02 / 08
Visual vs. Auditory Reaction Time — Why We React Faster to Sound
Why studies find auditory reactions faster than visual ones, and the device factors that can reverse that difference in a web test.
Even when the same person presses the same button, reaction time differs depending on whether the signal is light or sound. Many studies find that auditory reaction time is shorter than visual reaction time.
Research findings
Jain et al. (2015) measured the visual and auditory reaction times of 120 medical students aged 18–20 and reported that auditory reactions were significantly faster than visual ones in both men and women. In the same study, male students were slightly faster than female students for both stimuli.
Why is sound faster?
- Conversion — The retina converts light into an electrical signal through photochemical reactions, while the hair cells of the ear convert vibration mechanically and directly into an electrical signal.
- Pathway — The path an auditory signal takes to reach the cerebrum is shorter than the visual one.
- Attention — Sound is detected no matter which direction it comes from, whereas a visual signal must be where your gaze is directed to be seen well.
In web tests, it can be reversed
When measured in a browser, auditory reactions often come out slower. That's because audio output latency is larger than the human difference.
- The operating system and audio driver collect sound into small chunks (buffers) before output, which takes a few to tens of ms.
- Bluetooth earbuds and speakers can be much slower than that due to wireless transmission and codec processing.
- This site uses Web Audio's
getOutputTimestamp()to account for the output time reported by the browser, but it cannot know the latency inside a Bluetooth device.
How to compare accurately
- Use wired earphones or your device's built-in speaker.
- Measure visual and auditory modes back to back on the same device.
- Measure several sets in each mode and compare the medians.