Bluetooth Headset Microphone not detected in Kubuntu 22.04
Linux Troubleshooting
When connecting to a video conference the other day, I noticed that I only had sound output from my bluetooth headset, but the microphone was not detected.
It turned out to be a triviality, but it wasn’t so intuitive to figure out. Here is my headset connected to a Windows Machine for comparison. Here it seems to work just fine:
In Output settings for the headset, you will notice that it has 2 modes:
Actually they are Bluetooth Profiles:
The Profile with 2 channels is called A2DP=Advanced Audio Distribution Profile. That profile doesn’t support input sound but has superior output audio quality. It is better used for listening to music or watching videos.
The other profile that has only 1 channel is called HFP = Hands Free Profile. It supports microphone input but has inferior output audio quality. This mode should be used when making phone calls or joining a video conference.
Source: https://www.usa.philips.com/c-f/XC000008687/what-is-a-bluetooth-profile-hsp,-hsp,-a2dp,-avrcp
In Windows, these technical details are abstracted from the user and the headset is able to switch between the profiles automatically. That is why the output audio quality becomes degraded when a video conference starts.
Why there isn’t a mode that supports both good output and input audio quality is beyond my understanding of the technical limitations of Bluetooth. I would guess it has something to do with a limit of 2 channels. Anyway, back to Kubuntu:
At first, I didn’t notice the hamburger menu to the left of to the headset description. If you click on that, you can change the Bluetooth profile:
As you can see, Kubuntu shows the real names of the Bluetooth profiles supported by the system. Now the microphone is listed in available audio devices:
So in conclusion, Windows is a bit smarter when it comes to switching Bluetooth profiles, but at least we learnt something new. Next time I’ll buy a pair of Bluetooth headset, I will be interested in what profiles it supports.
One day I’m going to find out if Kubuntu can automatically switch Bluetooth profiles like Windows does.