The compressions in a sound wave are very close together, and more energy is supplied by the vibrating source. Which statement best describes how this will affect the wave and what you hear?

a. The wavelength will increase, and the sound will become louder.

b. The amplitude will increase, and the sound will become louder. 

c. The frequency will increase, and the pitch will become higher. 

d. The intensity will increase, and the pitch will become higher.