freeswitch/conf/insideout/lang/fr/fr.xml

<include>
  <language name="fr" sound-path="/snds" tts-engine="cepstral" tts-voice="david">
    <X-PRE-PROCESS cmd="include" data="demo/demo.xml"/>
    <!--voicemail_fr_tts is purely implemented with tts, we need a files based implementation too -->
    <X-PRE-PROCESS cmd="include" data="vm/sounds.xml"/>
  </language>
</include>