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After 18 years of its implementation of the Environmental Noise Directive (END) (EU, 2002), trends between 2012 and 2017 suggest that the number of people exposed to levels of noise considered harmful to human health has not significantly been reduced. Achieving a reduction of the negative impacts of noise pollution is essential within the context of the EU Action Plan: 'Towards Zero Pollution for Air, Water and Soil'. This report provides the compilation of a questionnaire sent to EIONET intending to identify the political, contextual, environmental, economic and societal challenges that countries, regions and cities face when planning and implementing measures for reducing the negative impacts of noise. About 147 answers have been provided covering 23 countries: 16 from EU27 and 23 from EEA38. The answers reflect that the Environmental Noise Directive was an important milestone for integrating noise reduction into the political agenda. There are positive factors that facilitate the implementation of the noise reduction policies like the public opinion and awareness, technology, digitalisation or the governance. On the other site, some factors undermine the reduction of environmental noise like the size of the urban areas, overcrowding or the increased mobility demand. Financial limitation is considered the main obstacle. Regarding future opportunities and challenges, it is very often mentioned that the instruments are there but require the political will to implement them. In this context, the newly published zero-pollution action plan aims to achieve a 30 % reduction in the number of people chronically disturbed due to noise from transport by 2030. There are mixed feelings about the impact of this target, very often considered not realistic. ; OCP/EEA/ACC/18/001-ETC/ATNI

Lärm ist ein wichtiger Aspekt der Arbeitssicherheit und die Werkzeughersteller müssen darauf achten, dass die Produkte für Hochgeschwindigkeitszerspanung lärmarm sind und somit die Gesundheit des Maschinenbedieners gewährleisten. Bei der Rotation von PKD (Polykristalliner Diamant)-Planfräsern zur Bearbeitung von Aluminiumteilen im Leerlauf ist der Geräuschpegel sehr hoch und soll reduziert werden. Im Rahmen des von der Deutschen Forschungsgemeinschaft geförderten Forschungsprojektes wurden Lärmminderungsmaßnahmen an Planfräsern am Institut für Werkzeugmaschinen IfW an der Universität Stuttgart erforscht.
 
Noise is an important aspect of occupational safety and manufacturers of tools for high-speed cutting must ensure that the products they make are low-noise, thus ensuring the occupational safety of the machine operator. Especially during the idle rotation of PCD face milling cutters for machining aluminium parts, the noise level is very high and should be reduced. Noise reduction measures on face milling cutters were researched at the Institute for Machine Tools at the University of Stuttgart as part of the research project funded by the German Research Foundation.

This paper presents properties of chosen multichannel algorithms for speech enhancement in a noisy environment. These methods are suitable for hands-free communication in a car cabin. Criteria for evaluation of these systems are also presented. The criteria consider both the level of noise suppression and the level of speech distortion. The performance of multichannel algorithms is investigated for a mixed model of speech signals and car noise and for real signals recorded in a car.

With presentation of Jet fueled Aircraft in 1950s Engine Jet Noise danger. With the present rate of development of avionics and broad use of plane controlled business carriers it is normal that aggregate flight (common and military) is marginally to pass by more than 4%. In these flying machine, cutting edge innovations are being utilized where the utilization of plane motors is unpreventable. A wide range of motors are creating commotion which has negative effect on environment and additionally person. Albeit singular air ship has ended up calmer in the course of recent years yet flight frequencies have expanded. High fast supersonic air ships are likewise utilizing for military purposes. This paper concentrates on the audit of different strategies utilized in the past to lessen the plane commotion as likewise the future expected approach's henceforth the subject manages sources, reasons for clamor and its engendering with an answer for counteract. In spite of the fact that it is a tremendous field in flying division, this subject is talked about to sum things up.

Translated from Sovetskoe Gosudarstvo i Pravo, no. 3, 1978.

Noise, or unwanted sound, exposure has been shown to have a wide range of negative physical and psychological effects. Although situational context, sound characteristics, and individual expectation affect the experience of noise and its related outcomes, the personality trait of noise sensitivity also plays a critical role in assessing noise impacts. As the most widely used 21-item Noise Sensitivity Scale measure of sensitivity is often too long to administer in time-sensitive field settings, the authors conducted five studies to create and validate a shortened, field friendly version of the original, longer measure of noise sensitivity. The resulting five-item measure of noise sensitivity was shown to be internally consistent, temporally stable, highly correlated with the original measure, and predictive of noise-related outcomes such as attitudes toward specific noise, acceptability ratings of noise events, and motivations for visiting quiet locations. The applied value of the scale and implications for facilitating future research are discussed.

