Sound gets quicker and louder when the source of sound approaches you. When the source of the sound is stationary the waves will meet you at the sound they produced. If your friend were to run to you while making the sound of a siren, you would hear how the sound gets louder and quicker as your friend gets closer to you.
Click the link to play and learn about the Doppler Effect.
http://www.planetseed.com/relatedarticle/doppler-effect-train
http://www.planetseed.com/relatedarticle/doppler-effect-train
Question: If you were in you car and honk your horn, what would you hear?
By McKenna Malison