[ILUG] Self-service phone system in Tax office

[Kevin Chen]

Hi Guys,

   I know this may not really relate to Linux, but I still wonder if anybody


here may know about it. The story is I ring the self-service phone number in
Tax

office yesterday, as usuall I follow the Computer order, then when I need to


provide my PPS number, I suprise I don't need to press any key, actually
just call it out

digi by digi, and the computer can understand  and accept it.

So I just wonder what kind telephone system behind all this? where can I
find more detail of it?

Regard,

Kevin