Denne Ph.D. afhandling omfatter fundamentale betragtninger omkring topologier, algoritmer, implementeringer, metoder etc., der kan indg˚a i næste generation af aktive kontrol systemer. Specifikt foresl˚as der en variant af feedforward kontrol refereret til som indesluttet feedforward aktiv kontrol forkortet IFFAK. I denne topologi indg˚ar et sæt reference sensorer, der er positioneret p˚a en overflade, der fuldt ud indeslutter de ønskede stille-zoner, hvori et sæt performance sensorer monitorerer den opn˚aede støjreduktion. Denne indesluttet-feedforward aktiv kontrol (IFFAK) topologi er indlejret i et mange-input-mange-output (MIMO) system, der omfatter b˚ade feedforward og feedback kontrol. Det totale system er refereret til som et hybrid MIMO indesluttetfeedforward FBS (HMIMOIFFFBS). Undersøgelsen af et komplekst multi-kanals aktiv støjreduktion (ASR) system med hybrid feedforward og feedback topologier er motiveret ud fra krav om høj aktiv støjdæmpning i ekstreme støjmiljøer, som f.eks. opleves ombord p˚a luftb˚arne militære platforme. Støjoptagelser erhvervet ombord p˚a s˚adanne fartøjer afslører lydtryk, der ofte overstiger 140 dB re. 20 μPa. Endvidere udviser disse støjsignaler store tidslige s˚avel som spatiale variationer. Naturlige begrænsninger i feedback baserede aktiv kontrol (AK) systemer som typisk anvendes i moderne ASR støjværn, hvor modstøjssignalet notorisk er forsinket i forhold til den primære forstyrrelse, sætter en øvre grænse for, hvor stor en aktiv dæmpning, der kan opn˚aes. S˚aledes, hersker der i krævende militære applikationer et krav om nye mere avancerede og effektive ASR løsninger. Den opn˚aelige ASR i et FFS er i stor udstrækning bestemt af kohærensen mellem sættet af reference sensorer og sættet af fejl- eller performance sensorer. S˚aledes omfatter denne afhandling en del kohærensundersøgelser baseret p˚a diffustfeltsm˚alinger i et støjkammer samt m˚alinger, der er foretaget i en CH-47D Chinook helikopter. Fra disse kohærensanalyser kan det konkluderes, at IFFAK systemet anvendt p˚a pilothjælme giver mulighed for ca. 25 dB støjreduktion ved 100 Hz faldende til ca. 10 dB dæmpning ved 900 Hz. Endvidere, er der ikke nogen umiddelbare tegn p˚a en mætning med stigende antal reference sensorer. S˚aledes vil et større antal reference sensor forventeligt kunne øge den øvre ASR frekvensgrænse for systemet, der bestemmes af den rumlige samplingstæthed. I hybridsystemet indg˚ar der b˚ade et kontinuerlig-tids FBS og et diskret-tids FBS. Disse vil bidrage med yderligere støjreduktion primært overfor bredb˚andet støj henholdsvis overfor periodiske signaler. Tidsforsinkelser udgør en anden bestemmende faktor for den opn˚aelige effekt i et FFS design, men specielt i et FBS design, eftersom fysiske systemer altid opererer kausalt. For at vurdere størrelsesordenen af det tidsforspring som hver reference sensor giver i forhold til hver fejlsensor i det foresl˚aede IFFAK system indføres en størrelse, der betegnes som den spatialt-vægtet middeltidsgevinst. Der eksisterer imidlertid et problem, n˚ar man forsøger at modellere et fysisk system med en endelig rummelig udstrækning og hvor der s˚aledes ikke er nogen indlysende input-output definition med et endeligt-element multi-kanals system. Som regel eksisterer der ikke nogen unik overføringsfunktion eftersom systemet ikke bliver punktvist stimuleret, men derimod stimuleret xii over et areal som for eksempel under diffustfelts belysning. En ny akustisk signalbehandlingsmetode, der betegnes som samlet kanal residual spektral analyse (SKRSA) er udviklet. Denne metode benyttes til ekstraktion af fælles signal information fra forskellige observationspunkter i rummet. Ideen er at separere hvert spektrum i et kohærent spektrum og et residual spektrum. Indholdet i det kohærente spektrum kan opn˚aes som en linear kombination af spektrene fra de andre kanaler, hvorimod indholdet af det residuale spektrum er unikt for den p˚agældende kanal. I et specifikt eksempel, belyses et system best˚aende af et sæt reference sensorer monteret p˚a en Gentex HGU-55/P hjælm, der igen er p˚amonteret en hoved og torso simulator med et diffust lydfelt. Under anvendelse af SKRSA metoden estimeres den spatialt-vægtet middeltidsgevinst til at være i størrelsesorden 800-900μs. Afhandlingen omfatter ogs˚a en detaljeret beskrivelse af en ny id´e til en beregningsmæssig effektiv implementering af et multi-kanals system, hvor b˚ade de adaptive filtre, der indg˚ar i den aktive kontrol s˚avel som de adaptive filtre, der indg˚ar til modellering af systemoverføringsfunktionerne kan antage individuelle længder. En ny og mere generel variant af APA algoritmen er udviklet. Denne adaptive filter