Can Google WebRTC in an Android app satisfactorily control echo and noise during a voice call between two devices 1 meter apart?

I used AI to translate my question from Chinese to English, so it might not sound very fluent. Please bear with me.

Currently, I’m using WebRTC in an Android app. When two devices are far apart, enabling the speakerphone for a call doesn’t produce echo or feedback. However, when the two devices are close to each other, like within 1 meter, there’s a loud feedback noise. I’d like to know whether this issue is due to incorrect usage on my part or if the AEC (Acoustic Echo Cancellation) and NS (Noise Suppression) in WebRTC are only capable of achieving this level of performance.
Thanks!

I want to know if WebRTC voice calls between two Android devices placed 1 meter apart can achieve satisfactory results: issues like feedback and noise are acceptable. 。