ABSTRACT
This chapter looks at a variety of applications that combine both acoustic and psychoacoustic knowledge to achieve a specific audio objective. It describes the listening room design, audiometry, psychoacoustic testing, filtering and equalization, public-address systems, noise-reducing headphones, acoustical social control devices and audio coding systems. The chapter examines various techniques for achieving a good acoustic environment for hearing both stereo and multichannel music. Normal stereo signals do not reproduce correctly on headphones, and binaural recordings do not reproduce correctly on normal stereo equipment. The simplest such system is stereophonic reproduction, which uses two spaced loudspeakers to provide the illusion of sound sources in front of the listener. Spatial and so-called three-dimensional audio reproduction is an essential aspect of the enjoyment of sound, whether it is on a personal player via headphones, at home, or in the cinema. Wavefield synthesis can provide realistic sound fields, but the large amount of speakers and processing required limit its broader application with technology.
