I'm using Archlinux on a Lenovo Thinkpad, which generally works great.
I have a lot of online meetings, and so I have a variety of bluetooth headsets to choose from. I use bluez and blueman with the blueman-applet to manage my connections, and then pulseaudio to do the actual audio routing from my applications (zoom, skype, you name it) to the devices.
Two headsets in question that I use are
- Bose QC35 II
- Google Pixel Buds A-Series
For either of these, whenever I connect to them, the audio profile selected by pulseaudio is "High Fidelity Playback (A2DP)", which is (as far as I understand) a Sink-only profile, so that's not too useful for me, because I also want to use the microphone.
For the Bose headset, it shows me that "Headset Head Unit (HSP)" is unavailable. I don't know why that is, but I suppose this is just a property of the headset that they don't support that profile.
Hence, I have to change to "Handsfree Head Unit (HFP)" in order to actually make the microphone work, which is fine.
Now, here's the issue: Whenver I make that switch, I all of the sudden hear a very low-level, but clearly recognizable static noise, which is pretty annoying. I'm sure this is a software-side problem, because it instantly goes away if I switch back to the A2DP profile. On the other hand, it also seems to be connected to the specific hardware, because I don't encounter that behavior with my Pixel Buds.
I assume there is some bug in the default configuration of bluez/blueman that causes this behavior, because the headset works perfectly when connecting to my phone.
So, in summary, my question is: Where can I find information about the configuration options for my headset, and does anyone have an idea what specifically might be causing the static noise and how I could get rid of it?
