Project number: 4.S.02
Author name: Witold Mikulski
Title: Developing of a test stand for measuring ultrasonic noise with the use of a reference ultrasonic noise source
Key words: ultrasonic noise,  sound source, test stand, high sound power level

Description:
The task consisted in comparing several sound sources in view of developing a reference ultrasonic noise source. The analysis showed that the simplest solution for a source that would meet these assumptions was a source whose  element radiating acoustic energy was an electrodynamic transducer. A model and then a prototype of a ultrasonic sound source were produced.
Emission of the prototype of a ultrasonic sound source was measured to verify the assumptions. A test stand was also developed for measuring emission, propagation and emission of noise in the frequency band from 10 to 50 kHz.
Measuring the emission of ultrasonic noise of the prototype of the source involved defining the sound power level, the sound pressure level of the emission, defining the characteristics of directivity, defining changes in the time of emitted noise.
On the basis of the measurements of the directivity index, it was shown that the prototype of the ultrasonic noise source met the assumptions.

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Project number: 4.S.03
Author name: Emil Kozłowski
Title: Developing methods of assessing sound exposure experienced by professional musicians and the principles of reducing it
Key words: assessing sound exposure levels, reducing noise, professional musician

Description:
The task consisted in developing a method of assessing sound exposure levels experienced by professional musicians. This method was used to measure sound during rehearsals and a concert of a woodwind orchestra and rock and jazz bands. The obtained values of sound exposure level related to an 8-h work day during a concert and rehearsals of a woodwind orchestra showed that the admissible value was significantly exceeded.
The measurement of sound for rock music took place during concerts of five bands playing in a stadium. The sound exposure level related to an 8-h work day during rock concerts exceeded the admissible value for all musicians who took part in the measurements.
The measurement of sound for jazz music took place during a concert of three bands that played in a small club.  The sound exposure level related to an 8-h work day during rock concerts exceeded the admissible value for all musicians who took part in the measurements.
There were audiometric tests of the threshold of hearing after exposure to classic and rock music without earplugs and after they were used. Tests showed sound-induced hearing fatigue during concerts of classical or rock music. Repeated audiometric measurements showed full elimination - after 9-dB earplugs were used - of  hazard caused by exposure to sound in the case of classical music; 15-dB earplugs eliminated hearing fatigue caused by rock music.
The efficiency of sound screens for musicians was also tested. It was shown that a sound screen is an efficient solution for reducing exposure to the sound of the trumpet, flute, piccolo, oboe, violin and cymbal.
Principles of selecting and using earplugs by musicians were developed, as were guidelines, recommendations and information materials on reducing exposure to sound for professional musicians.

Application:
The results of the measurements can be used to increase the comfort of work for professional musicians

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Project number: 4.S.01
Author name: Bożena Smagowska
Title: Developing a method for assessing occupation risk related to exposure to noise of call centre operators
Key words: occupational risk assessment, exposure to noise, call centre operators, occupational safety

Description:
The aim of the task was to determine parameters characterizing noise at workstations of call centre operators, methods of measuring those parameters, methods of assessing occupation risk related to exposure to noise at those workstations and recommendations for controlling that risk.
Within this task, non-auditory effects on the body related to noise were analysed, the working environment of call centre operators was characterized and hazards related to annoying and harmful factors at the operatorsʼ workstations were discussed. Parameters characterizing noise, measurement methods and admissible values of the parameters were defined.
A procedure for measuring parameters that characterize noise at the workstations of call centre operators was developed. A preliminary version of a database with the results of measurement of noise at those workstations was also developed.
Preliminary measurements of noise parameters at 18 workstations of call centre operators were made; the telephone receiver was considered the source of noise.
The task also consisted in developing a testing procedure related to exposure to noise of call centre operators, which defined its scope, test methods, reference documents, place and conditions of using that procedure, measurement equipment, measurement uncertainty, measurement values and way of acting during the tests.

Application:
The results of the tests can be used in increasing work comfort of call centre operators.

