错误：不兼容的类型：无法转换ServiceCall <inputstream>

Question

我收到此错误。请帮我弄明白为什么？

  

错误：不兼容的类型：ServiceCall<InputStream>无法转换

play.setOnClickListener(
    new View.OnClickListener() {
        @Override public void onClick(View v) {
            new SynthesisTask().execute(reply.getText().toString());
        }
    }
);     

private class SynthesisTask extends AsyncTask<String, Void, String> {

    @Override protected String doInBackground(String... params) {
        player.playStream(textService.synthesize(params[0], Voice.EN_LISA));
        return "Did synthesize";
    }
}