Someone is standing 100ft. away from a speaker. They know the sound is coming from the speaker.?

However, unable to hear sound because it is too soft. Explain in terms of acoustics what is preventing the sound from reaching the person. There is nothing between person and speaker. Include in answer a typical propagation of sound ie: displacement, inertia, elasticity, domino effect, maximum positive and maximum negative displacement, periodic and simple harmonic motion. Also, explain why signal may not be reaching (hints: damping, small amplitude and resistance)