Based on lectures given at a one week summer school held at the University of Southampton, July 2003.

This textbook provides a guide to the fundamental principles of acoustics in a straightforward manner using a solid foundation in mathematics and physics. It is designed for those who are new to acoustics and noise control, and includes all the necessary material for a comprehensive understanding of the topic. It is written in lecture-note style and can be easily adapted to an acoustics-related one semester course at the senior undergraduate or graduate level. The book also serves as a ready reference for the practicing engineer new to the application of acoustic principles arising in product design and fabrication.

Modern Methods in Analytical Acoustics considers topics fundamental to the understanding of noise, vibration and fluid mechanisms. The series of lectures on which this material is based began by some twenty five years ago and has been developed and expanded ever since. Acknowledged experts in the field have given this course many times in Europe and the USA. Although the scope of the course has widened considerably, the primary aim of teaching analytical techniques of acoustics alongside specific areas of wave motion and unsteady fluid mechanisms remains. The distinguished authors of this volume are drawn from Departments of Acoustics, Engineering of Applied Mathematics in Berlin, Cambridge and London. Their intention is to reach a wider audience of all those concerned with acoustic analysis than has been able to attend the course.

Principles of Musical Acoustics focuses on the basic principles in the science and technology of music. Musical examples and specific musical instruments demonstrate the principles. The book begins with a study of vibrations and waves, in that order. These topics constitute the basic physical properties of sound, one of two pillars supporting the science of musical acoustics. The second pillar is the human element, the physiological and psychological aspects of acoustical science. The perceptual topics include loudness, pitch, tone color, and localization of sound. With these two pillars in place, it is possible to go in a variety of directions. The book treats in turn, the topics of room acoustics, audio both analog and digital, broadcasting, and speech. It ends with chapters on the traditional musical instruments, organized by family. The mathematical level of this book assumes that the reader is familiar with elementary algebra. Trigonometric functions, logarithms and powers also appear in the book, but computational techniques are included as these concepts are introduced, and there is further technical help in appendices.

The purpose of this book is to j.ir€'~ 0l'l\' a new technique for the experimental investigation of the free wave model sound field of acoustics. The technique is based on the use of spherical harmonic functions of angle. Acousticians frequently encounter random sound fields whose properties may be closely modelled by use of the "free wave" field. This model field is defined by two basic statistical properties: stationarity in time, and homogeneity in space. Stationarity means that any single order statistic measured by a microphone in the field will be independent of the time at which the recording is taken, while homogeneity means that the measurement will also be independent of the mic- phone's position in the field. Furthermore, second order statistics obtained from the measurements of two microphones will depend only on the time lapse between the two recordings, and the relative spatial separation of the micro phones, and not on the microphones' absolute positions in space and time. The free wave field may also (equivalently) be pictured as a collection of plane sound waves which approach an observation position from all angles. These are the "free waves" of the title, with no correlation between waves at different angles and frequencies, although there may exist an angle-dependant plane wave density function. This is a measure of the density of sound energy arriving from different angles. The free wave field has proved to be a simple but remarkably powerful model.

No branch of classical physics is older in its origins yet more modern in its applications than acoustics. Courses on acoustics very naturally begin with a study of vibrations, as a preliminary to the introduction of the wave equations. Both vibrations and waves, of course, are vastly important to all branches of physics and engineering. But it is very helpful to students to gain an understanding of mechanical waves before trying to comprehend the more subtle and abstract electromagnetic ones. This undergraduate-level text opens with an overview of fundamental particle vibration theory, and it proceeds to examinations of waves in air and in three dimensions, interference patterns and diffraction, and acoustic impedance, as illustrated in the behavior of horns. Subsequent topics include longitudinal waves in different gases and waves in liquids and solids; stationary waves and vibrating sources, as demonstrated by musical instruments; reflection and absorption of sound waves; speech and hearing; sound measurements and experimental acoustics; reproduction of sound; and miscellaneous applied acoustics. Supplementary sections include four appendixes and answers to problems. Introduction. Appendixes. List of Symbols. References. Index. Answers to Problems.

Research and scientific progress are based upqn intuition coordinated with a wide theoretical knowledge, experimental skill, and a realistic sense of the limitations of technology. Only a deep insight into physical phenomena will supply the necessary skills to handle the problems that arise in acoustics. The acoustician today needs to be well acquainted with mathematics, dynamics, hydrodynamics, and physics; he also needs a good knowledge of statistics, signal processing, electrical theory, and of many other specialized subjects. Acquiring this background is a laborious task and would require the study of many different books. It is the goal of this volume to present this background in as thorough and readable a manner as possible so that the reader may turn to specialized publications or chapters of other books for further information without having to start at the preliminaries. In trying to accomplish this goal, mathematics serves only as a tool; the better our understanding of a physical phenomenon, the less mathematics is needed and the shorter and more concise are our computa tions. A word about the choice of subjects for this volume will be helpful to the reader. Even scientists of high standing are frequently not acquainted with the fundamentals needed in the field of acoustics. Chapters I to IX are devoted to these fundamentals. After studying Chapter I, which dis cusses the units and their relationships, the reader should have no difficulty converting from one system of units to any other.