Controlled signal
The tool generates the test inside your browser with a bounded app-level gain. Your operating-system and hardware volume remain separate.
Left Right Audio Test
Select a channel, press play and confirm where the tone appears. Spoken instructions are centered; the following tone is the directional signal being tested.
Confirm selected signal
The spoken instruction is centered. The tone that follows is the directional test signal. Only your confirmation determines the result.
Local by default
Output tests do not upload audio. Microphone tools request permission only when started and explicitly state what stays in memory.
SCOPE / 01
What this test checks
The browser creates separate left, right and stereo signals. Comparing the intended digital channel with the side you physically hear is a direct way to find reversed routing, mono summing or a missing output channel.
- Connecting headphones, speakers, an audio interface or an analog adapter for the first time.
- Game, movie or meeting audio appears on the wrong side or one channel is missing.
- Whether the left and right digital channels reach their matching physical sides.
- Whether a stereo signal appears centered instead of being pulled strongly to one side.
- Whether a supposedly directional signal is being combined into mono.
- Which cable or component failed without a second connection test.
- Equal acoustic loudness between unmatched phone or laptop speakers.
PROCEDURE / 02
How to run this test
Keep the level moderate and change one thing at a time so the result remains useful.
- 01
Wear headphones correctly or face your speakers.
- 02
Play Left and confirm the tone comes only from the left.
- 03
Repeat for Right, then play Stereo for a centered image.
- 04
If a channel is missing or reversed, open the guided diagnosis.
INTERPRETATION / 03
What your result means
Match what you heard or saw, change one variable, then use the linked check to verify the result.
| Observation | Likely cause | Next step | Retest |
|---|---|---|---|
| 01Left plays on the right and right plays on the left. | The headphones may be worn backward, speaker positions or analog cables may be swapped, or interface routing may be reversed. | Correct one physical or software mapping at a time and rerun both directional signals. | Check stereo routing |
| 02Both directional signals play from both sides or the center. | Mono accessibility mode, a mono speaker or a channel-combining adapter is likely summing the stereo signal. | Turn off Mono Audio and remove nonessential adapters before repeating the test. | Compare mono and stereo |
| 03Only one physical side produces any signal. | Balance, a partial connection, damaged cable, silent amplifier channel or failed driver can remove one side. | Center balance, reseat the connection and compare the device on another source. | Diagnose the silent side |
| 04Both sides work, but stereo is clearly off-center. | Unequal system balance, speaker distance, headphone seal or room reflections can shift the perceived center. | Keep volume fixed, center the balance control and repeat from a symmetrical position. | Fix unbalanced audio |
VARIABLES / 04
Why results can vary
The generated signal stays controlled; the physical device, room and system path can still change what reaches you.
Mono Audio
System accessibility settings can combine left and right before the signal reaches the selected output.
Physical orientation
Reversed earcups or speaker placement produces a swapped result even when the digital routing is correct.
Adapters and interfaces
Contact standards and routing matrices can combine, reverse or drop channels.
Built-in mobile speakers
Phone and tablet speakers may have different positions and capabilities, so equal loudness is not guaranteed.
LIMITS / 05
Browser limits and safety
Left Right Audio Test questions
Why are left and right reversed?
Headphones may be worn backward, analog plugs may be swapped, or an interface routing matrix may be reversed.
Why is everything centered?
Mono accessibility mode, a mono speaker or a channel-combining adapter may be active.
Does this work on phones?
Yes, with built-in speakers or connected headphones, although some phones intentionally use asymmetric speakers.