Noise and Noise Control

Volume 2

Malcolm J. Crocker

• Publisher: CRC Press
• Year: 2018
• Print ISBN:
  9781315895895
• eBook ISBN:
  9781351091893
• Topic: Technology & Engineering
• Subtopic: Civil Engineering
• Index: Technology & Engineering

This book is written more for the practitioner than the casual reader. Although a high mathematical level is not needed, for much of the material some engineering knowledge is desirable. Noise control is not easy and there are no magic answers to problems. Careful study and patience are required to produce proficiency in the field of noise control.

Chapter 1
Principles and Methods of Noise Control

Malcolm J. Crocker

Table of Contents

1. I. Introduction
2. II. Systematic Approach to Noise Problems
3. III. Some Common Noise Reduction Techniques
   1. A. Source Approaches
   2. B. Path Approaches
   3. C. Receiver Approaches
   4. D. Amount of Noise Reduction Required
   5. E. Noise Reduction Solutions
4. IV. Reduction of Noise by Vibration Isolation
   1. A. Introduction
   2. B. Theory of Vibration Isolation
   3. C. Simple Design Procedure and Worked Example
   4. D. Improved Design Procedure
   5. E. Use of Inertia Blocks
   6. F. Other Problems in Isolator Design
   7. G. Characteristics of Isolators
   8. H. Examples of Machinery Noise Reduction
      1. 1. Vibration Isolation of a Book-Trimming Machine
      2. 2. Vibration Isolation of Air-Handling System
      3. 3. Vibration Isolation of a Nail-Making Machine
      4. 4. Vibration Isolation of a Typewriter
5. V. Noise Control by Use of Absorbing Materials
   1. A. Introduction
   2. B. Absorption Coefficient
   3. C. Average Absorption Coefficient and Reverberation Time
   4. D. Sound Fields in Rooms
   5. E. Critical Distance
   6. F. Installation of Absorbing Panels
6. VI. Noise Control by the Use of Enclosures and Barriers
   1. A. Introduction
   2. B. Definitions
   3. C. Sound Transmission
      1. 1. Mass Law
      2. 2. Double Panels
   4. D. Effects of Leaks
   5. E. Effects of Flanking Transmission
   6. F. Further Considerations
   7. G. Close-Fitting Enclosures
   8. H. Partial Enclosures
   9. I. Barriers
7. VII. Noise Control by Use of Damping Materials
   1. A. Introduction
   2. B. Measurements of Damping
      1. 1. Decay Method
      2. 2. Half-Power Point Method
      3. 3. Reverberation Time Method
      4. 4. Input Power Method
   3. C. Practical Considerations in Use of Damping Materials
8. References

I. Introduction

Each noise control problem is slightly different and should be treated on an individual basis. However, there are sufficient similarities between some problems that it is useful to approach noise problems in a systematic way. Bolt and Ingard¹ and Harris² have discussed such a systematic approach to noise problems before, and other authors have since, e.g., Beranek³ and others.^4,5,6 However, they were not the first. One can find references in the early literature to such a systems approach to noise problems more than 50 years ago,⁷ where at least the concepts of "path" and "receiver" were used. The systematic approach normally used is to consider each noise problem in the SOURCE-PATH-RECEIVER framework, and this is discussed in more detail in Section II.

In Section II, various methods which have been useful in dealing with many noise problems are reviewed. Section III.D discusses how to determine the amount of noise reduction which should be required in different noise problems. The remaining sections of this chapter discuss in more detail some of the PATH techniques which have been found most useful. Most of these PATH techniques make use of the fact that there are only a few mechanisms by which noise energy can be reduced along its transmission path: (1) spreading of energy with distance from the source, (2) deflection of energy (by reflection, refraction, or diffraction), and (3) absorption of energy.¹ When each PATH technique is discussed, it is explained which mechanism is principally involved.

Later chapters of Volume II will show how the principles described in Chapter 1 can be applied to a wide variety of noise problems, including those in buildings, machinery, transportation vehicles, and the community.

I...

Table of contents

• Cover
• Title
• Copyright
• PREFACE
• THE AUTHORS
• Contents
• Chapter 1 Principles and Methods of Noise Control
• Chapter 2 Transmission of Sound Through Structures
• Chapter 3 Noise Control in Heating and Ventilating Systems
• Chapter 4 Community Noise
• Chapter 5 Noise Control Laws, Regulations, and Standards
• Index