I found some information that I think will do what you are looking for. I have tried and had success with the following here. Please try it and see what you think.
If you want your Raspberry Pi to be able to speak to you, in multiple languages, do the following.
In a terminal window type the following (each on a separate line)
sudo apt-get install alsa-utils
sudo apt-get install mplayer
Then lets look at the modules by typing this in a terminal
sudo nano /etc/modules
After typing the above command check the file that opens to see if it shows the following:
snd_bcm2835
if it does exit. If it DOES NOT add it.
Then add a line to the mlayer configuration by typing this in a terminal:
sudo nano /etc/mplayer/mplayer.conf
Add the following. If you aren't sure where to put it, the bottom works fine
nolirc=yes
*Be sure to save your changes. It should be CTRL+X to exit and will prompt you to save your changes in nano
Then for the test do the following
nano speech.sh
Then put the following in a new file called speech.sh and save it.
#!/bin/bash
say() { local IFS=+;/usr/bin/mplayer -ao alsa -really-quiet -noconsolecontrols "http://translate.google.com/translate_tts?tl=en&q=$*"; }
say $*
Helpful tip, be sure to remember to change the permissions to read from the file
chmod u+x speech.sh
Then type the following as an example to hear audio on your pi.
./speech.sh what do you think your doing, dave
While I know this has the ability to translate as well, you can find more about that on the Google Translate help pages.