#$&* course PHY 202 I see that the amplitude controls the volume of the sound while the frequency controls the pitch. I also see that the sound moves in waves and takes a while between when the speaker emits a sound to when the listener hears the sound. The reflective surface shows me that like light waves, the sound waves can be reflected and cross each other’s path causing interference. I also see that without air, the sound wave cannot travel, leading me to believe that the sound wave cannot travel in a vacuum as there is nothing for the wave to travel through.