There is a relay service (like AT&T and IP-RELAY) that allows 911 call. You can choose to register an account with them and input all your address in it so that it will facilitate 911 service better.
With a cell phone, you can dial 911 and leave it because most cellphones are equipped with GPS. Just yell at cellphone that you are deaf. I understand if you cannot talk very well but do the best you can. For example - "I DEAF. HELP! HELP! NEED HOSPITAL. <say your address>" meanwhile - try to find anybody (neighbor, bystander, etc.) to talk to cellphone for you.
You also should pre-program the message in your cellphone that will quickly translate into full sentence. For example - if your mom is prone to faint/heart attack, pre-program your message like this. typing "hhh" or "abc" will be automatically converted to "mom heart attack" and then send it to your cousin. Every second counts.
hope that helps.
