Loudness is the primary psychological correlate of intensity. When the intensity of a sound increases, loudness increases. However, there exists no simple one-to-one correspondence between loudness and intensity; loudness can be changed by modifying the frequency or the duration of the sound, or by adding background sounds. Loudness also changes with the listener's cognitive state. Loudness provides a basic reference for graduate students, consultants, clinicians, and researchers with a focus on recent discoveries. The book begins with an overview of the conceptual thinking related to the study of loudness, addresses issues related to its measurement, and later discusses the physiological effects of loud sounds, reaction times and electrophysiological measures that correlate with loudness. Loudness in the laboratory, loudness of steady-state sounds and the loudness of time-varying sounds are also covered, as are hearing loss and models.
The topic of loudness is of considerable concern both in and outside of research laboratories. Most people have developed an opinion about some aspect of loudness, and many complain about the loudness of background sounds in their daily environments and their impacts on quality of life. Moreover, such sounds interfere with the ability to hear useful sounds, and such masking can be especially problematic for people with hearing losses, children, older adults, and non-native speakers of a language.
At the same time, not all loud sounds are undesirable. Some loud sounds are important for human well-being, such as warning signals, whereas other loud sounds, such as music, can be pleasurable. In fact, loudness is essential for enjoying the dynamics of music. Thus, loudness is a pervasive and complex issue, and one that needs to be examined from a wide range of perspectives, and that is the purpose of this volume.
Research in loudness has been performed in many countries, and this volume is an international endeavor with authors from Europe, Japan, and the United States, making the volume an attempt to provide a global network of information about loudness. The editors are very pleased to be able to bring together information on many aspects of loudness in this one volume, as well as to highlight approaches from many different perspectives.
