Acoustic echo cancellation (AEC) is audio processing that removes the sound of the far end's voice from your microphones, so remote callers don't hear their own words echo back a moment later. Your room's speakers play the remote person's voice, the mics pick it up again, and AEC subtracts it before your audio is sent back.
How AEC works
- The system knows exactly what it is sending to the speaker (the "reference signal").
- It models how that sound travels around the room and arrives at the mics, including reflections off walls, glass and the table.
- It subtracts the predicted echo from the mic signal in real time.
- A second stage (often called residual echo suppression or non-linear processing) cleans up what the model missed.
- The model keeps adapting as people move, doors open and the room changes.
The hardest moment is double-talk, when people at both ends speak at once. Good AEC keeps both voices audible (full duplex). Weaker AEC ducks one side, which makes conversation feel clipped. See what is full duplex audio.
Why echo is a problem in meeting rooms
Echo almost always happens at the far end of the call because of a problem in your room. The remote person hears themselves; you hear nothing wrong. Common causes:
- Mics and speakers that are separate devices, so neither knows what the other is doing.
- Laptop mic or speaker left active alongside the room bar.
- Two devices in the same room joined to the same call.
- Hard, reflective rooms with long reverb that AEC can't fully model. See room acoustics and RT60.
- Speaker volume turned very high.
To track it down, see how to fix echo on a conference call.
AEC vs echo (reverb) in the room
AEC removes the far end's voice from your mics. It does not remove reverb, the boomy sound of your own voices bouncing around a hard room. That is handled by acoustic treatment and, partly, by de-reverberation and noise suppression features. See noise suppression in meeting rooms and how to fix room echo.
Where AEC lives
| Setup | Where AEC runs |
|---|---|
| All-in-one video bar | Inside the bar, which controls both mics and speaker |
| Speakerphone | Inside the speakerphone |
| Bar + expansion mics from the same brand | In the bar, which treats the mics as one system |
| Ceiling mics + separate speakers | In a DSP or the mic itself, using a reference from the speaker feed |
| Laptop alone | In the meeting app (Teams, Zoom and Meet all apply their own) |
Meeting apps apply their own echo processing too. When a certified room device is in use, the app generally relies on the device's processing.
What to look for when buying
- One system for mics and speaker. All-in-one bars, speakerphones and same-brand expansion mics handle AEC for you.
- Platform certification (Teams, Zoom, Google Meet) indicates the device met that platform's audio tests. See Teams Rooms certified devices.
- Ceiling or pro-AV mics: confirm where AEC happens and that a reference signal from the speakers is wired in.
- Don't mix random mics and speakers from different devices without a DSP.
Products that handle echo cancellation
Every conference device on our site processes its own mics and speaker together. Common choices:
- Video bars: Logitech Rally Bar, Poly Studio X52, Yealink MeetingBar A40. See best video bars.
- Speakerphones: Jabra Speak2 75, Poly Sync 60. See best speakerphones.
- Ceiling mics for larger rooms: Yealink CM20, AVer FONE700 (ceiling speakerphone with DSP hub).
Hearing echo you can't fix? Describe the room and devices and we'll suggest what to change.
Related guides
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