Industrial Noise Series

The following documents provide an overview of environmental, industrial and workplace sound and noise control, including baffle and silencer design.

Fundamentals of Environmental Sound

Audible spectrum
Audible spectrum.

Author

Elden F. Ray

Synopsis

The Fundamentals of Environmental Sound explains the basics of noise, including the audible spectrum and sound waves. It describes how sound is measured, including decibels, frequency and weighted sound levels, and the basics of silencers and noise control products.

Table of contents:

  • Sound Metrics
  • The Basics of Noise Control

The Fundamentals of Environmental Sound


Community and Environmental Noise

Histogram of power plant sound levels
Histogram of power plant sound levels.

Author

Elden F.Ray

Synopsis

Community and Environmental Noise covers the acceptability of noise in a community, provides an overview of sound level measurements used by regulatory agencies, describes the physical and psychological affect of noise on humans, and defines environmental sound descriptors.

Table of contents:

  • Environmental Noise
  • Community Reaction
  • Day-Night Sound Level
  • Tones and Infra-Sound
  • Regulatory Sound Levels
  • Environmental Sound Descriptors

Community and Environmental Noise


Near-Field Noise

Inlet, Exhaust or vent silencer arrangement showing criterion locations.
Inlet, Exhaust or vent silencer arrangement showing criterion locations. The connecting ducts or pipes on either side of the silencer can be very long.

Author

Elden F.Ray

Synopsis

Near-Field Noise defines near-field sound level and breakout noise and outlines the criteria and pitfalls that must be taken into consideration when designing silencing solutions for customers.

Table of contents:

  • Near Field Sound Level
  • Where is the Criterion?
  • Where and What is the Source of the Noise?

Near-Field Noise


Modeling Sound Propagation

Definition of sound fields
Definition of sound fields.

Author

Elden F. Ray

Synopsis

Modeling Sound Propagation examines the sound modeling that is typically performed for most industrial noise applications. This section of the Industrial Noise series focuses on two aspects of sound radiation: aerodynamic sources and structural radiation from surfaces (breakout noise).

Table of contents:

  • Sound Propagation
  • Sound Fields
  • Propagation Modeling of Sound
  • Modeling Sound Propagation

Modeling Sound Propagation


Room Acoustics and Noise Control

Author

Elden F. Ray

Synopsis

Room Acoustics and Noise Control describes the acoustics of an interior space and the transmission of noise from one space to another space, and demonstrates how room acoustics, room sound level and material absorption are calculated for the purpose of designing noise control solutions.

Table of contents:

  • Introduction
  • Room Acoustics
  • Material Sound Absorption
  • Noise Control

Room Acoustics and Noise Control


Fundamentals of Noise Control

Author

Elden F. Ray

Synopsis

Fundamentals of Noise Control presents methods for modeling and determining the necessary noise reduction to meet a criterion, design issues to consider when designing a noise control solution for a particular situation.

Table of contents:

  • Noise Path Modeling
  • Noise Reduction and Criteria
  • Sound from Openings
  • Sound from Structures
  • Transmission Loss
  • Noise Mitigation

Fundamentals of Noise Control


Absorptive Silencer Design

Normal attenuation versus frequency for parallel baffles
Normal attenuation versus frequency for parallel baffles.

Author

Elden F. Ray

Synopsis

Absorptive Silencer Design explains the basics of absorptive silencer design and the fundamental approach in the design of parallel baffle silencers.

Table of contents:

  • Introduction
  • Silencer Performance
  • Flow Resistance and Resistivity
  • Flow Velocity
  • Baffle Attenuation Example
  • Baffle Modeling and Analysis
  • Self Noise and Insertion Loss
  • Insertion Loss
  • Transmission Loss
  • Parametric Examples

Absorptive Silencer Design


Reactive Silencers

Analysis of a 3 Chamber Reactive Silencer
Analysis of a 3 Chamber Reactive Silencer

Author

Elden F. Ray

Synopsis

Reactive Silencers describes the challenges and needed measurements to successfully design a noise control solution for reciprocating engines.

Table of contents:

  • Introduction
  • Standard Silencers
  • Design Basics

Reactive Silencers


OSHA – Noise Exposure in the Workplace

Author

Elden F. Ray

Synopsis

OSHA – Noise Exposure in the Workplace provides an overview of United States regulations and regulatory agencies that govern employee exposure to high sound levels.

Table of contents:

  • OSHA
  • MSHA

OSHA – Noise Exposure in the Workplace