TABLE OF CONTENTS There have been extraordinary advances in the quality of the hardware in our audio systems, but less progress has been made in improving the quality of the acoustical pathway which all sound must travel from the loudspeaker to our ears. Once the sound has reached our ears there are still many psychoacoustical factors that determine how we perceive the sound. Much psychoacoustical research is now being vigorously pursued to understand how the mind perceives sound. Between the hardware and the perception of sound there is still that analog sound-transmission path in which many distortions arise. The remainder of this book is devoted to acoustic distortions and the new tools and computer programs which have appeared to measure and model them.
There are three psychoacoustic perceptions that are affected by acoustic distortions: frequency response or timbre, imaging, and spatial impression. Frequency response should be familiar by now. Good, clean high and low frequencies with a uniform response may be a goal, but timbre, or overall recognition and appreciation of the harmonic content is that for which we are striving. As we listen to the musicians we form a mental image of those producing the music. The image can be very vivid when things are adjusted properly. The size and shape of the sonic source are pictured as well as its height, depth, and width. New discoveries relate image formation to specific early reflections of the sound from the sidewall in an almost...
