Noise Monitoring and Controls
- Personal Noise Monitoring
- Area Noise Monitoring
- Noise Controls
- Community Noise Monitoring
Background Information on Noise-Induced Hearing Loss (NIHL)
Long term exposure to high noise levels results in noise-induced hearing loss. The damage to the hearing of a worker is permanent. The excess risk of hearing loss at different sound levels is provided in the following table.
Estimated Excess Risk of Hearing Impairment
as a Function of Average Daily Noise Exposure
|Average Daily Noise Exposure||Excess Risk of Hearing Loss|
|90 dBA||29 %|
|85 dBA||15 %|
|80 dBA||3 %|
Source: Occupational Noise Exposure, Revised Criteria 1998, NIOSH, pg. 20.
The Province of Manitoba has regulations and guidelines to prevent noise-induced hearing loss in the workplace. Employers are required to comply with the various requirements of the legislation. These requirements start as low as 80 decibels.
Personal Noise Monitoring
Provincial regulations require that noise testing include personal monitoring and be done a periodic basis. When performing personal noise monitoring, a small noise monitor is placed on the shoulder of a worker. As the worker goes about their normal duties, the noise level that the worker is exposed to, is recorded. The words are not recorded – just the noise levels, in decibels (dBA). At the end of the shift, the data can be downloaded. In addition to the average noise level that the worker was exposed to, a graph of the noise level is available.
Sample of Noise Level Graph Provided by Dosebadge Worn by Worker
A noise survey should also evaluate any hearing protection that the workers are wearing. The hearing protection for each worker is recorded and the effective exposure after allowing for their individual hearing protection is calculated.
Recommendations for Noise Controls
In some cases, noise levels can be dramatically reduced by the use of noise controls. This can be changes in the process, modifying tools, or acoustical insulation. Common sources of industrial noise include:
- Vibrating Surfaces
- Mechanical Impacts
- Gas flow: exhausts
- Air flow over surfaces
- Compression/rarefaction of medium example: blade passage of fan
In many cases, the one-time introduction of controls can reduce or eliminate the ongoing costs of industrial noise (audiometric testing, worker training, hearing protection).
For a free quotation please contact us.