function Start () {
    audio.volume = 0;

}

function Update () {

if(Input.GetKey("a") && Input.GetMouseButton(1) || Input.GetKey("w") && Input.GetMouseButton(1) || Input.GetKey("d") &&         Input.GetMouseButton(1)
|| Input.GetKey("s") && Input.GetMouseButton(1) || Input.GetKey("w") && Input.GetMouseButton(0) || Input.GetKey("s") && Input.GetMouseButton(0)
|| Input.GetKey("w") || Input.GetKey("s")) {

    if(movement.grounded == true) {
        audio.volume = 1;
    }

    else {

        audio.volume = 0;
    }
}
else {
    audio.volume = 0;
}