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1

Pursuing analytically the influence of hearing aid use on auditory perception in various acoustic situations

Szymański Piotr, Poremski Tomasz, Kostek Bożena

Vibrations in Physical Systems

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2022

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Vol. 33, nr 1

art. no. 2022107

EN

The paper presents the development of a method for assessing auditory perception and the effectiveness of applying hearing aids for hard-of-hearing people during short-term (up to 7 days) and longer-term (up to 3 months) use. The method consists of a survey based on the APHAB questionnaire. Additional criteria such as the degree of hearing loss, technological level of hearing aids used, as well as the user experience are taken into consideration. A web-based application is developed, allowing answering the survey questions from any computer with Internet access. The results of the benefit obtained from the use of hearing aids in various acoustic environments, taking into account the time of their use, are presented and compared to the earlier outcomes. The research results show that in the first period of use of hearing aids, speech perception improves, especially in noisy environments. The perception of unpleasant sounds also increases, which may lead to deterioration of hearing aid acceptance by their users.

2

Objective and Subjective Assessment of the Sound Attenuation Efficiency Obtained by Custom Moulded Earplugs with Various Acoustic Filters – a Preliminary Study0

Gołębiewski Roman, Wicher Andrzej, Kaczmarek-Klinowska Milena, Mirugalska-Handke Karina

Archives of Acoustics

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2022

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Vol. 47, No. 2

201--212

EN

Background: Hearing loss caused by excessive exposure to noise is one of the most common health risks for employees. One solution for noise reduction is the use of hearing protectors, which is a very effective method for protecting hearing from the workplace noise. In order to obtain better attenuation efficiency, custom moulded earplugs can be equipped with a suitable acoustic filter. The effectiveness of the hearing protectors’ attenuation is based on real measurement of hearing thresholds for normal hearing people with and without hearing protectors. However, this is a time consuming process, and the obtained values are characterised by quite large inter-individual variability. The optimal solution is to measure the attenuation characteristics based on the objective method (without the presence of the subject), the results of which will be in accordance with the results of subjective tests. Therefore, the main purpose of the research in this work was to measure the attenuation characteristics of the self-designed custom moulded earplugs with and without acoustic filters through the use of subjective and objective methods, and to compare the results in terms of the research methods. Methods: Measurements of the acoustic attenuation obtained by custom moulded earplugs with designed F1, F2, and F3 acoustic filters (internal diameters dF1 = 1:25 mm, dF2 = 0:85 mm, and dF3 = 0:45 mm), as well as full insert earplugs (without any acoustic filters) were carried out using two methods: objective and subjective. The objective measurements were carried out in an anechoic chamber. The artificial head (High-frequency Head and Torso Simulator Brüel & Kjær Type 5128) was located at a distance of 3 m, directly opposite the loudspeaker. The test signal in the measurements was pink noise – in the frequency range up to 12.5 kHz and the level 85, 90, and 95 dB. The hearing protectors with and without acoustic filters were mounted in the Head and Torso Simulator which was connected with Pulse System Brüel & Kjær. Five normal hearing subjects participated in the subjective measurements. A pink noise signal was used for one-third octave bands: 125, 250, 500, 1000, 2000, 4000, and 8000 Hz. The attenuation value was defined as the difference (in dB) between the hearing threshold of the test signal with a hearing protector and the hearing threshold determined without a hearing protector. Results: The results of the objective method proved that in addition to the significant impact of frequency on the attenuation values, the type of filter used in custom moulded earplugs also had a significant effect. In addition, the results of the objective method showed that in the whole frequency range the highest attenuation values are shown by the full earplugs, achieving slightly above 45 dB for frequency of 8 kHz. The attenuation values obtained from subjective measurements also confirmed that both the frequency and type of filter significantly affect the attenuation values of the tested hearing protectors. Conclusions: The results of this study did not confirm the hypothesis that the measurement method had no significant effect on the attenuation characteristics of self-designed custom moulded earplugs with different types of acoustic filters. The largest differences in attenuation values between the type of measurement methods occur for the low frequency band (250 Hz) and for higher frequencies (4000 Hz mainly). The change of the internal diameter of the F1 filter from 1.25 mm to 0.85 mm (F2 filter) did not significantly affect the attenuation characteristics.

