Required hardware forSpeakup

[Krekan]

Hi everyone, I have read about possibility to have talking Linux and I am interested of what equipment should I have (syntesizer) to run it. I use talking software for Windows now (wintalker) and I 'd like to start with linux.
I used linux from shell before but I want to have my own linux on my home system. Why do I have to have syntesizer when I have soundcard? On Windows when i use wintalker I don't have to use any syntesizer.
Thanx for response
Krekan