There's something about deep, deep cultural programming. Anything
spoken with a British accent just sounds infinitely cool. Everyone
uses the default voice for Asterisk and all of that – an American
male.

You want to install festvox-rablpc16k or festvox-rablpc8k in addition
to all the usual things you need for emacspeak. You'll also need
espeakf from CVS.

cvs -d:pserver:anonymous@espeakf.cvs.sourceforge.net:/cvsroot/espeakf login
cvs -z3 -d:pserver:anonymous@espeakf.cvs.sourceforge.net:/cvsroot/espeakf co -P espeakf
cd espeakf
sudo make install

One of these lines is responsible for setting up espeakf. I just can't
be bothered with figuring out which. ;) Probably the dtk-program line.

(setq dtk-program "/usr/share/emacs/site-lisp/emacspeak/servers/espeakf.pl")
(setenv "DTK_TCL" dtk-program)
(setenv "DTK_PROGRAM" dtk-program)

Then add this to your /etc/festival.scm:

(set! voice_default 'voice_rab_diphone)

Yummy British accent goodness.

Random Emacs symbol: mail-extr-disable-voodoo – Variable: *If it is a regexp, names matching it will never be modified.