Ionic record audio (error)

home.ts

import { IonicPage, ModalController, ToastController } from 'ionic-angular';
import { Component } from '@angular/core';
import { Media, MediaObject } from '@ionic-native/media';
import { File } from '@ionic-native/file';
import { UserProvider } from '../../providers/user/user';

@IonicPage({ segment: 'index' })
@Component({
  selector: 'page-home',
  templateUrl: 'home.html'
})
export class HomePage {
  didLeave: boolean = false;
  isRecording: boolean = false;

  currentRecording: MediaObject;

  constructor(private media: Media,
              private user: UserProvider,
              private file: File,
              private modalCtrl: ModalController,
              private toastCtrl: ToastController) {
  }

  ionViewCanEnter() {
    return this.user.isAuthenticated();
  }

  ionViewWillLeave() {
    this.didLeave = true;
    this._stopRecording();
  }

  private getFileDirectory() {
    return this.file.tempDirectory || this.file.dataDirectory;
  }

  private getFileName() {
    return 'file.mp3';
  }

  private getFilePath() {
    return this.getFileDirectory() + this.getFileName();
  }

  async startRecording() {
    try {
      console.debug('createFile', this.getFileDirectory(), this.getFileName());
      await this.file.createFile(this.getFileDirectory(), this.getFileName(), true);

      console.debug('createMedia', this.getFilePath());
      this.currentRecording = this.media.create(this.getFilePath());
      this.currentRecording.onSuccess.subscribe(() => {
        this.currentRecording.play();
        console.log(this.currentRecording.getDuration()); // -1

        if (!this.didLeave) {
          this.modalCtrl.create('AddAudioModal', { file: this.getFilePath() }).present();
        }
      });
      this.currentRecording.onError.subscribe((err) => console.error(err));
      this.currentRecording.startRecord();
      this.isRecording = true;
    } catch (err) {
      console.error(err);
      this.toastCtrl.create({
        message: err,
        duration: 3000
      }).present();
    }
  }

  private _stopRecording() {
    this.currentRecording.stopRecord();
    this.isRecording = false;
  }

  stopRecording() {
    this._stopRecording();
  }
}