Is this the appropriate place to ask a question about use of Bluetooth devices for use at work with an Avaya 9650 IP Desk Phone?
Yes, does that phone have a headset port?
I’m using the Plantronics MDA200 switcher with a bluetooth BT300 plugged into it. It works very well. If you have a headset port there is probably a Plantronics EHS cable for your phone. You really need that cable or you will have to have a “lifter”, or take the phone handset offhook manually. With the cable in place you can just answer the phone from your hearing aid bluetooth device. Again, the cable is specific to each model of phone.