Icon of program: Speed of Sound

Speed of Sound for Android

By OctetFreeUser Rating

Key Details of Speed of Sound

  • Warning: This is heavy on the battery. Please use a car charger.
  • Last updated on October 16, 2020
  • There have been 6 updates
  • Virus scan status:

    Clean (it's extremely likely that this software program is clean)

Enlarged image for Speed of Sound

Developer's Description

Warning: This is heavy on the battery. Please use a car charger.

Warning: This is heavy on the battery! Please use a car charger.

If you're having trouble with the app not running when your screen is off, please see here: https://dontkillmyapp.com/

Speed of Sound automatically adjusts your music player's volume while you're driving about with your GPS, lowering the volume while driving slowly or at a stoplight, and cranking it up on the highway. This is a feature available in some more expensive cars and sound systems. We're giving it to you for free to use on your phone. Just start up your music player, plug your phone into your car stereo, and open Speed of Sound.

When you're done with your drive, you can take a look at a map of what songs you listened to and where. Don't worry about tagging that one song-you-can't-remember-the-name-of, just check the map afterwards.


Customizable volume levels and speeds

Map of songs you listened to on your drive, compatible with Google Music, HTC/Samsung music players, WinAmp, and any player that supports Last.fm scrobbling

Smooth volume adjustment

Smart speed filter that avoids random GPS jumps

Options to auto-activate when plugged into headphones, charger, selected Bluetooth devices, and when the app starts

Tasker integration as an action


While this app is great to use while driving, it's designed to keep your eyes on the road and not your phone/radio. So don't mess with this app or your phone at all while driving.


We'd love to hear your feedback. Submit an issue on GitHub, or send us an email with your thoughts.

Help Translate

Want to translate Speed of Sound into another language? Check us out on Transifex:



Can I use this with my car radio?

That's what it's for -- as long as you have an aux input and a decent cable to plug into your phone and radio, you're all set. If you don't have that, this won't be of much use unless you want to listen to music on your phone's awful speaker.

What are some recommended settings?

The defaults that come with the application have been tested in the wild and have shown to work well. That said, everyone's tastes are different. We recommend choosing a slow and fast speed that aren't too far apart, because the effect is greater than you might think. Also, many phones get really quiet below a volume of 60, so pick volumes that are not too far apart.

This drains my battery!

Yes, yes it does. Plug your phone into a charger while you drive.

Why does my phone seem to "jump" between volume levels?

Unfortunately, this behavior shows up on many phones. We do our best to make volume changes smooth, but a lot of phones will only change the volume in increments of 5% or so. Not a whole lot we can do here, sorry.

Where's the source?

The code is available under the GPLv2 on GitHub: https://github.com/jpeddicord/speedofsound

Feel free to fork, file bugs, or stare in awe.


Position & GPS - We sorta need this to know how fast you're going.

Bluetooth - Used to auto-activate when you connect to a Bluetooth music player.

Internet, Accounts, Network, External storage - All for Google Maps alone.

Feature banner photo CC-BY davebloggs007: https://flic.kr/p/fdhBPP

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