Noise Reduction inside Plant and Building


Noise reduction at work areas inside production facilities is essential not only to conserve hearing of employee, but also help employee to accomplish work efficiently. In order to achieve low noise work areas in the enclosed space of a planned or existing facility, TOYO provides appropriate noise reduction methods for noise sources and the building.


Noise in the factory is economically reduced by means of a appropriate combination of the following:

  • Absorbing material,Partition, Screen, etc. for Building.
  • Acoustic hood, Acoustically lagging, Isolator, etc. for Noise sources.


The following two main effective noise reduction control can be provided, based on expertise and wide experience of noise control design for new plant and for the existing facilities,

1. Noise reduction design for building

  • determine whether absorbing materials need to be lined on inner walls and ceiling. If necessary the specification the location and extent of lining are defined considering noise propagation path reflected on the walls, ceiling, etc.
  • design sound insulating wall or partition with appropriate transmission loss, where noise through the wall is prevailing,

2. Noise reduction design for noise sources

  • determine whether noise reduction devices such as acoustic hood, acoustically lagging, silencer and so on need to be provided for noise source
  • specify acoustic performance of noise reduction devices
  • select the reduction methods from the view point of safety and operability Openings for access of employee, carry in/out of material and product and for ventilation are acoustically designed to prevent leakage of nose.

Prediction of sound field in the building should include multiple reflections from different surfaces, diffraction and transmission of screen in the building.
In order to deal with the above acoustical behavior, an well-known advanced computer program “RAYNOISE” is used. RAYNOISE is designed to simulate the sound field of any arbitrary enclosed space such as industrial indoors and theaters, based on hybrid algorithms, combining the mirror image source method and the ray tracing method.
(Note) RAYNOISE is a registered trademark of LMS Numerical technologies NV.

Example of Noise Reductions inside Protection Room

Client's Requirement

Noise levels inside the production room and control room of the factory, where crushers and pumps are installed, are required to be reduced to conserve hearing.

Example of Service

The following noise reduction methods are determined;

  • Acoustic enclosure on the crushers with appropriate silenced devices
  • Absorptive material on inner walls of the production room

The noise level in community is predicted where the recommended noise reduction methods are provided for major noise sources.

Benefits to Client

determine specification and extent of absorptive material on inner walls

reduce noise reflected on inner walls

determine performance of acoustic enclosure having carry in /out openings

High noise from crushers in the production room is reduced

determine appropriately transmission loss of a partition wall between the production room and control room

Noise level in the control room is reduced to satisfy with good vocal communication.

Example of Analysis

Noise level in each room are studies before and after noise reduction methods, simulating noise propagation by crushers and pumps. From the viewpoints of effectiveness and cost of noise reduction method, appropriate reduction methods are determined.