I use this 'hearing aid' => Jabra Talk 25 Bluetooth JABRATALK25BK
And when I leave from my Micra vehicle, I'm still connected to my device, camera equipped personal portable multimedia device, which even has build in phone on it...
I use umi quad driver headset from amazon.
With XJYL Receiver also from amazon.
I have only tested it briefly with phone/head unit.
It last 4 hours the receiver so really needs dedicated USB to keep using.
The upside to this setup is I found I can direct plug mp3 player for OTG listening.
Can also use for hifi making it Bluetooth compatible with both the phone and mp3 player as the headphone jack doubles it's connectivity options.
Aux port is needed for this to work with head unit.
My reason for this type of setup was no compatibility from android to head unit.
An air pod or Iphone will work directly via usb but I do not have such a device.
Nor do I wish to have cables hanging about as this isn't ideal.
I can say so far it's been a good choice though yet to test as a regular headset for calls.
My previous method was and still mostly is just directly inserting usb stick or mp3 player to head unit.
I have not used a CD player for sometime now and not once in the micra.
A headset is what they call them or earphone ear buds.
Hearing aids are for the hard of hearing.
And don't usually have Bluetooth here in UK.