如何在status bar中显示通知?

我在 activity 中创建了 notification

Notification n = new Notification.Builder(getApplicationContext())
    .setContentTitle("New mail from " + sender)
    .setContentText(subject)
    .setSmallIcon(R.drawable.notification)
    .build();

现在在status/notification bar 中如何显示通知，并且还带有声音？

NotificationManager notificationManager = (NotificationManager)context.getSystemService(Context.NOTIFICATION_SERVICE);
notification.sound = uri; //比如 Uri uri= RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
notificationManager.notify(0, notification);