might be smoother — but for some, it also feels disconnected. The familiar acoustic cues are gone, and that can reduce both safety and driving pleasure.

Enter: artificial sound

That’s where sound engineering steps in. Automakers are deploying Active Sound Design — systems that create artificial soundscapes inside and outside the car. Not just random noise, but curated audio identities tuned to reflect power, motion, or even brand personality.

Vehicles like the BMW M5 and Ford Mustang Mach-E already use synthesized sound to bring back that visceral connection between car and driver — even when there’s no engine roar to begin with.

The future: sounds like you

Looking ahead, personalization could be the next frontier. Imagine choosing your EV’s voice — from a retro V8 rumble to a sci-fi hum. As cars grow quieter, synthetic sound may be more than a necessity. It may become part of how a vehicle expresses itself — and how we, in turn, relate to it.