The effects of noise on human beings have been well documented. Environmental psychologists, as well as researchers in other fields, have shown the degrees to which unwanted sounds in the built environment have compromised the health and well-being of city dwellers and suburbanites, of children and the elderly, of workers and stay-at-homes. Cultural, class, and generational differences are reflected in this research, as one person's music becomes another's noise. Design solutions vary not only according to perception, but also, and more importantly, according to where the sounds occur and to whom. A critical factor for understanding the role of design in relationship to both noise and sound lies in the division between public and private as sources.