On a video call, the other person's voice comes out of your speaker… and leaks straight back into your mic. Without a fix, they'd hear themselves as an annoying echo! Phones cancel it by a clever trick: they already know what came out of the speaker, so they subtract it back out.
🟦 Far voice = what came out of your speaker. 🟥 Your mic = it hears that voice bounce back (delayed & quieter) — the echo. The AEC guesses the echo's delay and volume, and subtracts it → 🟩 clean. Tune the two sliders until the echo meter hits zero!
estimated echo delay (how long the bounce takes)
estimated echo volume
You just matched the echo by hand. A real AEC has to do this automatically and continuously, because the echo changes when you move your phone, change volume, or the room changes. That's why it uses an adaptive filter that keeps re-learning the echo path many times a second.
You matched the echo's delay & volume by hand — great for seeing the idea. But the real echo keeps changing, so pros make it automatic:
✅ Shows exactly how AEC works. ⚠️ Only cancels if nothing moves or changes.
Algorithms that re-learn the echo path many times a second as you move the phone. ✅ Handles real, changing rooms — every phone uses this. ⚠️ Math-heavy.
AI handles the hardest cases: speaker distortion and double-talk (both people speaking). ✅ Cleanest calls. ⚠️ Needs a model + compute.
You performed Acoustic Echo Cancellation — the trick that keeps every call from echoing, by subtracting the known speaker sound back out of the mic.