You should use NotificationCompat.Builder as the Notification class is stripped of API level 20 and above
and use this piece of code, I hope it will work for u
NotificationCompat.Builder builder = new NotificationCompat.Builder(this);
builder.setSmallIcon(R.drawable.notificationg);
Bitmap icon = BitmapFactory.decodeResource(getApplicationContext().getResources(),
R.drawable.ic_launcher);
builder.setStyle(new NotificationCompat.BigPictureStyle().bigPicture(icon));
Intent i = new Intent();
PendingIntent pIntent = PendingIntent.getActivity(this, (int) System.currentTimeMillis(), i, 0);
builder.addAction(R.drawable.ic_launcher,"OK",pIntent);
Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse("http://www.google.com/"));
PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, intent, 0);
builder.setContentIntent(pendingIntent);
builder.setLargeIcon(BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher));
builder.setContentTitle(notificationTitle);
builder.setContentText(notificationMessage);
Uri alarmSound = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
builder.setSound(alarmSound);
builder.setSubText("Tap to go to link in notifications.");
NotificationManager notificationManager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
notificationManager.notify(NOTIFICATION_COUNT, builder.build());
The sound signal will work normally Uri alarmSound = RingtoneManager.getDefaultUri (RingtoneManager.TYPE_NOTIFICATION); builder.setSound (alarmSound);