With FN (FujiNet) you can now let your Atari speak. The Software Automatic Mouth (SAM) is implemented in FN as the P: device. Note: requires a XL/XE system.

OPEN #1,8,0,"P4:"
PRINT #1;"HELLO FROM SAM"

There is video showing the details of this implementation:

There is a lot more programming info and how to use phonemes on the FujiNet SAM Wiki page:

https://github.com/FujiNetWIFI/fujinet-platformio/wiki/Using-SAM-%28Voice-Synthesizer%29