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Project number: 2.R.18
Author name: Witold Mikulski
Title: Developing genetic algorithms for minimizing occupational risk related to exposure to noise in manufacturing enterprises
Key words: occupational risk, exposure to noise, genetic algorithm

Description:
The task consisted in proposing a method of minimizing occupational risk related to exposure to noise in the working environment with the use of genetic algorithms. It is based on acoustic models of the working environment. Software for simulation tests was developed. The functions of a genetic algorithm were implemented in it. A procedure for the simulations tests was developed, too. It was verified using as an example minimizing exposure to noise with the organizational method.
The software for simulation tests that was developed during the project was modified and further developed.  This included implementation of binary coding of floating point parameters in the genetic algorithm, the development of a user interface by adding elements of visualization of simulation tests and addition of scripts with parameters of models of the acoustic working environment that makes more effective use of the software possible .
To consider in the genetic algorithm limitations related to the location of noise sources and workstations, which can be present in the real working environment, the physical possibility to carry out the solutions obtained with the use of the genetic algorithm and to consider the cost of installing machines and the cost of rotating workers, the function of a penalty was introduced. It modifies adaptation so as to eliminate bad solutions.
Thus it was possible to formulate guidelines for designers of computer tools assisting in occupational safety and health management with respect to minimizing occupational risk related to exposure to noise.

Application:
The computer tools for verifying genetic algorithms, which were developed as part of this project, are functional programs, which can be used to assist in optimizing the location of noise sources and workstations and rotation of workers at their workstations to reduce occupational exposure to noise and resulting occupational risk.

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Project number: 4.S.07
Author name: Leszek Morzyński
Title: Developing a signal device supporting prevention of exposure of earmuff users to noise
Key words: earmuffs, admissible exposure to noise, signal device

Description:
The aim of the task was to develop a signal device supporting prevention of exposure of earmuff users to noise. The devices were developed for new models of earmuffs to alert their users about excessive exposure to noise resulting from an incorrect use or selection of earmuffs.
It was accepted that the developed device would signal exceeding exposure of
- 85 dB of A-level sound
- 115 dB of A-level sound,
- 135 dB of peak C-weighted sound pressure level.
Block diagrams of signal devices were  developed. Then electronic circuits were designed and produced, they function as the individual blocks of the model. The construction and the operation of those blocks were verified with simulation and laboratory tests. On that basis models of two versions of signal devices were designed and produced. They were calibrated and verified in laboratory conditions.
Different models of earmuffs with built-in signal device supporting prevention of exposure of earmuff users to noise were designed and produced.  The signal devices used in those models were based on miniaturized models.
A new kind of signal devices was also developed  - miniature portable signal devices that can be fitted inside any earmuffs to measure noise and to signal excessive exposure.
The models of earmuffs with built-in signal device supporting prevention of exposure of earmuff users to noise developed within the task, and the portable  signal devices were tested in real and laboratory conditions. Those tests concerned the operation of the signalling devices and their suitability for various types of noise.
A patent was submitted for the technical solution related to the fitting of the signal device supporting prevention of exposure of earmuff users to noise in the earmuff.

Application:
Results of experimental tests were used to develop guidelines for designers of earmuffs protecting against noise on the use of a signal device supporting prevention of exposure of earmuff users to noise in earmuffs.

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Project number: 4.S.05
Author name: Piotr Kowalski
Title: Assessing exposure to mechanical vibration in in-house transport workers with view of prevention
Key words: mechanical vibration, in-house transport, exposure assessment, prevention

Description:
The main aim of the task consisted in identifying the hazard of mechanical vibration in workers involved with in-house transport and indicating ways of reducing this hazard.  The main sources of exposure to mechanical vibration of in-house transport workers were identified. The main assemblies and subassemblies of machinery and equipment used in in-house transport were tested. Hand-arm and whole-body vibration were measured at selected 30 workstations of in-house transport operators. Vehicles and devices most commonly used in in-house transport were tested.
Additionally, admissible duration of exposure were determined for each workstation. Optimal results were listed in test cards that were developed within the task. The determined values of daily exposure at all the tested workstations were compared. They were also compared with the relevant admissible exposure in current regulations.
The assessment of exposure to mechanical vibration of in-house transport operators revealed that the assessed workstations could pose a great hazard to workers' health.  Vibrations were satisfactorily reduced only at one in 10 workstations; in other cases vibrations increased. This shows that assessing the seat or its incorrect selection by the manufacturer or user of a vehicle is not an efficient way of reducing vibrations.
A database with the results of the measurements at the workstations in in-house transport was developed. This makes it possible to introduce frequency characteristics of the measured signals.

