How to mute and unmute sound in Angular2?

I have a sound in my Angular project, like this:

introInfo() {
   this.audio.src = '../assets/sound1.wav';
   this.audio.load();
   this.audio.play();
 }

 feedbackInfo() {
   this.audio.src = '../assets/sound1.wav';
   this.audio.load();
   // auto-start
   this.audio.play();
 }

And I would like to be able to mute all sounds. If I click the button in my template:

<img class="grow" id="mute" [src]='mute' (click)="muteF()"/>

How could I write my function muteF? I would like to mute if I click the button. If I click a second time, it must perform unmute.