First here is the question: Who will hear the voice of a singer first? A person in the balcony 50m away from the stage, or a person 3000km away at home whose ear is next to the radio? How much sooner? Assume the mic is a few cm from the singer and the temperature is 20 degrees celcius. Now I was able to calculate how long it would take for the person 50 m away to hear it, but I don't know how to find out how long it will take for the second person to hear it. Please help me. Which equation do it use?