An example of how to create Pause and Mute buttons for your Phaser game.

pause-and-mute-buttons.js

/////////////////////////////
//CREATE SOUND TOGGLE BUTTON
/////////////////////////////
this.soundButton = this.game.add.button(this.game.world.centerX + 240, this.game.world.centerY - 290, 'sprites', this.toggleMute, this, 'sound-icon', 'sound-icon', 'sound-icon');
this.soundButton.fixedToCamera = true;
if (!this.game.sound.mute) {
    this.soundButton.tint = 16777215;
} else {
    this.soundButton.tint = 16711680;
}
//////////////////////
//CREATE PAUSE BUTTON
//////////////////////
this.pauseButton = this.game.add.sprite(this.game.world.centerX + 320, this.game.world.centerY - 280, 'sprites', 'pause-button');
this.pauseButton.inputEnabled = true;
this.pauseButton.fixedToCamera = true;
this.pauseButton.events.onInputUp.add(function() {
    this.game.paused = true;
    this.pauseButton.tint = 16711680;
}, this);
this.game.input.onDown.add(function() {
    if (this.game.paused) this.game.paused = false;
    this.pauseButton.tint = 16777215;
}, this);


...

toggleMute: function() {
    if (!this.game.sound.mute) {
        this.game.sound.mute = true;
        this.soundButton.tint = 16711680;
    } else {
        this.game.sound.mute = false;
        this.soundButton.tint = 16777215;
    }
},