Do you react faster to sound than to light?

Yes. In simple reaction tests, responses to a sound are usually about 20–40 ms faster than responses to a visual cue, and some studies measure gaps of around 50 ms. The exact size depends on the people, the equipment and the stimuli.

Should I play League with sound on?

Yes, if your audio reaches you quickly. A sound that plays together with a visual cue gives you two signals instead of one, and in lab studies people respond faster to sight and sound together than to either alone. Sound also warns you about things you weren't looking at.

Do Bluetooth headphones add delay in games?

Usually, and often a lot. In RTINGS's latency tests, standard Bluetooth (SBC) averaged about 170 ms on gaming headsets and about 260 ms on other headphones and earbuds, while gaming headsets on their own wireless dongles measured 22–42 ms. Passive wired headphones add almost nothing.

Auditory vs Visual Reaction Time: Should You Play League With Sound On?

People react to a sound tens of milliseconds faster than to a visual cue. What the research says, why it happens, when headphone lag cancels it out, and how to use game audio.

Short answer: yes, play with sound on, as long as the sound reaches you on time. People react to sounds faster than to sights, and a sound that arrives together with a visual cue can make you faster still. A slow wireless connection can cancel all of that and more.

What the research says

Simple reaction time to a sound is reliably shorter than to a visual cue. A 2021 study of elite badminton players by Hülsdünker and colleagues sums up earlier work: auditory reactions are "well established to be around 20–40 ms faster" than visual ones. Individual studies land on either side of that:

Source	Setup	Sound	Visual	Gap
Hülsdünker et al., 2021	19 elite badminton players, button press	236.6 ms	287.7 ms	~51 ms
Typical values quoted by Jain et al., 2015	Simple reaction time	140–160 ms	180–200 ms	~40 ms

The absolute numbers vary a lot, because equipment, people and stimuli differ between studies. The direction doesn't. Jain and colleagues tested 120 medical students and found auditory reactions significantly faster than visual ones in both men and women. Expect a gap of roughly 20–50 ms, not one fixed number.

Two details from the badminton study matter for gaming:

The sound was deliberately delayed by 26 ms, the time a shuttle's sound takes to cross about 9 m of court. The players still reacted to it about 50 ms faster than to the visual cue.
With the visual cue and the sound together, they were fastest of all: 224.4 ms, quicker than sound alone. This is the redundant signals effect: two cues for the same event beat either one on its own.

Why sound is faster

Part of the head start comes from the sense organs. Hair cells in the inner ear are opened directly by mechanical force: Corey and Hudspeth (1979) measured a response delay of about 40 microseconds. Light first has to pass through a chemical cascade in the photoreceptors, and human cone responses to a dim flash peak after about 20 ms.

That isn't the whole story. A reaction gap of 20–50 ms also depends on how quickly the brain processes each signal, and the badminton study linked faster reactions to earlier auditory brain responses. Either way, hearing starts the race slightly ahead.

What that means in a game

In a fight, sights and sounds usually arrive together: a cast animation with its sound, an enemy Flash with its sound. You won't get the full 20–50 ms of a pure sound test, because you're watching as well as listening. What you get is the badminton result: two signals beat one.

That matters when the window is tight. On Medium in Flash the Engage, the charge lands about 260–330 ms after the enemy's Flash (the full millisecond budget). A few tens of milliseconds is a real share of that margin.

Sound also covers what your eyes miss. You can only focus on one part of the screen, but you hear sounds from all of it. An ability cast sound from a fight you weren't watching is a warning you'd otherwise get late or not at all.

When sound doesn't help

Wireless lag

Sound only helps if it reaches you before you'd have reacted to the picture. RTINGS measured headphone latency by recording two audio loops on a Windows PC, one through the headphones and one bypassing them, and taking the difference:

Connection	Measured latency
Passive wired headphones	about 1 ms or less
Gaming headset on its own wireless dongle	22–42 ms
Standard Bluetooth (SBC), gaming headsets	~170 ms average
Standard Bluetooth (SBC), earbuds and other headphones	~258–260 ms average

A 250 ms delay is several times the auditory head start. By the time an enemy Flash sound reaches your ears, you've already seen the Flash, or you've already been knocked up. Low-latency Bluetooth modes such as aptX Adaptive (Low Latency) do much better; RTINGS found them at roughly twice the latency of a dongle. RTINGS also notes that some headphones are faster when paired with a phone from the same brand, so results vary by setup. Just don't assume Bluetooth is fast enough.

Desk speakers are fine. Sound travels at about 343 m/s, so a metre of air adds about 3 ms.

Sounds you can't place

A sound tells you something happened, not always where. Headphones carry left-right position well, but front-back and up-down cues are much less reliable: in a study of 3D sound over headphones by Wenzel and colleagues, listeners made far more front-back and up-down confusions than with real sound sources, while left-right cues held up. Treat a sound as an alarm: it tells you to act, and your eyes tell you which way to Flash.

A crowded mix

Lab studies use one clean sound against silence. A big teamfight stacks dozens of sounds on top of each other. A cue you can't pick out of the noise gives you no head start.

How to use game audio

Use a fast connection. Wired headphones, speakers or a gaming headset's own dongle. Keep standard Bluetooth earbuds for music.
Make the important sounds audible. If your game has separate volume sliders, turn music down and sound effects up.
Learn the sounds of the threats you fear. An enemy Flash sound or the cast sound of an engage you face often is a tell, just like a wind-up animation. Learning tells is the trainable part of reaction time.
React to whichever comes first. Don't wait for the sound to confirm what you've already seen.

Try it · free, in your browserFlash the EngageA juggernaut charges in. Flash out of the zone before it lands.

Our benchmarks are silent

Our benchmarks don't play any sound, so they measure visual reaction on its own. That makes results comparable between players whatever their audio setup. With low-latency audio, your in-game reactions to cues that come with a sound may be a little faster than your benchmark result. For what counts as a good visual number, see What Is a Good Reaction Time for Gamers?