Ionic 3 local notification sounds not working

below is my code
notifications all are coming but sounds not working

this.localNotifications.schedule({
id: 1,
text: ‘Single ILocalNotification’,
vibrate: true,
sound: ‘file://assets/sounds/shorte.mp3’,
led:‘00FFFF’
});

please help i am trying from 2 days not working
checking android version android 8.0