How the sound test works
The test opens with the signal set to Sound. Click the box, tap it or press Space, and it tells you to listen. After a random wait of 1.5 to 5 seconds you hear a short beep: press the moment you hear it. The box stays exactly as it is, so your eyes can’t help. After five attempts you get your average, best, median and consistency, and pressing before the beep only repeats that attempt.
Then switch the signal to Colour and do a round the same way, clicking when the box turns green. The result line compares the two rounds: how many milliseconds faster you were to the sound or to the colour, with both averages.
Sound or light: which is faster?
Reaction time to a sound is usually shorter than to a light. The figures usually quoted for college-age adults, from A. T. Welford’s Reaction Times (1980), are about 190 ms to a light and about 160 ms to a sound, measured with laboratory equipment. A 2015 study by Jain and colleagues in the International Journal of Applied and Basic Medical Research ran almost the same test as this page: 120 medical students aged 18 to 20 pressed the space bar on a laptop when they heard a beep or saw a red circle. Reactions to the beep were significantly faster, in men and women alike.
Reactions to a sound can be very quick indeed. Measuring athletes in starting blocks fitted with force sensors, Pain and Hibbs (2007) found that a fifth of the sprint starts in two of their test conditions came less than 100 ms after the start signal. The sprint start test puts you in the blocks.
Making the comparison fair
- Use the same device, hand and key for both rounds.
- Mind the audio delay. Sound needs time to leave your computer or phone. After the first beep, the line under the box shows how much output delay your browser reports; that part is taken out of your times. Bluetooth headphones add delay the browser often can’t see, so use wired headphones or the device’s own speakers.
- Alternate. The first round of the day is often the slowest, so try sound, colour, then sound again.
- Keep the volume comfortable, not loud, and find a quiet spot so you don’t miss the beep.
Reading the result
A browser test measures more than your nervous system: the screen, the mouse or touchscreen and the audio output all add their own delay, so expect higher numbers than the laboratory figures above. What this page is good at is the difference between your two rounds on the same device. If sound comes out slower than colour, check the audio delay first. One caveat: the audio delay your browser reports is taken out of the sound round, but your screen’s own delay, which browsers can’t measure, stays in the colour round, so a few milliseconds of a lead for sound can come from your screen (more on a TV).
Your best average to a sound is kept on this device next to your other records. For the standard test, go back to the classic reaction time test; for a visual start with a twist, try the F1 start lights. To check your speakers or headphones themselves, use the speaker test.