EN 1793 Road Traffic Noise Reduction Devices - Determination of Acoustic Performance

The European standard “EN 1793 Road traffic noise reduction devices - Test method for determining acoustic performance” consists of the following sub-sections published under the same title:

• The standard “EN 1793-1 Part 1: Intrinsic properties of sound absorption under diffuse sound field conditions” describes a laboratory method for measuring the sound absorption performance of road traffic noise reduction devices under reverberant conditions. This standard covers the evaluation of the intrinsic sound absorption performance of devices that can reasonably be installed in the test facility described in EN ISO 354. This method is not designed for determining the intrinsic sound absorption properties of noise reduction devices to be installed on roads under anechoic conditions.

The test method described in EN ISO 354, referenced in this standard, excludes devices that behave as poorly damped resonators. Some devices deviate significantly from these requirements, and in these cases, caution should be exercised in interpreting the results.

When a sound-reflecting surface is laid along the road, using sound-absorbing devices on the traffic side can be effective in reducing additional noise disturbance from reflected sound. This may be necessary in the following situations:

• Noise barriers, rocks, or retaining walls can reflect sound waves away from unprotected areas.
• Vertically facing sections or reflective surfaces.
• Tunnels and tunnel approaches.
• Reflections between vehicles and the barrier, and traffic passing near the barrier, can reduce the barrier's effectiveness.
• EN 1793-2 Part 2: Intrinsic properties of airborne sound insulation under ubiquitous sound field conditions describes a laboratory method for measuring the airborne sound insulation performance of road traffic noise reduction devices under reverberation conditions. This standard covers the evaluation of the intrinsic performance of barriers that can reasonably be installed in the test facility described in EN ISO 10140-2 and EN ISO 10140-4.

This method is not designed to determine the intrinsic properties of airborne sound insulation for noise reduction devices to be installed on roads under anechoic conditions.

• EN 1793-3 Part 3: Normalized traffic noise spectrum describes a normalized traffic noise spectrum for evaluating and measuring the acoustic performance of devices designed to reduce traffic noise near roads.
• EN 1793-4 Part 4: Intrinsic properties - Intrinsic sound diffraction standard describes a test method for determining the intrinsic properties of sound diffraction of additional devices mounted on top of road traffic noise reduction devices. This test method involves measuring the sound pressure level at various reference points near the top edge of a road traffic noise reduction device, with and without the additional device mounted on top. The effectiveness of the additional device is calculated as the difference between the values ​​measured with and without the additional device mounted, correcting for height variation (the described method gives the acoustic benefit compared to a simple barrier of the same height, but in practice the additional device may increase the height, which may provide additional shielding depending on the source and receiver locations).

This standard applies to:

• Preliminary assessment for outdoor or indoor use of additional devices to be installed on road traffic noise reduction devices.
• Determining the difference in sound refractive index of additional devices in real-world use.
• Comparing design specifications with actual performance data after completion of construction work.
• Verification of the long-term performance of additional devices (by repeatedly applying the method).
• The interactive design process for new products, including the preparation of installation guides.

The test method can be applied both in situ and on samples specifically produced for testing using the method described here. Results are expressed as a function of frequency in one-third octave bands between 100 Hz and 5 kHz. If it is not possible to obtain valid measurement results across the entire specified frequency range, results are given within a limited frequency range, and the reasons for the limitation are clearly stated. A single numerical value is calculated from the frequency data.

• EN 1793-5 Part 5: Intrinsic properties - In situ values ​​of sound reflection under direct sound field conditions” standard describes a test method for measuring a quantity representing the intrinsic properties of sound reflection from road noise reduction devices, namely the reflection index.

This testing method is designed for the following applications:

• Determining the intrinsic characteristics of sound reflection from noise reduction devices to be installed on roads. These measurements can be taken at typical roadside installations or on a relevant sample cross-section.
• Determining the intrinsic characteristics of sound reflection in noise reduction devices in real-world use.
• Comparing design specifications with actual performance data after completion of construction work.
• Verification of the long-term performance of noise reduction devices (by repeated application of the method).

This test method is not designed to determine the intrinsic characteristics of sound reflection in noise reduction devices to be installed in reverberant conditions, such as inside tunnels or deep trenches. Results are expressed as a function of frequency in one-third octave bands between 100 Hz and 5 kHz. If it is not possible to obtain valid measurement results across the entire specified frequency range, results will be given within a limited frequency range, and the reasons for the limitation will be clearly stated.

• The standard EN 1793-6 Part 6: Intrinsic Properties - In-situ values ​​of airborne sound insulation under direct sound field conditions” describes a test method for measuring a quantity representing the intrinsic properties of airborne sound insulation for devices that reduce traffic noise: the sound insulation index.

This testing method is designed for the following applications:

• Measuring the intrinsic properties of airborne sound insulation for noise reduction devices to be installed on roads, either on-site or in laboratory conditions.
• On-site determination of the intrinsic properties of airborne sound insulation of noise reduction devices in actual use.
• Comparing design specifications with actual performance data after completion of construction work.
• Verification of the long-term performance of noise reduction devices (by repeated application of the method).
• The interactive design process for new products, including the preparation of installation guides.

This test method is not designed to determine the intrinsic properties of airborne sound insulation of noise reduction devices to be installed under reverberation conditions, e.g., inside tunnels, deep trenches, or under coverings. Results are expressed as a function of frequency in third-octave bands, as far as possible between 100 Hz and 5 kHz. If it is not possible to obtain valid measurement results across the entire specified frequency range, results will be given within a limited frequency range, and the reasons for the limitation will be clearly stated.

In short, the EN 1793 standards provide test methods for evaluating the acoustic performance of devices that reduce road traffic noise (commonly known as noise barriers, acoustic screens, or sound walls). These standards are considered important for the following reasons:

• It includes consistent and comparable measurement methods.
• It ensures reliable declaration of acoustic properties.
• It enables fair public procurement and CE marking.
• It enhances the effectiveness of real-world noise reduction.
• It supports compliance with legal regulations and public health.

For many years, our organization, with its competent and experienced staff, has been understanding the needs of its clients, providing the advanced testing services they require, and assisting them in the establishment, implementation, and improvement of management systems. Within this framework, we also provide testing services in accordance with the EN 1793 standard.