In recent years the prediction and control of far field noise immission from live open air events has become a serious topic. Gaining permission and licensing to stage such productions often requires an official statement, predicting how the noise will impact on surrounding areas. The introduction of the far field noise immission modeling software, d&b NoizCalc, addresses this issue.
According to d&b audiotechnik, this new software tool takes the company’s promise of predictable, precise performance another step further. And before anyone asks what is “immission” - one of those ugly words which has entered the audio industry’s technical jargon - it’s important to explain that the term was adopted to differentiate between the sound propagated by a certain system (emitted) and the sound that is actually captured, affecting an area or addressed audience - the ‘immission’. The term is often used to differentiate between pollution (noise or otherwise) “emitted” (measured at the source) and effectively affecting a certain area of the surrounding environment.
NoizCalc models the sound propagation of coherently emitting complex sources such as line arrays and subwoofer arrays from multiple stages in the regions outside of the audience listening area and applies the results onto a 3D terrain map. This PC based software predicts the calculated far field impact of a d&b loudspeaker setup in the open air, by applying the
ISO 9613-2 and Nord 2000 standards. Using meteorological and geographical data, NoizCalc details the environmental propagation and relative attenuation values towards the far field at a defined spectrum and level reference.
Ground characteristics can be set depending on the absorbency or reflectivity of surfaces, while areas with volume attenuating properties can be defined. Buildings can be included, and the maximum reflection order option adjusts how many reflections are calculated. Parameters for humidity, air pressure and temperature ensure that the correct air absorption figures are accounted. The ISO 9613-2 standard requires limited meteorological information and assumes a worst case scenario. The more sophisticated propagation model, Nord2000 enables a more precise handling of meteorological conditions allowing the user to model with prevailing wind information.
NoizCalc is the result of the collaborative efforts of d&b audiotechnik and noise consulting and software development experts SoundPLAN GmbH. SoundPLANnoise applies an extended range of accredited worldwide standards along comprehensive reporting tools to satisfy the need for an official noise immission statement. The next version the software is able to import d&b system setups from ArrayCalc.
Both NoizCalc and SoundPLANnoise import d&b ArrayCalc simulation software project files, including complex data describing the relationships between sources and their combined performance, allowing loudspeaker systems to be virtually situated and oriented within 3D terrain models for realistic prediction.
Explaining the project, Werner “Vier” Bayer, d&b Product Manager says: “Our collaboration with SoundPLAN comes at a time when noise immission is becoming a major consideration in the planning of outdoor events. This free d&b software will enable system designers to investigate how their setup will impact on the wider area by modeling immission patterns ahead of time. NoizCalc forms the basis for a common understanding between those who create emissions: the loudspeaker system designers and technicians and the environmental noise and immission specialists, who consider the impact on the wider ecology.“
Further information and video tutorials are available on the company’s website.
www.dbaudio.com
