I am developing an android application in which I have to play an alarm and set the reminder.
The Android AlarmManager doesn't actually ring an audible alarm. If you schedule an alarm the alarm manager will notify your app at the set alarm time by starting the
PendingIntent you've provided (in your case the AlarmService). It doesn't do anything more. If you want sound, your AlarmService should play that when the service is started. You can use the android mediaplayer for this.