3

Extended High Frequency Hearing Thresholds in Tinnitus Patients with Normal Hearing

Ristovska Lidija, Jachova Zora

Archives of Acoustics

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2022

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Vol. 47, No. 4

449--455

EN

The aim of the study was to compare the extended high-frequency (EHF) hearing thresholds (10–16 kHz) in tinnitus and non-tinnitus ears, in a group of 98 patients with unilateral tinnitus and normal hearing at standard audiometric frequencies, in a 0.125–8 kHz range. It was found that a total of 65 patients (66%) had a hearing loss (a threshold shift >20 dB HL) in the EHF range and the EHF hearing loss occurred more frequently in the tinnitus ear than in the non-tinnitus ear. The data also indicate that the EHF thresholds increased with the patient’s age and were in most patients higher in the tinnitus ear than in the non-tinnitus ear.

4

Spatial Hearing Questionnaire : Psychometric Properties of Turkish Version and Correlations with Hearing Skills

Çildir Bünyamin, Tokgoz-Yilmaz Suna, Sennaroğlu Gonca

Archives of Acoustics

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2021

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Vol. 46, No. 2

249--258

EN

Objective: Self-report questionnaire is informative to assess general hearing disability. The aims of this study were to investigate the reliability of Turkish version of spatial hearing questionnaire (SHQ) and to analyze the validity of the SHQ by the correlation with speech, spatial, and qualities of hearing questionnaire (SSQ) and Turkish matrix sentence test (TMST). Methods: The first part of the study was the psychometric properties of the SHQ with 192 participants (137 with normal hearing, 55 with hearing loss). In the second and main part of the study, we applied two questionnaires (SHQ and SSQ) and TMST to people other than those included in the first part of the study (88 participants with bilateral sensorineural hearing loss). We compared the results of these two questionnaires and the TMST with the speech discrimination (SD) scores. Results: Turkish spatial hearing questionnaire’s internal consistency was 0.94 and 0.97 for individuals with normal hearing and for individuals with hearing loss, respectively. Moderate, positive, statistically significant correlation was observed between the SHQ and SSQ (r = 0:606, p = 0:001 in individuals with hearing loss who do not wear any hearing aid, and r = 0:627, p = 0:001 in hearing aid users), and SHQ and SD (r = 0:561, p = 0:032 in hearing aid users). According to TMST, moderate, positive, statistically significant correlation was found between SSQ and adaptive TMST in individuals with hearing loss who do not wear any hearing aid (r = 0:330, p = 0:033 for S0N90 and r = 0:364, p = 0:018 for S0N270). Conclusions: Turkish SHQ is a valid and reliable questionnaire for assessing hearing functions. SHQ, SSQ, and TMST are clinically beneficial measuring tools in planning the process of hearing rehabilitation and follow-up.

5

Industrial Noise as a Source of Threat in the Field of Blasting Technology in Coal Mines

Mocek Piotr

New Trends in Production Engineering

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2020

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Vol. 3, Iss. 1

83--97

EN

The publication presents partial results of hearing screening tests conducted in 2019 among employees of 37 hard coal mines located in the Śląskie and Małopolskie voivodships. The tests were carried out in different cities of both voivodships using the Mobile Hearing Diagnosis Center, which parked near the selected mine and specialized hearing diagnostics points of the ACSłuchmed Sp. z o. o. from Lublin. At the diagnostic points, detailed total audiometry tests were conducted on people diagnosed with hearing disorders as part of screening tests. The obtained results allowed to identify branches and workplaces with the highest risk of noise hazard in mines. The presented publication shows the results of noise measurement during blasting works and the results of anonymous surveys conducted among employees of the Department of Blasting Technology of hard coal mines. The survey concerned the subjective feelings of employees regarding noise levels at the workplace and its impact on their well-being and state of health. In the publication summary, the author draws attention to the need to take measures to constantly control the noise level at the workplace and introduce solutions that will enable its reduction and allow for better protection of employees against its damaging consequences.