algoritme inkluderer parametre for b˚ade wægt-styret og kontrol-effekt-styret lækage, adaptiv tap-vægte regulering s˚avel som numerisk regulering og betegnes MC-αγΠ-APA. En simplificering af denne algoritme, fører til MC-αγΠ-NLMS algoritmen, der er en udbygget variant af NLMS algoritmen. Systemets evne til off-line simultant at kunne identificere et complex system best˚aende af ialt 28 enkelt systemgrene bliver demonstreret. Forskellig adaptive filtre samt parametering heraf bliver udforsket. Et nyt og generelt multi-hastigheds systemkoncept for aktiv kontrol er udviklet. Specifikt implementeres og testes et system, hvor der i alt samples med tre forskellige hastigheder. P˚a multi-hastighedsniveau 0 benyttes en meget høj samplingsfrekvens med henblik p˚a at reducere forsinkelser i konverteringstrinene, der indg˚ar i de sekundære grene. Den ikke adaptive kontrol udføres p˚a det lavere multi-hastigheds niveau 1. Herved tilsikres et kompromis imellem forsinkelser til afgivelse af modstøjssignaler og krav til en endelig system b˚andbredde. Sluttelig foreg˚ar den adaptive kontrol ved det lavere multi-hastigheds niveau 2. Herved begrænses den ofte beregningsmæssige tunge adaptive filter opdatering til en s˚a lav samplingsfrekvens som muligt. I et specifikt eksempel demonstreres, at en beregningsmæssig besparelse p˚a ca. 40% kan opn˚as under opretholdelse af samme ASR ved nedsampling fra multi-hastighedsniveau 1 p˚a 24 kHz til multi-hastighedsniveau 2 p˚a 3 kHz. Det er en almindelig ingeniørpraksis at foretage en antagelse om Gaussisk fordelte signaler. Imidlertid, er mange fænomener i dagligdagen bedst modelleret med s˚akaldte alfa-stabile fordelings funktioner. Dette gælder ogs˚a for støjsignaler, der ønskes undertrykt ved hjælp af et aktivt støjdæmpningssystem. Afhandlingen indholder en kort teknisk beskrivelse af de stabile fordelingsfunktioner samt adaptive filter algoritmer for disse type signaler. Store dele af HMIMOIFFFB systemet samt de udviklede metoder og algoritmer er implementeret i et realtids miljø, der inkluderer en signal processor. I første omgang vil disse blive aftestet p˚a en til form˚alet designet aktive kontrol testenhed. ; This Ph.D. thesis includes fundamental considerations about topologies, algorithms, implementations, methods etc., that can enter in the next generation of active control (AC) systems. Specifically, a new variant of feedforward control referred to as confined feedforward active control (CFFAC) is proposed. This topology is constituted from a set of reference sensors that are positioned on a surface that completely confines the desired zones of quite. A set of performance sensors monitors the achieved noise reduction. This CFFAC topology in turn is embedded in a multiple-input and multiple-output (MIMO) system that facilitates both feedforward and feedback control. The general system is then referred to as hybrid MIMO confined-feedforward feedback (HMIMOCFFFB) active noise reduction (ANR) system. The investigation of a multi-channel ANR system with hybrid feedforward and feedback topologies is motivated by requirements of high ANR attenuation in extreme noise environments as typically experienced onboard airborne military platforms. Noise recordings acquired on such platforms reveal very high sound pressure levels often exceeding 140 dB re. 20 μPa. Moreover, these noise signals exhibit large temporal as well as spatial variations. Inherent limitations are related to the use of stand-alone feedback AC implementation commonly applied in modern ANR headset. In such systems the anti-noise signal is notoriously behind the primary disturbance in time. Accordingly, in demanding military applications requirements on more advanced and effective ANR system designs prevail. The achievable ANR performance in a feedforward system (FFS) is to a large extent determined by the degree of coherence between the set of reference sensors and the set of error sensors (or performance sensors). Accordingly, this thesis includes a number of coherence analysis that are based on diffuse sound field measurements in a reverberant chamber and measurements conducted onboard a CH-47D Chinook helicopter. From these coherence analysis it can be concluded that the CFFAC system with 10 reference sensors applied to pilot helmets potentially provides approximately 25 dB noise reduction at 100 Hz decreasing to approximately 10 dB attenuation at 900 Hz. Moreover, there is no apparent sign of saturation of the noise reduction with an increasing number of reference sensors. Accordingly, by using more reference sensors the spatial sampling rate is increased which in turn most likely also will lead to an increased ANR