Have Ubuntu speak to you

Ubuntu includes a built-in speech synthesizer called espeak. It’s there
to work in partnership with the Orca screen reader, which provides
support for those who are partially-sighted,2 but it can also be called
from the command-line, as follows:

$ espeak "Ubuntu Kung Fu"

As you’ll be able to tell it’s not the most sophisticated speech synthe-
sizer in the world (it has a feel of Speak & Spell about it), but it can be
fun to play around with.
By simply typing espeak, and then hitting Enter , whatever you type
after this will be spoken. To quit, type Ctrl + d .
To switch voices, use the -v command option, but first you’ll need to
find-out the available voices, which can be done by typing espeak --
voices=en. For example, to have the phrase “How about a nice game of
chess?” spoken in a Jamaican voice, you could type:

$ espeak -s 140 -v en-westindies "How about a nice game ←֓
of chess?"

In the above example I also added the -s command option, by which
you can specify the speech speed in words per minute. The default
value of 170 tends to be a little fast, especially when it comes to longer
sentences.

Taken From Ubuntu Kungfu