Canadian Centre for Occupational Health and Safety
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>Noise Control in Industry: A Basic Guide

Table of Contents



Section I

Why do we worry about noise

  1. Health effects: Auditory effects
  2. Health Effects: Non-Auditory Effects
    • Physiological Effects
    • Performance Effects
  3. Effect on Pregnancy


Section II

Basics of Noise

  1. What is noise?
  2. How do I know if I have noise problem in my workplace?
  3. Production and Transmission of Noise
  4. Units and Measures of Noise
    • Frequency
    • Sound Pressure
  5. Units and Measures of Workplace Noise
    • A-Weighted Noise Levels
    • Sound Pressure Level and Sound Energy
    • Continuous, Variable, Intermittent and Impulse Noise
  6. Sound Power
    • Relationship Between Sound Pressure Level and Sound Power Level


Section III

Measures of Workplace Noise

  1. Workplace Noise Level
  2. Noise Exposure Level of an Employee
  3. Relationship Between Noise Exposure Level and Noise Level Time Weighted Average (TWA) Noise
  4. Exposure Level
    • Comparison: TWA based on 3-dB and 5-dB exchange rates (rules)
  5. Evaluation of Noise Exposure Level


Section IV

Instruments and Methods of Measuring Noise

  1. Identifying Noise Problem
  2. Planning Noise Measurement
  3. Selecting Noise Measuring Instruments
    • Sound Level Meter
    • Integrating Sound Level Meter
    • Noise Dosimeter
    • Octave Band Analyzers
  4. Effects of Environmental Conditions on Noise Data
    • Correction for Background Noise
  5. Conducting Noise Measurements
    • Noise Survey
    • Measuring Equivalent Noise Using An Integrating Sound Level Meter
    • Noise Dosimetry
    • Measuring Impulse/Impact Noise
  6. Documenting Noise Levels Data


Section V

Evaluating the Risk of Noise-Induced Hearing Loss

  1. Types of Hearing Loss
    • Permanent Hearing Loss
    • Hearing Loss Due to Aging
    • Other Causes of Hearing Loss
  2. Measures of Hearing Loss
    • Hearing Disability
  3. Relationship Between Noise Exposure And Hearing Loss


Section VI

Occupational Noise Exposure Limits

  1. Noise Exposure Limits
    • Exposure Limits for Impulse/Impact Noise
    • Noise Exposure Limits for Extended Workshifts
    • Deciding Exposure Limits for Extended Workshifts
  2. Canadian and U.S. Noise Regulations
  3. Synergistic Effects: Ototoxic Chemicals
  4. Office Noise Levels


Section VII

Managing Workplace Noise Problems

  1. Hearing Conservation Program Components
  2. Noise Monitoring: Hazard Identification
  3. Noise Reduction: Engineering Controls
    • At the Source
    • Along the Path
  4. Hearing Protection
    • Advantages and Limitations of Earplugs and Earmuffs
    • Standards
  5. Hearing Measurement
  6. Administrative Controls
  7. Employee Training
  8. Program Evaluation and Continuous Improvement


Section VIII

Occupational Health and Safety Legislation

  1. Canadian Legislation
  2. What Does the OH & S Legislation Say
  3. Workplace Hazardous Material Information System WHMIS)
  4. U.S. Legislation


Section IX

Information Sources

  1. In Canada
  2. In the U.S.A..


Appendix A.

Sound Pressure Level Calculations

Definition of Decibel (dB)
Convert Dose to Equivalent Sound Level (Leq)


Appendix B.

Relevant Noise Standards

Canadian Standards Association
American National Standards Institute (ANSI).


Appendix C.

Further Reading


Appendix D.

Sound Absorbing and Sound Attenuation of Some Building Materials and Furnishings