Hi @bigmqama, We moved your post to the Losing hearing because of brain tumor discussion where you started your discussion so that the other members can offer some suggestions or help answer your questions. I'm not sure of the round device that you wear around your neck is but I did find some information that may explain different options that may be available to help.

Assistive Devices for People with Hearing, Voice, Speech, or Language Disorders:
-- https://www.nidcd.nih.gov/health/assistive-devices-people-hearing-voice-speech-or-language-disorders

You may also be interested in the discussions under the Hearing Loss group here:
-- https://connect.mayoclinic.org/group/hearing-loss/

Are you able to call your doctor back and ask more questions about the device he suggested or more about what type of deaf education he was referring to?

@bigmqama, I don't know of a vibrating device that you wear around your neck but if you have a smartphone, you can set your phone to vibrate and set an alarm. You should do several tests to make sure it works as expected.
Tony in Michigan

@bigmqama, a thought just occurred to me. Maybe your doctor was referring to the Ditto? It's a small vibrating device that comes with a wrist strap but could be placed around the neck somehow, I suppose. The Ditto requires a smartphone to set the alarms though.
Tony in Michigan