static File flite_makeWAV(S voice, S text) {
  if (!isOnPATH("flite")) fail("flite not installed");
  File wavFile = javaxCachesDir("flite.wav");
  S cmd = "flite";
  if (nempty(voice)) {
    File f = flite_findVoice(voice);
    cmd += " -voice " + (f != null ? platformQuote(f) : voice);
  }
  cmd += " -t " + platformQuote(text) + " -o " + platformQuoteOpt(wavFile);
  backtick(cmd);
  ret wavFile;
}