def ListVoices(voice_spec=None):
ppv = cListVoices(voice_spec)<EOL>res = []<EOL>i = <NUM_LIT:0><EOL>while ppv[i]:<EOL><INDENT>res.append(ppv[i][<NUM_LIT:0>])<EOL>i += <NUM_LIT:1><EOL><DEDENT>return res<EOL>
Reads the voice files from espeak-data/voices and returns a list of VOICE objects.

   If voice_spec is None then all voices are listed.
   If voice spec is given, then only the voices which are compatible with the voice_spec
   are listed, and they are listed in preference order.