Application:
The obtained test results constitute information and a tool (a database) that supports employers in meeting the requirements in the regulation of the minister of labour and social policy of November 29, 2002, and the regulation of the minister economy and industry of August 5, 2005, on selecting protective equipment and implementing  preventive activities to reduce personal exposure of in-house transport workers below the value of the maximal admissible intensity. They can also be used in designing protective equipment.

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Project number: 4.S.06
Author name: Leszek Morzyński
Title: Developing a dosimetric indicator for monitoring exposure to noise at workstations
Key words:  dosimetric indicator, workstation, exposure to noise

Description:
The task consisted in designing and producing a model of a dosimetric indicator for monitoring exposure to noise at workstations. An LED diode indicates exceeding any admissible value of noise.
Then, an information series (100 pcs) of dosimetric indicators for monitoring exposure to noise at workstations was designed and produced.  Developing the indicator involved construction work on miniaturizing the model indicator. At the same time necessary changes in the construction of the indicator were introduced.
The last stage of the task involved developing a modified version of the dosimetric indicator for monitoring exposure to noise at workstations; an information series (50 pcs) of the indicators was produced. Introducing changes in the electric construction of the indicator also resulted in changes that were introduced into the software of the indicator. It was also necessary to determine again the relationship between the value of sound pressure level and the output value form the analogue/digital microcontroller. Work resulted in a final version of the dosimetric indicator. This indicator is a portable device 76 x 58 x 19 mm (H x W x D), based on the MSP43oF2013 microcontroller, which processes measurement data and signals exceeding the value of the maximal admissible intensity.
The dosimetric indicators that were designed and produced in the second information series (50 pcs) were calibrated.

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Project number: 3.S.04
Author name: Witold Mikulski
Title: Developing procedures for determining the acoustic power level of technological sources of ultrasonic noise in an open space
Key words: acoustic power level, ultrasonic noise, procedures

Description:
The aim of the task was to develop procedures for determining the acoustic power level of technological sources of ultrasonic noise in an open space as well as to develop a test stand for determining the acoustic power level of sources of ultrasonic noise. Detailed conditions for using the basic method (a general procedure) for individual sources of ultrasonic noise were developed. They classify sources into 3 groups: sources that emit ultrasound noise at a defined level, sources that emit undefined ultrasound noise and sources that emit undefined impulse ultrasound noise. A test stand was also developed for measuring acoustic power level of sources of ultrasonic noise.
Also defined were methods of calculating (estimating) the effect of sound reflected form the walls of a laboratory, attenuating sound in the air as a function of the distance from the source and the influence of the measured emission of acoustic energy of other sources of ultrasonic noise on values of ultrasonic noise from the equipment studied.
On the basis of the method (the general procedure) measurement methods were developed: technical and approximate for determining acoustic power level of sources, including the level of acoustic power, averaged during acoustic power level and peak level of acoustic power, in the range of the frequency of ultrasonic noise.
The measurement procedures and the test stand were verified in laboratory conditions, in the field and in industrial conditions by doing testing a laboratory source of ultrasonic noise and typical technological sources of ultrasonic noise: ultrasonic welding machines, ultrasonic drilling machines, and ultrasonic launders. The results of measurements of acoustic power level of an ultrasonic launder  Intersonic type IS-4 were compared in laboratory conditions.

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Project number: 4.S.04
Author name: Anna Kaczmarska-Kozłowska
Title: Assessing  exposure to school noise and developing  principles of prevention
Key words: assessment of exposure, school noise, prevention