6

Influence of noise on children’s sense of hearing

Kaczorowski Adam, Komasa Maria

Vibrations in Physical Systems

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2019

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Vol. 30, nr 1

art. no. 2019124

EN

Children are at risk of developing hearing problems due to their exposure to high sound pressure levels for excessive amounts of time. The aim of this project was to establish the relationship between sound levels in the most hazardous fields and their effect on children’s sense of hearing. Measuring sound pressure levels in schools, analysing earphone and headphone usage and comparing them to audiometry results enabled basic dependencies to be found. Some of the examined children fall outside the safe exposure times to certain sound pressure levels (according to WHO directives). The results analysed in frequency bands show that there is a clear correlation between a shift in hearing threshold and intensity levels in music. Noise during lessons is not very high, but the noise during breaks and of bell rings can influence children’s’ hearing to a certain extent. Due to improper usage of earphones and headphones, the young people we examined may develop hearing loss at an early age.

7

Ubytek słuchu wśród górników kopalń węgla kamiennego

Mocek Piotr

Systemy Wspomagania w Inżynierii Produkcji

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2019

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Vol. 8, iss. 1

263--279

PL

Artykuł podejmuje problematykę utraty słuchu wśród górników kopalń węgla kamiennego. Opisuje zagrożenia związane z hałasem występujące w górniczym środowisku pracy. Przedstawia wyniki krótkich badań testowych identyfikujących zaburzenia słuchu wśród wybranej grupy pracowników kopalń. Próbuje ocenić słabe i mocne strony występującego w Polsce systemu diagnostyki słuchu. Przedstawia ciekawe wyniki badań ankietowych przeprowadzonych wśród górników z zakresu zagrożeń hałasem oraz zwraca uwagę na możliwość wprowadzenia innowacyjnych rozwiązań z zakresu diagnostyki i profilaktyki zaburzeń słuchu w polskich kopalniach.

EN

The article deals with the problem of hearing loss among miners of hard coal mines. Describes hazards related to noise occurring in the mining work environment. It presents the results of short test tests identifying hearing disorders among a selected group of mine employees. The article also tries to assess the weaknesses and strengths of the hearing diagnostics system in Poland. It presents interesting results of surveys conducted among miners in the field of noise hazards and draws attention to the possibility of introducing innovative solutions in the field of diagnostics and prevention of hearing disorders in Polish mines.

8

Hearing tester - mobile application for hearing loss screening

Krzyżek Krzysztof, Kłaczyński Maciej

Diagnostyka

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2019

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Vol. 20, No. 3

87--95

EN

The article presents results of the work on creation of an application for Android mobile devices to perform hearing screening using pure-tone air conduction audiometry. The application was created in accordance with the procedure defined in the ISO 8253-1: 2010 standard and is to serve the widest possible group of people in a domestic environment, using headphones included with mobile devices. The effectiveness of the application was verified by performing comparative hearing tests on a representative group of patients with different hearing status. Validation was performed using the Interacoustics AD629 clinical audiometer and procedures adopted in the standards. The results of the test comparison were satisfactory. The mean error of the hearing threshold tested using the mobile application, compared to the clinical audiometer was 5.2 dBHL. In addition, the hearing threshold curves for the mobile application are similar in shape to the hearing thresholds for the clinical audiometer and coincide with the auditory experiences of the patients.

PL

Artykuł przedstawia wyniki prac nad stworzeniem aplikacji na urządzenia mobilne z systemem Android w celu wykonania przesiewowych badań słuchu w zakresie progowej audiometrii tonalnej przy przewodnictwie powietrznym. Aplikacja została stworzona zgodnie z procedurą określoną w normie ISO 8253-1:2010 i ma służyć jak najszerszej grupie osób w domowych warunkach badań przy wykorzystaniu słuchawek dedykowanych urządzeniom mobilnym. Działanie aplikacji zostało zweryfikowane poprzez wykonanie porównawczych badań słuchu na reprezentatywnej grupie pacjentów o zróżnicowanym stanie słuchu. Walidację przeprowadzono przy użyciu audiometru klinicznego Interacoustics AD629 i procedur przyjętych w normach. Wyniki badań porównawczych okazały się zadowalające. Średni błąd zbadanego progu słyszenia przy pomocy aplikacji mobilnej, w porównaniu do badań przeprowadzonych przy pomocy audiometru klinicznego, wyniósł 5.2 dBHL. Dodatkowo, krzywe progu słyszenia dla aplikacji mobilnej są zbliżone w kształcie do krzywych progu słyszenia dla audiometru klinicznego i pokrywają się z wrażeniami słuchowymi pacjentów.

