paragraph: A friend whispers to you in class. You can barely hear them. To hear better you have to lean very close to hear what hes saying. Later that day, your friend shouts to you across the football field. Now his voice is very loud. You have no problem hearing him clearly even though hes many meters away. Obviously, sounds can vary in loudness. Loudness refers to how loud or soft a sound seems to a listener. The loudness of sound is related to the intensity of sound. Intensity is a measure of the amount of energy in sound waves. The unit of intensity is the decibel (dB). The intensity of sound waves determines the loudness of sounds, but what determines intensity? Intensity is a function of two factors. First, the amount of energy contained in the sound waves. Second, how far away you are from the source of the sound. Remember that sound waves start at a source of vibrations. Those sound waves spread out from the source in all directions. The farther the sound waves travel away from the source, the more spread out their energy becomes. 
question: How do sound waves move from the source of vibrations?
answer: In all directions