bandwidth. The hybrid system is also constituted from a continuous-time feedback system (FBS) and a discrete-time FBS. The continuous-time FBS is primarily responsible for additional broadband noise reduction, whereas the discrete-time FBS primarily is responsible for the attenuation of periodic signals. Owing to the requirement on causal operation of a physical AC system time delays will also to a large extent determine the achievable performance in FFS design and in particular in FBS design. A quantity referred to as the spatially-weighted-averaged acquisition lead time is introduced to represent the averaged time-advance obtained by each reference sensor relative to each performance sensor involved in the proposed CFFAC system. A problem exist when one attempts to model a physical spatially distributed system with no obvious input and output channel definition by a finite lumped-elements multi-channel system. Usually, no unique transfer function x exist as the system is not point-wise excited, but excited over an area as in the case of diffuse sound field illumination. A new method for acoustical signal processing that is referred to as joint-channel residual spectral analysis (JCRSA) is developed. The JCRSA method is used for the extraction of joint signal information from different observation positions in space. The idea is to separate each spectrum in a coherent spectrum and a residual spectrum. The contents of the coherent spectrum can be obtained from a linear superposition of the other signals, whereas the residual spectrum bears information that is unique to each specific channel. In a specific example a system consisting of 10 reference sensors flush-mounted on a Gentex HGU-55/P helmet that in turn is mounted on a head and torso simulator (HATS), is exposed to diffuse sound field illumination. By applying the JCRSA method the spatially-weighted-averaged acquisition lead times provided by the reference sensors relative to the performance sensors are estimated to be as much as 800-900μs. The thesis also includes a detailed description of a new idea for a computational efficient implementation of a multi-channel system in which the adaptive filters for adaptive control as well as the adaptive filters used for plant modeling are allowing to take different lengths. A new and more general variant of the affine projection algorithm has been developed. This adaptive filter algorithm that is denoted by multiple-channel-αγΠ-affine projection algorithm includes parameters for both weight-driven and control-effort-driven leakage, adaptive tap-weight regularization as well as numerical regularization. A simplification of this algorithm leads to the MC-αγΠ-NLMS algorithm that is an extended variant of the NLMS algorithm. Off-line simultaneous system identification capabilities of a complex system involving a total 4 secondary paths, 20 feedback paths and 4 control-performance paths is demonstrated. Different adaptive filters and parameterizations hereof are examined. A novel and general multi-rate adaptive filter for adaptive AC has been developed. Specifically, a system involving 3 different sampling rates has been implemented and the results hereof are presented. In this multi-rate system conversion take place at highly oversampled rates in order to reduce the delays in the secondary paths. The non-adaptive control is performed at a somewhat lower rate. Hereby, a compromise between delays related to the generation of the anti-noise signal and the computational load involved is ensured. Finally, the adaptive control that might be computational intensive takes place at an even slower sampling rate hereby relaxing the requirements on a high bandwidth. It is demonstrated that computational savings as high as 40% can be achieved in a 192, 24, 3 kHz triple-rate system as compared with a 24 kHz single-rate system without sacrificing the ANR performance. It is common engineering practice to apply an assumption of Gaussian distributed signals. However, many phenomena encountered in daily life fall into a generalization of the normal distribution that is referred to as α-stable distributions. Noise sources encountered in the domain of AC are sometimes best fitted to the family of α-stable distributions. This thesis includes a brief technical introduction to the stable distributions and description of the adaptive filter that can be used for AC. Large parts of the HMIMOCFFFB system including the developed methods and algorithms have been implemented in a real-time environment (RTE) that includes a signal processor. Test on the helmet system will continue and a dedicated reference test unit (RTU) for AC is currently being designed.

