The document describes an experiment where a sister listens to different tones in each earbud. The right earbud plays a 500Hz tone and the left plays a 503Hz tone, creating a 3Hz beat frequency. It is expected that she will raise her hand every 3.33 seconds as she hears 10 beats. If the right tone increases to 501Hz, the beat frequency decreases to 2Hz. As a result, the time between each hand raise is expected to increase to 5 seconds.