ParrotNotes

Audio Delay Test

Find out how far your sound trails the picture. Line up a beep with a flash for any headphones, TV or soundbar, or let the microphone time a click through your speakers. Everything runs in your browser.

Turn your device volume down before you press Start, then raise it until the beeps are clear.

A short beep plays once a second and the circle flashes. If you hear the beep after you see the flash, your sound is late. Drag the slider until they land together.

-100 to 500 ms. Watch the circle and listen at the same time; it helps to look slightly away and judge the moment of the click.

Sound is generated and analyzed in your browser. Nothing is recorded or uploaded, and the microphone is released when the test ends.

How to test your audio delay

  1. 1

    Pick a mode

    Sync check works with anything this device plays through: Bluetooth headphones, or a TV or soundbar it is connected to. Measure needs speakers and a microphone in the same room.

  2. 2

    Start quietly

    Turn the device volume down, press Start, then raise it until each beep is clear.

  3. 3

    Line up beep and flash

    If the beep comes after the flash, drag the slider right or tap +10 ms until both land at the same moment, then show your reading.

  4. 4

    Or let the microphone time it

    In Measure, allow the microphone. The page plays 5 clicks and reports the median round trip in milliseconds.

Checking that sound plays at all, or which side is which? Use the Sound Test or the Left Right Audio Test. For the microphone itself, run the Microphone Test.

How much delay people notice

Broadcast bodies have set limits for how far sound may drift from the picture. Positive means sound early, negative means sound late.

GuidelineSound early, at mostSound late, at mostWhat it is
ITU-R BT.135945 ms125 msWhere expert viewers began to notice
EBU R3740 ms60 msEnd-to-end target for European broadcast
ATSC IS-19115 ms45 msTarget for US digital TV
People are more forgiving of late sound than early sound, which matches everyday life: light arrives first, sound follows at about 3 ms per meter.

Why Bluetooth audio runs late

Wireless audio is compressed, sent in packets and buffered in the headphones so a dropped packet does not cause a gap. Each step adds time. In SoundGuys' 2021 tests on four Android phones, the averages were 308 ms with SBC, 316 ms with aptX, 324 ms with LDAC and 369 ms with AAC. That is two to three times the 125 ms at which ITU-R BT.1359 found lag becomes noticeable.

Those figures are from older phones on one platform, so your setup may be faster or slower. That is the point of testing it yourself: the reading here is your phone or computer, your codec and your headphones together.

What the microphone measurement includes

  • The whole round trip

    It times the click from the page to the speaker, through the air and back in through the microphone. The microphone's own input delay is part of the number, so the output delay alone is lower.

  • Speakers, not headphones on your head

    The microphone has to hear the click. With headphones on, it hears nothing and the trial fails.

  • Bluetooth headphones only if the mic hears them

    To time them, hold one earcup or earbud right at the microphone at low volume. If the browser picks the headset's own microphone instead, many systems switch it to a call mode, which changes the delay.

  • Filters are off

    Echo cancellation would remove the click, so the page asks the browser to turn it, noise suppression and auto gain off. Some systems ignore that request.

What to do with your reading

  • TVs and soundbars

    Look for a setting called lip sync, AV sync or audio delay. Many can only delay the sound, which fixes sound that arrives early; for late sound, try the soundbar's own setting or a wired connection.

  • Headphones

    A wired pair has no radio delay. Some wireless models offer a low-latency or game mode; the manual will say if yours does.

  • Editing, streaming and games

    Some editors, streaming tools and rhythm games have an audio offset or latency setting. Enter your reading there, then check by eye on a clap or a hard consonant. It changes what you hear while you work, not the saved file.

Need a steady tone to compare speakers by ear? Try the Tone Generator.

Recording calls or meetings?

Once your audio is sorted, the ParrotNotes app records, transcribes and summarizes your meetings, interviews and lectures.

Start free

Related tools

Audio Delay Test FAQ

Sources