9

Psychoacoustic Characteristics of Tinnitus in Relation to Audiometric Profile

Ristovska Lidija, Jachova Zora, Stojcheska Vase

Archives of Acoustics

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2019

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Vol. 44, No. 3

419--428

EN

The aim of the study was to examine the relationship between tinnitus pitch and maximum heating loss, frequency range of hearing loss, and the edge frequency of the audiogram, as well as, to analyze tinnitus loudness at tinnitus frequency and normal hearing frequency. The study included 212 patients, aged between 21 to 75 years (mean age of 54.4 ± 13.5 years) with chronic subjective tinnitus and sensorineural hearing loss. For the statistical data analysis we used Chisquare test and Fisher’s exact test with level of significance p < 0.05. Tinnitus pitch corresponding to the frequency range of hearing loss, maximum hearing loss and the edge frequency was found in 70.8%, 37.3%, and 16.5% of the patients, respectively. The majority of patients had tinnitus pitch from 3000 to 8000 Hz corresponding to the range of hearing loss (p < 0.001). The mean tinnitus pitch was 3545 Hz ± 2482. The majority (66%) of patients had tinnitus loudness 4-7 dB SL. The mean sensation level at tinnitus frequency was 4.9 dB SL ± 1.9, and 13 dB SL ± 2.9 at normal heating frequency. Tinnitus pitch corresponded to the frequency range of hearing loss in majority of patients. There was no relationship between tinnitus pitch and the edge frequency of the audiogram. Loudness matching outside the tinnitus frequency showed higher sensation level than loudness matching at tinnitus frequency.

10

Evaluation of Noise Exposure and Hearing Threshold Levels Among Call Centre Operators

Pawlaczyk-Łuszczyńska Małgorzata, Zamojska-Daniszewska Małgorzata, Zaborowski Kamil, Dudarewicz Adam

Archives of Acoustics

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2019

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Vol. 44, No. 4

747--759

EN

The aim of this study was to evaluate the hearing status of call centre operators in relation to their noise exposure. Conventional pure-tone audiometry and extended high-frequency audiometry were performed in 49 workers, aged 22-47 years (mean ± SD: 32.0 ± 6.0 years), working in call centre from 1.0 to 16.5 years (mean ± SD: 4.7 ± 2.9 years). Questionnaire inquiry aimed at collecting personal data, the information on communication headset usage habits, self-assessment of hearing ability and identification of risk factors for noise-induced hearing loss were also carried out. Sound pressure levels generated by the communication headset were determined using the artificial ear technique specified in CSA Z107.56-13 (2013) standard. The background noise prevailing in offices was also measured according to PN-N-01307 (1994) and PN-EN ISO 9612 (2011). Personal daily noise exposure levels in call centre operators varied from 66 to 86 dB (10-90th percentile). About half of the study subjects had normal hearing in the standard frequencies (from 250 to 8000 Hz) in both ears, while only 27.1% in the extended high-frequencies (9-16 kHz). Moreover, both high-frequency and speech-frequency hearing losses were observed in less than 10% of audiograms, while the extended high-frequency threshold shift was noted in 37.1% of analysed ears. The hearing threshold levels of call centre operators in the frequency of 0.25-11.2 kHz were higher (worse) than the expected median values for equivalent (due to age and gender) highly screened population specified in ISO 7029 (2017). Furthermore, they were also higher than predicted for 500-4000 Hz according to ISO 1999 (2013) based on the results of noise exposure evaluation.

