Have you tried IP Relay yet?

  It is now possible for people with hearing loss to make IP Relay calls through the internet. At this
  time (3/30/06), there is no charge for this service. That may change with no prior notice on this information  page!
Take notice of this. DefBird is not recommending any service and is not responsible for anything that may occur due to your use of this information, including charges that you may accrue.

Some companies currently providing IP Relay Service and their links are:

Hamilton:  http://www.hiprelay.com/

  Verizon:  http://www.ip-relay.com/index.html

      Sprint:   https://www.sprintip.com/index.html  

Have you tried CapTel Phone Service?

Most states have a program that distributes  telephone equipment free to people who have disabilities that require these special  accommodations. CapTel phones are very useful to people with hearing loss if they can speak well. Texas provides this phone free and has CapTel Relay service for its residents with hearing loss. Check HERE for info on your state.

Telecommunications:   

What Is Relay Texas & 7 1 1?

CapTel - What is Captioned Telephone?

Sprint Relay Services

Thank You!