docs: def phonex(word, language="english"):
      """
      Short for phone index, maps a word onto a sequence of phone clusters
      Strips non supported characters (for english, non alpha characters)
      """
      phone_variants = phoneticize(word)
      mappings = cluster_phones(language)
      results = []
      for phone_variant in phone_variants:
          try:
              phonex_variant = tuple([mappings[phone] for phone in
                                      phone_variant])
              results.append(phonex_variant)
          except:
              print('Error:', word, phone_variant)
              exit(1)
      return results