11

Estimate of the Percent Reduction of the Workers Hearing Loss by Doing a Training Intervention Based on BASNEF Pattern

Fallah Madvari Rohollah, Laal Fereydoon, Abbasi Milad, Monazzam Mohammad Reza, Fallah Madvari Alireza

Archives of Acoustics

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2019

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Vol. 44, No. 1

27--33

EN

If we want to provide the efficient training intervention to increase the duration of using heating protection devices (HPDs) by workers, we need a tool that can estimate the person’s hearing threshold taking into account noise exposure level, age, and work history, and compare them with audiometry to find out the percent reduction of workers hearing loss. First, the workers noise exposure level was determined according to ISO 9612, then 4000 Hz audiometry was done to find age and work history. On basis of ISO 1999 the hearing threshold was estimated and if the hearing protection device was not used continuously and correctly, the hearing protection device’s actual performance was reduced adjusted with person’s audiometry. After training intervention, the estimate was done again and was compared with the adjusted audiometry. According to ISO 1999 standard estimation results, the percent reduction of the workers hearing loss level was 6.48 dB in intervention group. This level remained unchanged in control group. The mean score of hearing threshold estimation (standard ISO 1999) was statistically more significant than mean score of hearing threshold (p-value ¡ 0.001). The results show not significant change in control group due to Lack of changing of noise exposure level. In regards to the results of hearing threshold estimation based on ISO 1999 and comparing with workers audiometry, it can be seen that BASNEF training intervention increases the duration of Rusing the HPDs and it could be effective in reducing hearing threshold related to noise.

12

Assessment of the Effectiveness of a Short-term Hearing Aid Use in Patients with Different Degrees of Hearing Loss

Poremski Tomasz, Szymański Piotr, Kostek Bożena

Archives of Acoustics

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2019

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Vol. 44, No. 4

719--729

EN

The study presents evaluating the effectiveness of the hearing aid fitting process in the short-term use (7 days). The evaluation method consists of a survey based on the APHAB (Abbreviated Profile of Hearing Aid Benefit) questionnaire. Additional criteria such as a degree of hearing loss, number of hours and days of hearing aid use as well as the user’s experience were also taken into consideration. The outcomes of the benefit obtained from the hearing aid use in various listening environments for 109 hearing aid users are presented, including a degree of their hearing loss. The research study results show that it is possible to obtain relevant and reliable information helpful in assessing the effectiveness of the short-term (7 days) hearing aid use. The overall percentage of subjects gaining a benefit when communicating in noise is the highest of all the analyzed and the lowest in the environment with reverberation. The statistical analysis performed confirms that in the listening environments in which conversation is held, a subjective indicator determined by averaging benefits for listening situations individually is statistically significant with respect to the degree of hearing loss. Statistically significant differences depending on the degree of hearing loss are also found separately for noisy as well as reverberant environments. However, it should be remembered that this study is limited to three types of hearing loss, i.e. mild, moderate and severe. The acceptance of unpleasant sounds gets the lowest rating. It has also been observed that in the initial period of hearing aid use, the perception of unpleasant sounds has a big influence on the evaluation of hearing improvement.

13

Influence of middle ear disorder in round-window stimulation using a finite element human ear model

Zhou Kai, Liu Houguang, Yang Jianhua, Zhao Yu, Rao Zhushi, Yang Shanguo

Acta of Bioengineering and Biomechanics

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2019

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Vol. 21, no. 1

3--12

EN

The aim of this work was to study the effect of middle ear disorder on round window (RW) stimulation, so as to provide references for the optimal design of RW stimulation type middle ear implants (MEIs). Methods: A human ear finite-element model was built by reverse engineering technique based on micro-computed tomography scanning images of human temporal bone, and was validated by three sets of comparisons with experimental data. Then, based on this model, typical disorders in otosclerosis and otitis media were simulated. Finally, their influences on the RW stimulation were analyzed by comparison of the displacements of the basilar membrane. Results: For the otosclerosis, the stapedial abnormal bone growth severely deteriorated the equivalent sound pressure of the RW stimulation at higher frequencies, while the hardening of ligaments and tendons prominently decreased the RW stimulation at lower frequencies. Besides, among the hardening of the studied tissues, the influence of the stapedial annular ligament’s hardening was much more significant. For the otitis media, the round window membrane (RWM)’s thickening mainly decreased the RW stimulation’s performance at lower frequencies. When the elastic modulus’ reduction of the RWM was considered at the same time especially for the acute otitis media, it would raise the lower-frequency performance of the RW stimulation. Conclusions: The influence of the middle ear disorder on the RW stimulation is considerable and variable, it should be considered during the design of the RW stimulation type MEIs.

