Pranab Saha is a well-known consultant and educator who has worked extensively with the automobile industry on real world vibration and acoustic related problems. This book relates that experience in a well-organized, easy to understand format. The book is well illustrated with an abundance of color figures to help explain the subject matter and concepts. This book is intended for entry level noise control engineers and the math is intentionally kept simple.
There is currently an acute need for noise control engineers due to large numbers of experienced engineers retiring. Consequently, engineers with little noise control experience are being pushed into noise control roles that they are ill prepared for. Presently, these engineers are acquiring expertise via commercial software and hardware training courses, seminars, and online courses. Though these learning mechanisms are helpful, a basic, yet applied, engineering text is needed. This book is well-suited to meet the needs of these engineers. Most vibration and acoustic texts are more mathematical and do not focus so heavily on applications. On the other hand, this book ably covers the basics with an eye on vehicle applications.
The first three chapters cover the needed basics that are generic to most applied acoustic texts. Chapter 1 covers fundamentals like the frequency domain, sound power, decibels, and weighting curves. Chapter 2 discusses how microphones, accelerometers, and laser vibrometers work and then proceeds to describe acoustic test facilities like reverberation and anechoic rooms. Chapter 3 surveys hearing metrics like loudness, sharpness, booming, roughness, and articulation index.
With those basics out of the way, Chap. 4 looks at the main sources of noise in internal combustion engine and electrical vehicles. Saha emphasizes source, path, and receiver mapping and informs the reader of the many structureborne and airborne paths in vehicles. Saha then describes how noise can be controlled at the source, path, and the receiver. Saha stresses that effective noise controls can only be implemented if the engineer understands the noise generating mechanisms, how noise propagates from the source to the receiver, and the various noise control methods and materials available.
Saha does an excellent job in describing how to apply the treatments while keeping the mathematics simple. For example, Chapter 5 describes how sound absorbers work and how they can be used to attenuate noise. The chapter explains that the sound absorption of porous absorbers is closely related to the particle velocity and the acoustic wavelength. Sound absorption metrics are described and qualitative effects of thickness, flow resistivity, and adding a mass layer are explained. The chapter concludes by considering Helmholtz resonators and perforated films or panels. In his explanations, Saha mainly presents equations without proof but then describes the equations conceptually. Chapters 6 and 7 are similar summaries of barrier and damper treatments.
In Chap. 8, Saha looks at several practical industry examples where sound absorptive, barrier, and damping treatments have been utilized and combined. These cases are like those encountered by engineers in industry and demonstrate how the principles in the prior seven chapters can be applied. This chapter should prove very valuable for noise control engineers.
Chapters 9 and 10 function like appendices. Chapter 9 details the test methods for measuring sound absorption, transmission loss, and vibration damping. The inclusion of this information is necessary and welcome. Chapter 10 covers additional topics like variation of the speed of sound with temperature and humidity, anechoic and reverberation room design, and test facility considerations.
In summary, Saha has done an excellent job in distilling the basics of noise control. Engineers who are starting to learn about noise control will value the book and more experienced readers can use the explanations and illustrations to explain concepts to colleagues. The book is clearly written and is uniquely geared towards bringing a novice up to speed. Explanations are kept brief and explanations are not dense. I suspect that entry level engineers will value the brevity since it provides enough content while not overwhelming them with too much information. Moreover, the technical discussions abet understanding and the layout is approachable rather than intimidating.