hiː ɪz ˈeɪbəl tə mˌeɪk hɪmsˈɛlf hˈɜːd tə ðˌɛm bˌʌt ðeɪ kænˈɑːt spˈiːk tə hˌɪm, ɔːlðˈoʊ ðeɪ mˈeɪ mˌeɪk sˈaɪnz ɔːɹ mˈaʊθ wˈɜːdz.
He is able to make himself heard to them but they cannot speak to him, although they may make signs or mouth words.