Intelligent Products and Systems. Technology theme - Final report. Ventä, Olli (ed.). VTT Publications 635, 239 - 263 ; During the last decade fundamental research on smart structures using intelligent materials has raised industrial interest. One of the most challenging application field is noise and vibration control. The strongly coupled phenomena vibration and noise limit the design of highly advanced and efficient lightweight structures. To face the challenge European Union has granted funding for the Integrated Project Intelligent Materials for Active Noise Reduction - InMAR as the key European Union funded project in the area of Intelligent Materials within the FP 6. VTT's main focuses in InMAR project are in - developing novel concepts for vibroacoustic properties of light weight composite materials - developing new large surface structural and acoustic sensor-actuator pairs for sound transmission control developing new local feedback control methods, especially for multi-channel active sound transmission loss control - implementing active sound profiling for car interior sound quality control - applying the developed materials, actuators and control methods in passive design, and in active systems in car sound package design and elevator wall sound transmission loss increase. The first realization of novel composite panel concept at VTT is a GFRP panel with striped core made of two different materials. The panel shows up to 10 dB better sound insulation compared to the reference (homogenous stiff core) panel. Two types of polymer material based actuator-sensor elements have been developed together with Panphonics Oy, one for active structural control and the other for active acoustic control of sound transmission loss of panel type structures. Development of multi-channel digitally adjustable analog control system is carried out for the active systems e.g. utilising large surface polymer actuators. The developed FPAA prototype controller contains an FPAA unit board and a microcontroller. The prototype controller system has been tested in active car sound package mock-up with large surface polymer actuator-sensor pair with up to 9 dB improvement in the target frequency band with broadband acoustic excitation. Local feedback control system gives possibilities to tune and increase the sound insulation of the sound package at selected frequencies giving flexibility for the sound insulation design of car sound packages and other panel like structures. ; During the last decade fundamental research on smart structures using intelligent materials has raised industrial interest. One of the most challenging application field is noise and vibration control. The strongly coupled phenomena vibration and noise limit the design of highly advanced and efficient lightweight structures. To face the challenge European Union has granted funding for the Integrated Project Intelligent Materials for Active Noise Reduction - InMAR as the key European Union funded project in the area of Intelligent Materials within the FP 6. VTT's main focuses in InMAR project are in - developing novel concepts for vibroacoustic properties of light weight composite materials - developing new large surface structural and acoustic sensor-actuator pairs for sound transmission control developing new local feedback control methods, especially for multi-channel active sound transmission loss control - implementing active sound profiling for car interior sound quality control - applying the developed materials, actuators and control methods in passive design, and in active systems in car sound package design and elevator wall sound transmission loss increase. The first realization of novel composite panel concept at VTT is a GFRP panel with striped core made of two different materials. The panel shows up to 10 dB better sound insulation compared to the reference (homogenous stiff core) panel. Two types of polymer material based actuator-sensor elements have been developed together with Panphonics Oy, one for active structural control and the other for active acoustic control of sound transmission loss of panel type structures. Development of multi-channel digitally adjustable analog control system is carried out for the active systems e.g. utilising large surface polymer actuators. The developed FPAA prototype controller contains an FPAA unit board and a microcontroller. The prototype controller system has been tested in active car sound package mock-up with large surface polymer actuator-sensor pair with up to 9 dB improvement in the target frequency band with broadband acoustic excitation. Local feedback control system gives possibilities to tune and increase the sound insulation of the sound package at selected frequencies giving flexibility for the sound insulation design of car sound packages and other panel like structures.