Description:
The aim of the task was to assess teachers' exposure to noise in primary schools (excluding music schools) and to develop principles of preventing exposure.  Assessment of teachers' exposure to noise and occupational risk assessment related to that exposure were conducted on the basis of the results of
- subjective tests in the form of  a questionnaire
- environmental tests, i.e., direct measurements in the working environment
- measuring the acoustic properties of school rooms (reverberation time and speech transmission index)
- analysis of data on hazards and occupational diseases registered at the level of the state (data from the Central Statistical Office and the Central Register of Occupational Diseases).
The analysis of the obtained results revealed that noise at teachers' workstations was the principal strenuous factor in their working environment.
Noise at school can be a strenuous factor in teachers' working environment; it can result in the development of occupational diseases (permanent hearing damage and chronic diseases of the vocal organ).
As the determined  levels of exposure to noise, related to the weekly work hours, at most teachers' workstations ranged within 66-78 dB and did not exceed the admissible values, the risk of an onset of permanent hearing damage is low. However, because of the high levels noise at schools (over 80 dB) - in corridors/halls during breaks and in gyms, it is not possible to exclude the risk of hearing damage.
Bad acoustic properties of classrooms in the schools that were studied (especially the long reverberation time in most classrooms, of the order of 0.8-1.7 s) increase the general level of noise in rooms.
The tests that were conducted indicate that it is necessary to take up noise prevention that includes technical and organizational prevention.
The staff room in a selected school underwent was adapted acoustically.

Application:
The obtained results can be used in activities aimed at increasing teachers' safety.

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Project number: 3.R.01
Author name: Jan Żera
Title: Studying the impact of the differences in combined characteristics of attenuation of hearing protectors on the efficiency of noise control.
Key words: noise control, hearing protectors, impulse noise

Description:
The aim of the project was to study combined characteristics of attenuation of hearing protectors (amplitude and phase characteristics) and to determine the impact of the differences in these characteristics on the properties of hearing protectors protecting against impulse noise and amplitude and phase characteristics of the hearing protectors as a function of frequency.
The project consisted in measurements of 22 earmuffs (Bilsom, Peltor, 3M, EAR, Opta and Frazer). Five subjects took part in those measurements. A measurement microphone was placed under the earmuffs worn by the subjects; MTW1 and MTW3 acoustic testers and KEMAR and Bruel&Kjaer acoustic manikins were used, too.
A Numberical model of a hearing protector was developed; its efficiency was tested. Numberical modelling was done with the measured amplitude and phase characteristics of earmuffs. The measurements were verified with audiometric measurements. This was done to determine to what degree the course of the measured amplitude and phase characteristics of earmuffs provide significant information on attenuating tonal components of noise.
The study showed that attenuating tonal components of noise with earmuffs can be quite different from the mean values measured as attenuating noise in accordance with the recommendations of standard EN 24869-1. At the same time the usefulness of modelling in assessing impulse noise was proven.

Application:
The test results can be a tool in estimating noise hazard and can help in improving working conditions.

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Project number: 2.R.14
Author name:  Bożena Smagowska
Title: Investigating the impact of ultrasonic noise on the perception of human doing work that requires concentration
Key words: ultrasound noise, psychomotor ability of human

Description:
The aim of the project was to determine the impact of ultrasonic noise annoyance on the perception and psychomotor ability of human doing work that requires concentration. A test stand was developed as part of this project; it makes it possible to test in laboratory conditions the impact of annoyance caused by ultrasonic noise on work that requires concentration; methodology was suggested. Acoustic sources of an ultrasonic signal were designed and produced for the test stand.
Subjects were selected on the basis of audiometric tests in low (125-800 Hz) and high (10-16 kHz) frequencies, the level of reactiveness (a temperament questionnaire) and health. Twenty males aged 20-30 years with average reactiveness, good hearing and good health qualified. Subjective tests showed that after exposure to maximum ultrasonic noise the number of subjects complaining of the following symptoms increased: pressure in the head, discomfort and nervous tension, sleepiness and problems with concentration.
The results of psychological tests and the questionnaire regarding subjective feelings vary; this may be caused by the learning experience in tests and by personal differences.

Application:
The results of the tests can be used in improving occupational safety.

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Project number: 2.R.15
Author name:  Piotr Kowalski
Title: A model of combine exposure to whole-body and hand-arm mechanical vibrations in the working environment
Key words: mechanical vibrations, working environment, risk assessment

