Getting value inside of variable in Node.js

I have two speeches to select from for outputting in Alexa SDK e.g

const HI = 'hi'; const HELLO = 'hello'; 

I store the variable name in an array:

const speech = [HI, HELLO]; 

I process and get the index number of the speech I want to output. Now the problem is how to output the speech – ‘Hello’ in the following line of codes:

    return handlerInput.responseBuilder        .speak($  speech[1]);     },