Rohit is trying to tune an instrument. He strikes a tuning fork and then plays a note that almost matches it. Rohit hears the volume of the two waves beating, which sounds like "wah-wah-wah-wah."

The repeating “wah-wah” change in loudness is called beats. Beats occur when two sound waves have slightly different frequencies: as the waves alternately reinforce and cancel one another, the volume rises and falls. Therefore, the correct choice is “The two waves produced have different frequencies.”

AI-written and checked against the verified answer.