Hearing loss or deafness due to excessive noise exposure.

Noise (sound) is a pressure wave in air.  As it moves away from its source the energy is spread over a rapidly growing sphere so it becomes much lower at any given point.  Putting a barrier in the way casts a "sound shadow" in the path, lowering the level further..

Noise is measured on a log scale multiplied by ten (that's why its called a deci (ten) bel scale). Every increase of 3 dB means the energy has doubled, an increase of 10 dB equals a ten fold increase, and twenty dB equals a one-hundred-fold increase.

We hear sound change in strength at only a fraction of the actual power of the noise. When we hear a noise as twice as loud as another noise, it is actually about ten times (10dB) as powerful.

Because the ear reacts differently to sounds of different frequencies a measuring scale called dBA has been developed to mimic the ears response.  This is the scale used for most noise control work.  

• Independent published studies have found a risk reduction.
• Safety and health experts believe there is a risk reduction.

Reducing noise at the source (e.g., leasing quieter tools), by moving the noise source further from workers, or by erecting an enclosure or barriers to the noise, will reduce noise exposure.  There is extensive research that reducing noise exposure reduced noise-induced hearing loss.  Whether the noise exposure is reduced enough to result in significant prevention of hearing loss depends on the site characteristics, and specific actions taken.  Some enclosures will be more effective than others.

Task-specific effects have not been characterized, but poor communication in general reduces productivity.

Controlled studies have found that even high noise levels may increase output in terms of numbers of tasks but errors are more likely to occur and quality is reduce.  Tasks involving concentration are more vulnerable to noise disruption than are routine tasks, and intermittent noise tends to be more disruptive than continuous noise. Poor performance may continue after intermittent noise has stopped.

Reduction of noise at the source reduces or eliminates the need for a hearing conservation program.

Overall site safety is enhanced by better communication.

Productivity is improved by better communication and reduced worker stress.

Construction tool noise source levels and the measured effect of distance and barriers can be found on eLCOSH

Noise Control: A Guide for Workers and Employers

• Independent published studies have found an increase in productivity.
• Manufacturers or vendors have reported an increase in productivity.
• Safety and health experts believe there is an increase in productivity.

Reduction of the quality of performance during and after noise exposure has been demonstrated in controlled studies which, while relatively old, are still valid. These studies are reported on page 6 of The Noise and hearing Conservation Manual.

Some noise reduction strategies, such as increasing the distance from a noise source to workers, require some planning but do not require any materials.  Other noise reduction strategies can be achieved using materials commonly accessible on a construction site such as plywood or foamboard enclosures.  Although they are available in the market, the lease or purchase of muffled or quieter tools and equipment, require advance planning.

Also use hearing protection personal protective equipment (PPE), such as plugs and muffs for when adequate noise reduction is not possible.