Put sound in app notifications

I'm having trouble with my app, I'm trying to send notifications to mobile devices, notifications come in but they do not have a sound and I need them to make the sound to get attention. I have looked at some codes, but I did not understand / could not implement them.

public static void sendPush(final String title, final String message, final String id, Object... args) {
    if (!Utils.isEmpty(id)) {
        ConfigUtils cfg = ConfigUtils.get();
        String serverKey = cfg.get("gcm.server.key", "CHAVE-API");

        if (serverKey == null) {
            LogUtils.info("API Key não encontrada, registrar app em https://developers.google.com/mobile/add?platform=android&cntapi=gcm");
            return;
        }

        Thread thread = new Thread(new Runnable() {

            @Override
            public void run() {
                try {
                    HttpParams myParams = new BasicHttpParams();

                    HttpConnectionParams.setSoTimeout(myParams, 10000);
                    HttpConnectionParams.setConnectionTimeout(myParams, 10000); // Timeout

                    String url = GCM_URL;
                    DefaultHttpClient client = new DefaultHttpClient(myParams);
                    HttpPost post = new HttpPost(url);
                    BasicHttpContext localContext = new BasicHttpContext();
                    JSONObject mainData = new JSONObject();
                    try {
                        JSONObject data = new JSONObject();
                        data.putOpt("text", message);
                        data.putOpt("title", title);

                        JSONArray regIds = new JSONArray();

                        regIds.put(id);
                        mainData.put("registration_ids", regIds);
                        mainData.put("notification", data);
                        mainData.put("content_available", true);
                        mainData.put("priority", "high");

                        if (args != null && args.length > 0) {
                            Map toMap = Utils.toMap(args);

                            toMap.put("coldstart", true);
                            toMap.put("foreground", true);

                            mainData.put("data", toMap);
                        }

                    } catch (JSONException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }

                    StringEntity se = new StringEntity(mainData.toString(), "UTF-8");
                    post.setEntity(se);
                    post.addHeader("Authorization", "key=" + serverKey);
                    post.addHeader("Content-Type", "application/json");
                    post.addHeader("Accept", "application/json");
                    client.getParams().setParameter(ClientPNames.COOKIE_POLICY, CookiePolicy.RFC_2109);
                    HttpResponse response = client.execute(post, localContext);

                    BufferedReader rd = new BufferedReader(
                            new InputStreamReader(response.getEntity().getContent()));
                    StringBuilder result = new StringBuilder();
                    String line;
                    while ((line = rd.readLine()) != null) {
                        result.append(line);
                    }
                    System.out.println("Result: " + result + ", Code: " + response.getStatusLine().getStatusCode());
                } catch (Exception e) {
                    e.printStackTrace();
                }

            }
        });
        thread.start();
    }
}