Description:
The main aim of the project was to develop a model of a comprehensive assessment of workers' exposure to simultaneous whole-body and hand-arm mechanical vibrations. A methodology of investigating whole-body and hand-arm vibrations present at the same time in the working environment was developed within this project. It is based on simultaneous recording of acceleration signals  of hand-arm and whole-body vibrations. A methodology of studying the reaction of a worker's body to whole-body and hand-arm vibrations was also developed. Field studies were prepared at selected real workstations (based on the registration of signals of whole-body and hand-arm vibrations) and laboratory tests at special test stands for determining the reaction of the subject to various combinations of vibrations. Considering maximum admissible intensities and the requirements of Standard PN-EN ISO 13090, the kind of simulation exciting vibration signals was determined as well as the value and duration of exposure. Criteria for selecting subjects were developed as were the characteristics of the   vibrotactile perception threshold tests; after consultations they were accepted as basic tests. A laboratory test stand was developed for testing whole-body vibrations; it makes it possible to simulate exposure to vibrations acting on a sitting person. A test was also developed for testing exposure to hand-arm vibrations.
The test results confirmed that using the proposed method of assessing simultaneous exposure to hand-arm and whole-body vibrations, which is based on summing the energy (in the proposed model, doses proportional to the energy) at workstations where both types of vibrations are present is well-founded.

Application:
The developed model makes it possible to consider total exposure to simultaneous hand-arm and whole-body vibrations on the basis of signals of hand-arm and whole-body vibrations registered in accordance with standardized measurement methods in standards PN-EN 14253 and PN-EN ISO 5349.

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Project number: 3.R.10
Author name: Piotr Kowalski
Title: Using a neural network in assessing the efficiency of personal protective equipment protecting against local vibration
Key words: Neural networks, personal protective equipment,  hand-arm vibrations

Description:
The aim of the project was to develop a method of determining personal exposure to hand-arm  vibration of workers after using protective equipment.   Neural networks have been used to develop an algorithm for calculating personal exposure after protective equipment.
Software was developed, which makes it possible to model parameters of equipment protecting against hand-arm vibration with neural networks. Preliminary tests involved using the newly developed software. Parameters of an artificial neural network that imitated protective equipment protecting against hand-arm vibration were changed in simulated calculations.  
The next stage of the project involved developing a methodology of transmitting vibration by protective equipment protecting against mechanical vibration from real hand tools. Three operators took part in the tests. During typical operations with selected hand tools that represented the source of hand-arm vibration of various kinds. The test results were used to teach neural networks, which were used to model the behaviour of the tested anti-vibration gloves. The process of teaching the neural network was preceded with the new software being used to prepare a set of files with sample test signals.
The relative error between the squared sums of the samples in the buffer zone of the signal measured on the adapter inside the glove and produced at the output of the neural network that was the model of a glove was used as a measure of the quality of the process of teaching .

Application:
The test results make it possible to determine in greater detail the exposure to vibration and better protection of workers thanks to an individual selection of efficient measures decreasing the negative effects of vibration.

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Project number: 3.S.02
Author name:  Jan Żera
Title: Evaluating the efficiency of hearing protectors in conditions with real impulse noise
Key words: hearing protectors, impulse noise

Description:
The aim of the task was to evaluate the efficiency of hearing protectors in reducing the effect of impulse noise on hearing in real conditions where impulse noise is present. Earmuffs, earplugs and double protection with both earplugs and earmuffs used at the same time were tested. The tests took place in many locations, in which there was impulse noise in a training ground. Impulse noise emitted by industrial sources of noise was also considered.
The results showed that in situations of extreme peak levels of acoustic pressure neither of the two hearing protectors nor double protection guaranteed protection that would decrease the peak C-weighted sound pressure level under the protector to a level below the level of the admissible value of 135 dB. In the case of double protection it is also necessary to select properly the earplugs and the earmuffs. Attenuation with double protection increases in the range from a few to about 15 dB for short impulses. In the case of longer impulses double protection might not result in increased attenuation.

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Project number: 3.S.03
Author name:  Rafał Młyński
Title: Developing a methodology of selecting hearing protectors for workers exposed to noise
Key words: hearing protectors, impulse noise, health hazard

