Welcome to AD. Just to let you know, this thread was from 2012. When reading, keep date in mind cause a lot of people aren't on here much anymore and are unlikely to respond.
Also if they would do a search, there are answers all over this forum. There is even a thread that provides links.
On top of that, teachers need to stop with this assignment unless they are willing to provide people they can contact to ask.
https://www.alldeaf.com/community/threads/students-your-questions-answered-here.98667/
Welcome and here's a link with answers to questions in the past. You should be able to find answers to your questions.
Already added website on another thread but will post on here also.
https://www.sonicalert.com/
They do offer listening devices.
Also you can check this website and contact them. They may be able to help you with what you need to get/keep a job and to be safe at home...
Normally caller ID is before the phone so I would take wire from the wall and plug it into caller ID then plug new wire to what the old wire was in.
If current is wall to phone then new is wall to caller ID to phone.
Hover over name and small window should popup and click on new conversation. If not there, I think you have to have certain amount of posts before you can send one.