14

Noise-induced hearing loss in bus and truck drivers in Mazandaran province, 2011

Alizadeh A., Etemadinezhad S., Yazdani Charati J., Mohamadiyan M.

International Journal of Occupational Safety and Ergonomics

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2016

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Vol. 22, No. 2

193--198

EN

Background and purpose. Noise-induced hearing loss (NIHL) is among the most prevalent and preventable work-related disorders. This study was conducted to evaluate the prevalence and severity of NIHL in bus and truck drivers of Mazandaran province in north Iran. Materials and methods. In a cross-sectional descriptive study, 2283 drivers were examined clinically and para-clinically, including measuring their fasting blood sugar, triglyceride and cholesterol levels. All participants were evaluated for the air and bone thresholds of both ears. Twenty-three individuals were excluded from the study because of conductive hearing loss. Data from 2260 drivers were analyzed using SPSS version 18. Results. Of the drivers, 37.5% had hearing loss in the right ear and 41.8% of the drivers had hearing loss in the left ear in one or more frequencies of sound. Hearing loss was significantly more frequent in the left ear and in 6000 Hz followed by 4000 Hz. Conclusion. Our study showed that the prevalence and severity of NIHL is high in drivers of Mazandaran province. There was a correlation between hearing loss and age and driving work history. We recommend considering hearing conservation programs more seriously.

15

Noise in the industry – threat for health

Irimia A., Găman G. A., Simion S., Călămar A., Pupăzan D.

Management Systems in Production Engineering

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2015

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nr 3 (19)

138--141

EN

The success of certain industrial activities bring both benefits and negative effects such as pollution, occupational diseases, exposure of workers and residents of neighboring areas and high risk in case of technological failure. An undesirable effect of industrial activity which may be considered a threat to workers and residents in the immediate vicinity of industrial sites is the noise. Due to the presence of technology in all activities, is a major problem considering its nature and harmful repercussions on health. Hearing loss and deafness caused by occupational exposure to noise at work are the most common occupational diseases that occur in the European Union. The development of modern technology by increasing the power and speed of the technical equipment, contributed to diversify and increase the number of sources of noise and vibration, and thus to increase the number of people exposed. This paper analyzes the effect of noise from industrial equipment and health risks.

PL

Sukces w działalności przemysłowych przynosi zarówno korzyści, jak i negatywne zjawiska, takie jak zanieczyszczenie, choroby zawodowe, ekspozycja pracowników bezpośrednich oraz sąsiedztwa zakładów przemysłowych na ryzyko związane z awariami, katastrofami technologicznymi. Niepożądanym efektem działalności przemysłowej, który może być uznany za zagrożenie dla pracowników oraz otoczenia zakładów jest hałas. Z uwagi na obecność technologii w większości działań, głównym problemem wynikającym z natury hałasu są jego negatywne skutki zdrowotne. Ubytek słuchu czy głuchota spowodowane ekspozycją na hałas w miejscu pracy są najczęściej występującymi chorobami zawodowymi w Unii Europejskiej. Rozwój nowoczesnej technologii poprzez wzrost wydajności i szybkości działania wyposażenia wpływa na dywersyfikację i wzrost liczby źródeł hałasu i wibracji a tym samym oddziałuje na większą liczbę osób. W artykule przedstawiono oddziaływanie hałasu pochodzącego z maszyn oraz zagrożenia zdrowotne.

16

Design and preliminary testing of the test apparatus to analyse the impact of hearing problems on the ability to repeat sound by singer

Kramarczyk M., Półrolniczak E.

