Shaberu.vim is the wrapper of speech synethis. You can make your vim speak easily with Shaberu.vim.
Put following lines into your .vimrc.
NeoBundle 'Shougo/unite.vim'
NeoBundle 'Shougo/vimproc'
NeoBundle 'supermomonga/shaberu.vim'
Then, execute :Unite neobundle/update
If you use Mac OS X or Windows, you don't need to do anything. If you use other OS like Linux, you need to set g:shaberu_user_define_say_command.
let g:shaberu_user_define_say_command = 'saycommand "%%TEXT%%"'
Shaberu convert %%TEXT%% to the text to speak.
" Speak Japanese voice on OS X
let g:shaberu_user_define_say_command = 'say -v Kyoko "%%TEXT%%"'
Simplly, execute :ShaberuSay command to speak text.
:ShaberuSay Hi! I'm vim!
Shaberu.vim has more futures, like Mute toggle, outputter for QuickRun.vim , and others. See :h shaberu.