Description:
The aim of the task was to develop a methodology of selecting hearing protectors for workers exposed to impulse noise.
The task consisted in developing a method of selecting hearing protectors for exposure to impulse noise on the basis of a model. This model used existing data from laboratory measurements. It makes it possible to Numberically determine attenuation of impulse noise with hearing protectors for impulses with defined amplitude and time characteristics.
Then a method of measuring impulse noise was developed; it makes it possible to classify impulse noise into categories that can be used in selecting hearing protectors. Preliminary measurements of impulse noise were made. Developing a method of measuring impulse noise involved creating a measurement system and developing a way of analysing measurement data and software for analysing the course of acoustic impulses. This software determines peak C-weighted sound pressure levels and the duration of an impulse.
The next stage involved measuring impulse noise produced by 52 sources of impulse noise. The sources were typical military ones and the measurements included three kinds of machine guns, a ballistic barrel, a fuse of a hand grenade, a 98-mm mortar, a 122-mm howitzer, 30-mm cannon, a hand grenade launcher, explosions of TNT, hexogen Hx and ANFO. A software package was also developed for selecting hearing protectors according to the conditions in which there is impulse noise. The package is meant for assessing the efficiency and selecting hearing protectors where there is a hazard of impulse noise. Data from laboratory measurements are used, as is classification of impulse noise. A database with over 80 records on earmuffs and over 30 earplugs was created for the package.

Application:
The results of the task can serve as a guidance in suitable selecting hearing protectors protecting against impulse noise.

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Project number: 4.S.08
Author name: Paweł  Górski
Title: Developing an adaptive acoustic road signal with a module for registering data on noise
Key words: acoustic road signal, registering noise

Description:
The aim of the task was to develop a technical solution that would make it possible to decrease the sound pressure level of the signal emitted at pedestrian crossings, which lets visually impaired people cross the street safely. The hearing of visually impaired people was analysed with special attention paid to identifying an acoustic signal masked with traffic noise. The requirements that had to be met by properly working audible signal devices were also analysed. This analysis showed that signal devices emit correctly selected signals as far as the information function is concerned; however, if the level of the acoustic background was low, it was possible to considerably reduce the level of emitted noise without losing the required information.
This was followed by the development of a module for adapting the sound pressure level of the emitted signal of the model of the audible road signal device and the principles for a module for registering data on noise. A modified version of the signal module was also designed and produced as well as a module for registering data on noise with software for the control system. Those modules were integrated into one model of an adaptive road signal device.
Technical documentation of an integrated adaptive acoustic road signal was also developed as part of this task.

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Project number: 4.S.09
Author name: Dariusz Pleban
Title: Predicting emission of noise by machinery and equipment on the basis of the global acoustic quality index
Key words: global acoustic quality index, emission of noise, machinery and equipment

Description:
The task consisted in defining the global acoustic quality index of machinery, which is the function of the following frequency indices:
- acoustic power,
- distance between the workstation and machinery,
- radiation directivity,
- impulse and impact noise,
- distribution of the noise spectrum.
Machinery is acoustically dangerous if the value of the global index is greater than 1. This means that the admissible value of acoustic quality will be exceeded at a workstation. Two alternative methods of determining the global acoustic quality index were also developed: a method that uses standardized methods of determining the sound power level and the inverse method.
Four series of experimental tests were carried out to verify the determination of the global acoustic quality index. As a result global indices were determined for four engine-generators. To determine the sound power level,  the inverse method was used with simultaneous 16-channel registration o data. Each of the generators was modelled with one omnidirectional substitute source. Modelling took place within the frequency range from 10 Hz to 12500 Hz.
Software for predicting emission of noise by machinery in industrial spaces was developed on the basis of the global acoustic quality index.
Optimization carried out in the developed software with the use of a genetic algorithm is aimed at minimizing the noise hazard at the workstation.

Application:
The results of tests should minimize the noise hazard at the workstation.

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Project number: 2.R.17
Author name: Leszek Morzyński
Title: Investigation of the use of neural networks in active noise control systems with nonlinear processes
Key words: neural networks, active noise reduction

Description:
The project consisted in carrying out simulation tests related to using neural networks of various structure and training algorithm in active noise control systems. New algorithms for training neural networks - QNBP, QNBPM and PYKQNBPM - were developed on the basis of the results of simulation tests and an analysis of strategies of control and identification of dynamical non-linear systems. The training algorithms were verified with simulation tests in MATLAB. A Numberical model of an active noise control system was developed with that aim in mind. In this model the primary path was non-linear. A new control unit/platform of an active noise control system was also developed on the basis of a floating point signal processor. This system was used to verify the developed training algorithms in laboratory conditions. Software was developed for the control system; Software consists of neural networks and training algorithms. The test stand was modified, too; an acoustic waveguide was its principal element. An additional module of the waveguide was developed and produced; it makes non-linear phenomena in the primary path possible.
The final stage of the project primarily consisted in testing the developed algorithms and comparing them with existing algorithms regarding their computational complexity
and effectiveness.

