Q: Does Apple support RTT?

   I am hearing impaired, but I can enjoy TV.  I can understand much of the (audible) dialog, but some is not clear to me.  But, with Closed Captioning (CC) I can glance down at the on-screen text to get more information.

  I  think that something like that might available for telephone conversation.  I have read about Real  Time Text (RTT). That sounds like it could augment voice calls.

   I believe that that capability might be already included in computers.  I found an Apple web page that seemed to say that that was possible, but I lost the URL and can’t find it again.  One thing I remember was that an “apple modem tool” might be needed  - but I can’t find that (Device ?, Software ?) again anywhere.

   I would like to be able to use my Mac (Mac Pro) for RTT, if possible.  I’d appreciate any light you  could shed on this issue.

       Glenn Haste