This is a free, online textbook from WikiBooks. According to the authors, "Acoustics (from Greek ακουστικός pronounced akoustikos meaning "of or for hearing, ready to hear") is the science that studies sound, in particular its production, transmission, and effects. Sound can often be considered as something pleasant; an example of this would be music. In that case a main application is room acoustics, since the purpose of room acoustical design and optimisation is to make a room sound as good as possible. But some noises can also be unpleasant and make people feel uncomfortable. In fact noise reduction is a major challenge, particularly within the transportation industry as people are becoming more and more demanding."