Hi. Thanks for your reply. You've tried this with a nexus 5 and SailfishOS? it's so rare, it makes the same noise with a headset and carsystem. I've changed bluetooth connection mode to car system, headset and so on...and still the same. I'm sure it's not the hardware of my nexus (works excellent with android or firefox os) or the devices (they work ok with other phones). And the noise is only on my side, so the voice of the caller is too hard to hear because of that. I think it's the codec that compress the voice when sending it to the device. I'll dig on pulseaudio 6. Please try to test it with another device if you can, and let me know the results. Pablo.