Brains On! Science Podcast for Kids

Episode: "Why do electric cars sound so unique?"

Date: October 28, 2025
Host: Molly Bloom
Kid Co-host: Asher (Johnson Creek, Wisconsin)
Guest Expert: Jay Kapadia, Lead Engineer & Sound Design Specialist for General Motors

Episode Overview

In this lively episode, Molly Bloom and kid co-host Asher listen in on the world of electric vehicles (EVs), tackling the listener-submitted question: “Why are electric cars so quiet?” The episode investigates why electric cars sound different from traditional gasoline vehicles, how their signature sounds are designed, and why those sounds matter. With playful in-character cameos, a car-themed game show, and a special interview with a real-life EV sound designer, this episode is packed with engaging science, imagination, and kid-friendly fun.

Key Discussion Points and Insights

1. Why Are Electric Cars So Quiet?

• Internal Combustion Engines vs. Electric Motors

  • Gas-powered cars use internal combustion engines, which are “powered by explosions”—specifically, tiny blasts in cylinders, causing pistons to move and making a lot of noise.
    • “That explosion pushes down on something called the piston. The piston is inside of the cylinder and it's shaped like a thick hockey puck.” — Molly & Asher (06:34)
  • Electric cars use batteries and motors instead of explosions, which operate much more quietly.
    • “Instead of those noisy gas burning engines, electric cars use batteries to make our wheels spin.” — Electra Sparks (07:30)

• Why Noise Matters

  • The noise from traditional engines is a built-in safety feature; it lets pedestrians, cyclists, and visually impaired people know a vehicle is nearby.
  • Silent cars can actually increase danger, so in 2019, the US and Europe required EVs to have pedestrian alert sounds.
    • “Noise does help. People who are walking, visually impaired or on bikes, notice when a vehicle is nearby.” — Molly (08:16)
    • “In 2019, the US and Europe passed laws that require automakers to put speakers on the outside of all new electric and hybrid vehicles.” — Molly (08:49)

2. How Electric Car Sounds Are Designed

• Many EVs emit customizable sounds at low speeds—these are made to be noticeable, not scary or annoying, and suited to the car’s “personality.”
• The episode introduces Jay Kapadia, who describes the sound design process at General Motors.
  • “Designing EV sounds for me is like being a DJ, you know, a composer and a wizard all at once.” — Jay Kapadia (01:31, 16:00)

Jay Kapadia’s Interview Highlights

• Background
  • Jay studied music and sound design, and realized "cars were becoming more like computers on wheels."
    • “I’ve always loved sound...I realized cars were becoming more like computers on wheels. So I thought, wait, cars need a voice too.” — Jay (13:05)
• Types of Sounds Designed
  • Pedestrian alert sounds (outside car when moving slowly)
  • Internal sounds for user experience (starting car, shifting gears, button presses)
    • “With electric motors, that engine sound is really quiet...if you can't hear a sound that matches the speed you are moving, it will make you feel car sick because your senses aren't aligned.” — Jay (13:37)
• Design Considerations
  • The character or "voice" of the car: is it sporty, calm, or brave?
  • Design must follow safety rules (loud enough, not scary, weather-resistant) and match the brand.
    • "So there are also design rules that it should match the car's look and feel. A sporty car shouldn’t sound like a sleepy turtle." — Jay (15:05)
• Sound Creation Process
  • Uses synthesizers, computers, microphones, and even real world and traditional instruments.
    • “We used an instrument, ancient Australian instrument called the didgeridoo, which has some nice lower tones and frequencies, which kind of calms everyone down.” — Jay (16:00)
• Future of Car Sounds
  • Predicts increased creativity: cars may sound like waves, wind, or favorite video games in the future.
    • “We are inventing brand new sonic worlds...maybe your car could sound like waves, wind, or even your favorite video game sounds.” — Jay (17:10)

3. Why Do Electric Cars Sound So Unique?

• Each automaker can design distinct, memorable sounds that align with the car’s brand, character, and even mood—far beyond mimicking classic engine noises.
• Sounds are a blend of musicality, storytelling, and safety.

Notable Quotes and Memorable Moments

• On EV stealthiness:
  “So I've got a lot of shush in my woosh.” — Electra Sparks, electric car character (08:31)

• On making cars ‘sing’:
  “It's like giving the car its own soundtrack.” — Jay Kapadia (13:05)

• On dream sound design:
  “I'd love to make a car that sounds like a friendly robot dinosaur. Imagine a low rumble mixed with chirps and a soft roar...like a T. Rex with a big heart.” — Jay Kapadia (15:33)

• On future possibilities:
  “We are not just copying old engine-ish sounds, we are inventing brand new sonic worlds.” — Jay Kapadia (17:10)

Mystery Sound and Game Show Segments

Mystery Sound

[09:34, 25:49, 26:51]
The recurring “mystery sound” is played several times for listeners to guess.

• Asher guesses: sledding down a hill or rocks falling

• Molly jokes: “straw slurping up the remnants of a milkshake.”

• Answer revealed:[26:51]
  “That was the sound of a candle burning.” — submitted by Avery and Addison from Illinois

  • Discussion follows about wood wick candles and how surprising it is that candles can be loud!

Car-Themed Game Show

[20:14–23:46]
Molly runs a sound guessing game—Asher distinguishes car noises from ordinary household sounds (ceiling fan, hairdryer, pocket watch, turn signal, electric Corvette).

• “Do you have any thoughts about what the second one was?” — Molly (23:29)
• “No, I have no idea… it’s a pocket watch…” — Molly (23:31)
• “Oh, you’re a fancy person. I love that you had a pocket watch.” — Molly (23:39)

Key Timestamps

• 01:09 — Show introduction and episode setup
• 03:11 — Listener question: “Why are electric cars so quiet?”
• 05:14 — Fun explanation of combustion engines via Iggy the Delivery Van
• 07:19 — Electra Sparks (electric car character) explains how EVs work
• 08:49 — Laws requiring EVs to emit alert sounds
• 09:34 — First Mystery Sound
• 12:41 — Transition to sound design segment
• 12:47–17:31 — Jay Kapadia’s interview
• 20:14–23:46 — Car sound game show
• 25:49 — Mystery sound revealed: candle burning

Summary of Science Takeaways

• Gas engines make noise because they use mini-explosions to move pistons and wheels, which helps keep roads safer for everyone.
• Electric cars use quiet batteries and motors, making road safety a new challenge.
• To solve this, car designers create unique, brand-specific sounds for EVs, merging technology, safety, and creativity.
• The future of car sounds is only growing more imaginative—with possibilities ranging from musical motifs to video game-inspired noises.

Episode Tone and Style

True to Brains On! form, the episode is energetic, humorous, and interactive. The hosts, kid co-host, and even characters like Iggy the Delivery Van and Electra Sparks add whimsy and make technical details accessible to curious young listeners. The expert interview is playful and inspiring, blending a love of science and sound with creativity.

For Curious Listeners

• To learn more about electric car history, check out the Forever Ago podcast episode recommended ([09:06]).
• To participate in the show or send your own sound ideas, visit brainson.org.

Memorable Closing:

“I picked my sounds myself. Aren’t they amazing?” — Electra Sparks (24:10)
“I’m pretty sure you’ll never sneak up on anyone ever again.” — Molly Bloom (24:14)

Perfect listening for kids, parents, and anyone fascinated by the blend of science, sound, and imagination that keeps our world—and our cars—moving!