Aurelia messaging app - Bell

messageBell.js

import {inject} from 'aurelia-framework';
import {EventAggregator} from 'aurelia-event-aggregator';

@inject(EventAggregator)
export class MessageBell {

   constructor(eventAggregator){
        this.eventAggregator = eventAggregator;
        this.audio = new Audio('newMessage.m4a');
    }

    attached(){
        this.newMessageSubscription = this.eventAggregator.subscribe('new-message', _ => {
            this.audio.play();
        });
    }

    detached() {
        this.newMessageSubscription.dispose();
    }
}