USB-C headset not working for phone calls

[Eric BF]

Hello all,

TL;DR: none of my USB-C headsets can be used for phone calls while the 3.5mm audio headsets work just fine. Can I use USB-C headsets for calls?

I have searched the forum to no avail. Sorry if I missed an obvious post somewhere.

Longer story: when I bought my Gemini back in the dim and distant past, I installed Linux and never tried the Android OS. However, my main phone has been stolen and I needed something to replace it. So I've started using the Gemini as my phone now and this meant using Android. I've managed to get everything set up to my satisfaction (after a bit of a techno-shock moving from Android v12 back to v8...) except for phone calls. Although 3.5mm audio headsets work, they have the noise issue which I find quite annoying. The USB-C headsets do not have this problem but I cannot use them during calls.

Otherwise, I'm actually quite happy with the Gemini as my phone although I miss Linux...

Thanks for listening!

[Varti]

I have never used an USB-C headset, but I have done some digging and found this article:

https://www.androidauthority.com/usb-c-audio-guide-headphone-jack-943393/

It seems that USB-C audio support on Android is messy on any device.

Do you know if your headsets are active or passive? If they're all active, they might not work since the Gemini might not support Audio Accessory mode, I can't confirm this as I have not found any reference in the forum.
Do your headsets work on other smartphones?

Another related article on Android Authority:
https://www.androidauthority.com/usb-audio-class-android-893412/

A more recent one, claiming that "USB-C Audio is basically dead" due to lack of standardization:
https://www.androidauthority.com/state-of-usb-c-870996/

Varti

[Eric BF]

Thank you for the links. Depressing reading...
In answer to your questions:

• the headsets (I have 2) are passive
• the headsets worked just fine on a top end Samsung (the one that got stolen)

Thanks again. I'll use the 3.5mm headset I have, ignoring the noise when not actually in use.

[Daniel W]

According to the usb-c-audio-guide, referenced above, a "passive" USB-C headset relies on digital-to-analog (and vice versa) chips inside the phone to offer (and accept) analog signals via the otherwise digital USB-C connector. Phone makers can implement this via the Audio Adapter Accessory Mode or some proprietary hack. Either way, switching a USB port over to analog audio, requires some extra chips, which may fit the component budget of top end Samsungs, but I doubt Planet can afford them, especially as their devices already has dedicated analog headset jacks.

If you can get any analog USB-C audio out of your Gemini, then, the required chips must somehow be there. In such case, I'd think it's a software issue, of which Planet devices has plenty... but if your passive USB-C headset just doesn't work in the Gemini, I don't think it ever will. Maybe if you could find a digital-to-analog dongle, but then that needs to work with the Gemini...

I am very aware of the background noise made by the Gemini, when no other sounds are playing. To the best of my (limited) knowledge, that is a software issue. The Gemini powers down parts of its audio circuitry when not in use, but not all of it. This, apparently, leaves the input to the headphone amp floating, making it susceptible to pick up all sorts of digital noise from other circuits. My Cosmo sometimes does that, but the Gemini does it all the time.

The only crude workaround I found was to start an app that essentially plays digital silence (I toyed with a freeware synth) but as soon as it lost focus, the noise was back. Maybe a media player that can work in the background, but I don't know how that will affect battery life or the ability of the device to play other sounds.

OT: Back in my C64/128 days, I actually made use of similar background noise to get clues about what the computer was doing. It sometimes blanked its video output to gain a tad of performance when doing intense stuff. Tight loops tended to sound different than general processing or a stalled CPU, so sometimes I could hear when I needed to reach for the reset button...