var texture1 : Texture2D;
var texture2 : Texture2D;
var AudioFile : AudioClip;
var alreadyUpdated = false;

function Update() {
    if (!alreadyUpdated && Input.GetKey(KeyCode.X)) {
        alreadyUpdated = true;    
        audio.clip = AudioFile;
        audio.Play();
        RenderSometing();
    }
}

function RenderSometing() {
    yield WaitForSeconds(1);
    renderer.material.mainTexture = texture1;

    yield WaitForSeconds(1);
    renderer.material.mainTexture = texture2;
}