Noise monitoring

What is noise? Noise is simply unwanted sounds. What people perceive as being noisy can vary greatly from person to person. Some have e.g. much greater tolerance than others. In addition, the experience of noise and especially the nuisance effects are not only dependent on the strength of the noise, but are also affected by objective factors. As some of the objective factors, one can highlight, for example, the nature of the noise and its variation over time. However, there are also subjective factors which can be linked in particular to the individual person's attitude towards the noise source, the possibility of control over the noise source, and the person's ability to deal with problems. It can, for example, be negative attitudes towards construction on neighboring land. Maybe you don't want the building to be built to begin with, or you are annoyed that they have blocked off a large area.

In order to protect people against noise, the Danish Environmental Agency has drawn up guidelines or binding noise limits for most types of external noise. The indicative limit values ​​are such that they correspond to a noise level where the most noise-sensitive (approx. 10%) indicate that they are strongly bothered by the noise. If the limit values ​​are observed, most people are not bothered by noise, and in terms of health it is considered to have no consequences.

Noise is measured with an approved sound pressure meter. We only perform measurements with approved type 1 microphones. Since the noise limits indicate the noise load during the day, evening and nighttime period, you cannot therefore simply hold a meter out the window and in that way conclude how noisy it is.

The noise is weighted in the daytime period (7-18) over the 8 noisiest hours, in the evening period (18-22) the noisiest hour, and the night period (22-7) the noisiest ½ hour. There may therefore be situations during the period that make more noise than the limit value, as long as the rest of the period is lower. The noise load is expressed as LAeq and can e.g. illustrated as seen in the picture.

For long-term monitoring, we use noise meters of the model S50, which are connected to a data logger model D10. The monitoring equipment is IP or in some cases IP68 approved. In this way, the equipment is protected against wind, weather and floods. For long-term projects, the equipment can be connected to 230 volts.

Contrary to the vibration meters, SMS alarms are not normally sent on the noise measurements. This is of course based on the fact that it requires a minimum of 8 hours during the day to see if a limit value has been exceeded. Therefore, daily or weekly reports are sent, depending on what the project requires, showing the noise load for the period. Most often, a noise plan has been drawn up beforehand, where the noise level has been shown through calculations. The monitoring is therefore often done as documentation that the calculations are also complied with, or as a result of complaints.

The noise meters can be connected to the same system as, for example, vibration meters, groundwater meters and dust meters. This way you can get all data delivered to the same place.