Ember - Pass Event and Other Parameter to Action Handler

In my Ember component, I have a list of strings, and a function that update the string at certain index of the list.

animals: computed(function() {
    return ["dog", "cat"];
}),

updateAnimal(value, index) {
    this.animals[index] = value;
},

In my hbs, I render the list of strings into text fields, within a #each loop. When I focus-out the text field, I want to update the string at the certain index.

    <textarea
        value=
        
    />

But how can I pass in the index to the handler as well? In other words, how can I pass the event and some extra parameter at the same time? Thanks a lot for answering my question!!