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Ever wondered how your microphone doesn’t pick up the sound from your speakers during calls, even though they are so close together? This is due to Acoustic Echo Cancellation (AEC)—a crucial technology used in audio processing to remove unwanted echoes from recorded signals.

https://github.com/siddu015/acoustic_echo_cancellation.git

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What is Acoustic Echo Cancellation (AEC)?

Imagine you are talking to a friend on a call. When your friend speaks, their voice plays through your speaker. But if your microphone picks up their voice again, it creates an echo, making the call sound bad. AEC works by detecting this unwanted echo and removing it in real-time, ensuring only your voice is transmitted.

How Does AEC Work?

1. Reference Signal: Before User1’s voice plays through the speaker on User2’s side, a copy of it is stored as a reference signal. This helps the AEC system identify and remove echoes.
2. Microphone Input: User2’s microphone picks up both User2’s voice and the unwanted echoes of User1’s voice coming from the speaker.
3. Echo Cancellation: The AEC system generates an inverted version of the echo using the reference signal and subtracts it from the microphone input. This leaves behind only User2’s voice.
4. Real-World Challenges: In actual environments, echoes change due to room acoustics, surfaces, and distances. The reference signal alone isn’t enough to fully cancel the echo.
5. Adaptive Learning (Convergence): The AEC system continuously adjusts and refines the echo removal process in real-time to match changing conditions, ensuring accurate cancellation.
6. Final Cleanup (NLP - Non-Linear Processing): Any remaining residual echoes that weren’t removed earlier are intelligently suppressed. This final step cleans up the audio and ensures crystal-clear voice transmission.

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For a clearer visual understanding, check this out!

https://youtu.be/BEBXj9A8jC8?si=4qTdrBpqA-K1y5BH

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Building AEC in Rust

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Reference to build this project.

Acoustic Echo Cancellation (AEC)

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We are going to build a basic Acoustic Echo Cancellation (AEC) system in Rust using adaptive filtering to minimize echo from speaker output in recorded audio. This system will capture audio from your microphone, process it to remove echoes, and play back the cleaned audio. What we’ll see

• Why traditional echo cancellation methods might not be ideal
• Setting Up Your Rust Project
• How we record, process, and play back audio
• Implementing adaptive filtering for effective echo cancellation

Why Not Use Direct Speaker Audio for Echo Cancellation?