No abstract

The first edition of this book was written in 1974, the ice age of signal analysis. The author's purposes then were to discuss the field of random vibration because it was not dealt with much in undergraduate schools of engineering at that time, and to illuminate spectral estimation based on the fast Fourier transform (FFT). He noted at that time that most users of the FFT have "incomplete understanding of the nature of the approximations involved.. ." and hoped the book would help. Maybe that edition did not help. Now, 20 years later, it is my opinion that few users of the FFT analyzer have evolved past Newland's estimation of the skills of most users. The second edition (1984) added multidimensional random vibration and added some programs; the third (1993) adds the concept of wavelet transform. This edition further fulfills the hopes expressed in the original work. The book discusses many important topics, some in more detail and some clearer than others. But taken together, this is a very good book. I list the contents of the book to show its comprehensiveness:

“Outdoor living” suggests voluntary exposure to weather and other stimuli, among them noise. The effects of noise on outdoor living are functions of societal factors, the purposes of being outdoors and, of course, the intensity, quality, and source of the noise. This paper discusses some of the concepts involved in relating noise to outdoor living, a brief history of the subject, and current research as reflected by the papers presented at the May 1978 ASTM Community Noise Symposium, as well as by other sources. Included are comments on community noise impact on hearing, human response to transportation noise, and speech interference and community annoyance.

Often, when a room is excited by a specified spectrum, the resulting spectrum differs in shape from that desired. Caused by the impedance of the space and by the objects within, in the past, the change has been accounted for by the use of a spectrum shaper before the noise generator, which was manually adjusted so that the desired shape and level of the output was achieved. This paper presents a discussion of a bus-controlled spectrum shaper that, in conjunction with a computer controlled realtime analyzer, allows the shape of the desired spectrum to be achieved without operator intervention. Uses for vibration excitation will also be discussed.

No abstract