Noise measurement methods include the use of sound meters

Health and safety in the workplace are serious issues and noise pollution is just one of the things which need to be constantly monitored. This is done with the use of sound meters or sound level meters and is an essential part of protecting employees from the harmful effects of dangerous noise levels. 

Noise pollution is the disturbing or excessive noise that may harm the activity or balance of human or animal life. The source of most outdoor noise worldwide is mainly caused by machines and transportation systems, motor vehicles, aircraft, and trains. Outdoor noise is summarized by the word environmental noise. Poor urban planning may give rise to noise pollution, since side-by-side industrial and residential buildings can result in noise pollution in the residential areas.

Measuring procedures

There are two basic approaches to measuring noise in the workplace:

·         The exposure of each worker, worker type or worker representative may be measured. The noise dosimeter is the preferable instrument for this purpose.

·         Noise levels may be measured in various areas, creating a noise map for the determination of risk areas. In this case, a sound level meter would be used to take readings at regular points in a coordinate network.

What is a sound level meter?

A sound level meter is a basic tool in measuring sound. A sound level meter or sound meter is an instrument that measures sound pressure level, commonly used in noise pollution studies for the quantification of different kinds of noise, especially for industrial, environmental and aircraft noise. However, the reading from a sound level meter does not correlate well to human-perceived loudness, which is better measured by a loudness meter. The current international standard that specifies sound level meter functionality and performance is the IEC 61672-1:2013.

What is a sound meter composed of?

Instruments for noise measurement include sound level meters, noise dosimeters and auxiliary equipment. The basic instrument is the sound level meter, an electronic instrument consisting of a microphone, an amplifier, various filters, a squaring device, an exponential averager and a read-out calibrated in decibels (dB).  

Sound level meters are categorized by their precision, ranging from the most precise (type 0) to the least (type 3). Type 0 is usually used in the laboratory, type 1 is used for other precision sound level measurements, type 2 is the general purpose meter, and type 3, the survey meter, is not recommended for industrial use. 

Nowadays, sound meters are becoming increasingly small and easy to use, while at the same time their measurement possibilities are expanding. For measuring non-steady noise exposures, such as those that occur in intermittent or impulse noise environments, an integrating sound level meter is most convenient to use. 

These sound level meters can simultaneously measure the equivalent, peak and maximum sound levels, and calculate, log and store several values automatically. It is important to make sure that noise measuring instruments are always properly calibrated. This means checking the instrument’s calibration acoustically before and after each day’s use, as well as making electronic assessments at appropriate intervals.