Set default ringtone as local notification sound

Am using 3.2.2 sdk, Alloys and developing app for iPhone. I am using scheduleNotification to schedule some notifications in my app and for it I need to play device default ringtone as local notifications sound. Is it possible and if so is there anyway to set it. As far I searched we can't set/access default ringtone of iOS.

notify.scheduleLocalNotification({
        alertBody: "Test",
        alertAction: "Launch",
        userInfo: {},
        sound: **default sound to place here**,
        date: new Date(new Date().getTime() + 10000) 
    });