Application:
The results of the tests were the basis for the development of guidelines on using neural networks in active noise control systems depending on the structure and parameters of the network and considering non-linear phenomena.

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Project number: 1.R.19
Author name: Paweł Górski
Title: Modelling the acoustic parameters of workplaces that ensure speech intelligibility and perception of acoustic signals for people with a hearing dysfunction and for the blind.
Key words: workplace, acoustic parameters, people with a hearing dysfunction and the blind, perception of acoustic signals

Description:
The aim of the project was to determine the requirements regarding the acoustics of workplaces in the context of ensuring speech intelligibility and perception of acoustic signals for people with a hearing dysfunction and for the blind, and to develop recommendations to make meeting those requirements possible.
Within this project, a method was developed to determine the intelligibility of speech and orientation in space in people with a hearing or vision dysfunction. Models of workplaces with selected acoustic conditions were developed; they were validated. Simulations were conducted regarding the acoustics of workplaces to ensure speech intelligibility and perception of acoustic signals for people with a hearing dysfunction and for the blind. CARA software was used in modelling workplaces. On the basis of the studies a laboratory test stand was designed and developed for subjective tests of hearing directivity and speech intelligibility. The test stand was put in a laboratory; 5 acoustic adaptations were done to reproduce workplaces with various acoustic conditions.
On the basis of the results of the analysis, and the simulation and laboratory tests, a recommendation was developed on acoustic adaptation. Also developed were recommendations for designers of workplaces regarding meeting the requirements for ensuring speech intelligibility and perception of acoustic signals for people with a hearing dysfunction and for the blind.

Application:
Recommendations on acoustic adaptation were developed, as were recommendations for designers of workplaces regarding meeting the requirements for ensuring speech intelligibility and perception of acoustic signals for people with a hearing dysfunction and for the blind.

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Project number: 2.R.16
Author name: Dariusz Pleban
Title: Development of a model of a semi-active system of reducing mechanical vibrations at workstations
Key words: mechanical vibrations, working stations, research

Description:
The project involved an analysis of whole-body vibrations transmitted by technical devices to the human body in seat - human and platform - human systems. Principles of constructing a model of a semi-active system of reducing vibrations were formulated on the basis of an analysis of whole-body vibrations transmitted by technical devices to the human body at workstations, available solutions of dampers with controlled damping/rigidity and sample results of studies of vibrations at real workstations.  Matlab-Simulink was used to develop a simulation model of the system, to define its parameters and to implement a control algorithm.
Dampers with controlled rigidity were selected for the semi-active system of reducing vibrations in accordance with the construction principles.
The next stage of the project involved developing a field version of the real model of the semi-active system of reducing vibrations. The system was built in the form of a suspension of the seat of the driver/operator of a self-propelled machine. One of the tested magneto-rheological RD 1005-3 dampers of Lord Co. was used.
Simulation tests were conducted as part of the verification of the developed semi-active system of reducing vibrations; the complete system of activating data and controlling in real-time was also tested.

Application:
The usability of the developed model of the semi-active system of reducing vibrations was determined in real conditions on the basis of the results of verification tests and technical parameters, which will lead to an improvement of the working conditions.

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Project number: 2.S.01
Author name: Dariusz Pleban
Title: Ensuring integration of a notified body with European networks of occupational safety and health in order to comply with obligations related to participation in an obligatory system of assessing conformity of products
Key words: notified body, occupational safety and health, system of assessing conformity of products

Description:
The aim of the task was to ensure that the Institute complied with obligations related to participation in an obligatory system of assessing conformity of products through integration with European networks of occupational safety and health and through developing competence and improving the position of the Institute as a notified body on the domestic and international forums.
Within the task, the following activities took place:
- 3rd European Conference on Standardization, Testing and Certification "Safer Products for Competitive Workplaces" was organized,
- scientific conferences on testing and certification/conformity assessment were taken part in,
- 15th International Conference on Noise Control "Noise Control 2010" was organized,
- coordination work of notified bodies at the international level was taken part in, in areas in which the Institute is a notified body,
- work of expert groups in the structure of the European network of specialists in occupational safety and health EUROSHNET was taken part in.

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