Noise abatement
The noise abatement is used to noise and includes all the measures the noise avoid or reduce its effect on the environment, especially to humans. The aim is to avoid damage to health caused by noise. Noise control measures focus on the sound level (especially the sound pressure level ), the duration of the effect, the pitch , the tonality and the impulsiveness .
approaches
The spatial approach to noise abatement distinguishes between:
- Measures at the noise source (trigger of noise) through noise avoidance or noise reduction (active measures)
- Measures at the noise sink (recipient of noise) through noise protection or noise remediation (passive measures)
When road traffic noise both types of noise abatement are exemplary to find: Flüsterbeläge act lärmvermindernd, noise barriers affect noise protective.
The technological approach to noise abatement distinguishes between:
- directly generated airborne sound (primary mechanisms) and
- indirectly generated airborne sound (secondary mechanisms)
Directly generated airborne sound occurs without the involvement of structure-borne sound ; z. B. in a jet engine. In the case of indirectly generated air-borne sound, structure-borne sound is initially generated in a structure by a force excitation. This propagates in the structure. Airborne sound is then emitted by vibrations on the surface of the structure.
In the case of directly generated airborne sound, the turbulence in the air must be kept low in order to reduce noise. It is particularly important to ensure that components are not subjected to turbulent flow; see aeroacoustics .
When indirectly generated airborne sound, z. B. in the case of resonances , can be started at different points. First of all, the force curve can be influenced in such a way that it excites as few natural frequencies of the component as possible . This is always the case when there are no steep force jumps or force peaks. Furthermore, the input impedance of the component can be increased, e.g. B. by increased mass at the force introduction point. Finally, the structure itself can be damped, e.g. B. by anti-drumming with heavy mats or sandwich sheets.
Action at the source
Measures at the noise source serve to avoid noise emissions . They are differentiated into
Behavioral measures
Ways noises to avoid or sound level to decrease are:
- Compliance with legal noise levels such as room volume
- Compliance with legal and cultural rest periods such as night rest , public holiday rest ( Sunday rest ) and afternoon rest
- Use of noise lights that indicate when the noise exceeds a certain sound level (for example in a school classroom)
Technical measures
A sound absorption can both sound attenuation and through sound insulation can be achieved.
There are options for sound blocking or shielding by housing , for example in a soundproof cabin or by erecting a noise barrier or a soundproof screen .
Against driving noise , speed restrictions should be taken into account to reduce tire-road noise and traffic-calmed areas should be set up. There is the option of using plain bearings instead of roller bearings . In addition, a reversal of vehicle antennas can be used to avoid whistling sounds ( Kármán vortex street ).
Road surfaces made of concrete or asphalt up to whispering are suitable for reducing the noise level (volume) and the impulsiveness of the sound, for example by removing stone pavement and joints in the road surface.
Measures on the transmission route
On the transmission path, the sound propagation should be hindered or optimized according to requirements.
One way of transmission is
- a room, closed or open, where noise development and perception coincide. This room can act like a resonance body and undesirably amplify, transform or reverberate sound.
- a sound bridge that transfers sound between rooms
- Room types
A distinction is made between open spaces and closed spaces .
The open space is both in populated areas - in residential areas e.g. B. the courtyard of a residential complex, traffic route or industrial site - as well as in the natural area .
In a closed room , smooth, parallel walls can act as resonance bodies. There are closed rooms in which there are many people and high sound levels are undesirable: e.g. B. Kindergarten, school classroom , lecture hall , dining room (cafeteria, canteen), library, workshop, station hall, prayer room, swimming pool.
In some rooms, however, high sound levels are expressly desired in order to create a certain atmosphere, for example in certain sports stadiums or sports halls.
- Sound bridges
Sound bridges are z. B. formed by load-bearing elements within buildings such as wooden beams or steel girders .
In fairways , sound generated by ship engines can affect adjacent buildings. A concert hall that is located directly on a body of water with shipping traffic must be constructed accordingly so that no unwanted ship noises are audible ( Elbphilharmonie ).
Social participation
The education of the population, those affected by noise, those who cause noise and the approval authorities with regard to the effects of noise (health education), causes and measures against noise affects the behavior of all those involved. This includes early participation, which already takes place during spatial planning and land use planning .
With the European Environmental Noise Directive, further participation formats were introduced:
- Creation of noise maps to inform the population and authorities
- Preparation of noise action plans , e.g. B. with citizen participation
The day against noise is the German version of the international noise awareness days organized by the German Society for Acoustics.
Here, those affected and those involved in noise abatement measures organize themselves in citizen forums and organizations that have specialized in noise abatement, e.g. B. interdisciplinary environmental associations and professional associations such as the German Society for Acoustics and the league against noise .
Actions in the media
In 2008 Rundfunk Berlin Brandenburg (rbb Kulturradio) produced the radio play Tsunami over Germany by Heiner Grenzland . It is a 24/7 live reporting with real and especially prominent presenters in northern Germany about an enigmatic storm cloud that draws a path of destruction through Germany and turns out to be an acoustic tsunami . H. an all-destructive, extreme high-pressure sound wave, created by the noise emissions from cars, airplanes and industrial plants. The reporting, which is geared towards sensation, transforms this threat into a media event and at the same time "unravels" it through what has become a symptomatic mechanism in the media age . In addition to the media-critical approach , the author and director Heiner Grenzland also sends a drastic signal with this fiction of an acoustic environmental catastrophe in order to "raise our awareness of the environmental and health-damaging consequences of the continuously increasing noise emissions and thereby the advantages of quiet and environmentally friendly electrical Recognize and appreciate engines. "(Heiner Grenzland)
References and comments
- ↑ rbb press archive
- ↑ z. B. Sabine Porn , Raiko Thal , Ullizell u. a.
- ↑ An invention of the author
- ↑ The radio play pays homage to the war of the worlds and is built similarly to it; Instead of the Martians, there is a deadly high-pressure sound wave, an acoustic tsunami, the uncanny threatening power and the story ends with an acoustic GAU (that is, the surface of the earth becomes uninhabitable, people live in underground sound bunkers, where any non-vital sound generation is prohibited.) Otherwise the events follow the same pattern.
- ↑ Volksbühne