Journal of Theoretical and Applied Computer Science

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2015

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Vol. 9, nr 3

3--8

EN

It is likely that serious hearing loss affect drastically human possibility of repeating the sounds. Remains the question of whether and how the delicate hearing loss affect the person’s ability to repeat sounds. Therefore we try to create the database samples singing, expanded on the tests of hearing for individual sigers, that could be used to further research in this direction. The studies were used two research stations one for the hearing test, and a second used to test the ability of the singer to repeat sound. First station used for hearing tests utilized a standard, certified audiometric cabin with cooperating with her professional audiometer. The second test station was design for record and analyse singers ability to repeat sound. Projected solution, use tools for both generate, playback and recording audio, with used adittional materials to improve the acoustic performance of the tests. This article describes the design of test aparature and presents the conclusions of the preeliminary tests, in particular those related to the second set of equipment.

17

Problematyka ochrony słuchu i oceny zagrożenia hałasem wytwarzanym przez broń palną

Młyński R., Kozłowski E.

Logistyka

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2014

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nr 5

1140--1146

PL

Hałas impulsowy wytwarzany podczas strzałów z broni palnej charakteryzuje się znacznie większymi wartościami szczytowego poziomu dźwięku C niż ma to miejsce w przypadku impulsów wytwarzanych w przemyśle np. podczas obróbki metalu. W zależności od rodzaju broni, wystrzałom towarzyszą impulsy o poziomie 160 - 177 dB, lub nawet wyższym. Należy przy tym zaznaczyć, że hałas impulsowy obecny podczas wystrzałów z broni palnej jest szczególnie niebezpieczny i w skrajnych przypadkach trwały ubytek słuchu może być wywołany nawet pojedynczym impulsem. Szczególnego znaczenia nabiera więc ocena narażenia na ten rodzaj hałasu i skuteczność jego ograniczania przez ochronniki słuchu. Wśród kryteriów oceny narażenia na hałas wyróżnić trzeba przepisy odnoszące się do stanowisk pracy i wojskowe kryteria ryzyka uszkodzenia słuchu. Proces oceny narażenia wiąże się z określonymi trudnościami pomiarowymi, takimi jak niedostateczny zakres pomiarowy standardowych mierników poziomu dźwięku i wynikająca z tego konieczność stosowania specjalizowanego systemu pomiarowego. Ochrona słuchu napotyka natomiast na problem braku kompatybilności używanego przez żołnierzy wyposażenia: np. hełmów i nauszników przeciwhałasowych.

EN

Impulsive noise produced by firearms is characterized by a much higher values of the C-weighted peak sound pressure level than in the case of impulses produced in the industry e.g. during metalworking processes. Depending on the type of weapons, shootings are associated with impulses which level is 160 - 177 dB or even higher. It should be noted that the impulse noise present during the firing of firearms is particularly hazardous and in extreme cases, permanent hearing loss can be caused by even a single impulse. Of particular importance is assessment of exposure to this kind of noise and the effectiveness of its limiting by hearing protectors. Among the criteria for the assessment of exposure to noise it should be listed regulations applied to workstations and hearing damage risk criteria developed for the Army. The process of assessment of exposure is associated with certain difficulties in measurements, such as insufficient range of standard sound level meters and consequently need for using specialized measurement system. Hearing conservation while encountering the problem of the lack of compatibility of equipment used by the soldiers, e.g. helmets and earmuffs.

18

Signal Recognition and Hearing Protectors With Normal and Impaired Hearing

Lazarus H.

International Journal of Occupational Safety and Ergonomics

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2005

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Vol. 11, No. 3

233--250

EN

Recognition of acoustic signals when perception is subject to interference from noise has already been extensively studied. In this study the influence of hearing protectors (HP) (plugs, muffs) and hearing loss on signal recognition is examined. Different spectrums and levels of the noise are also included. The test results are shown as the masked threshold for the signals heard and identified. In the case of normally hearing subjects a frequency-independent HP (plug) improves hearing performance, while frequency-dependent HP (muffs) tends to worsen it, especially with low-frequency noise. Hearing losses even worsen hearing performance when plugs are worn. Design suggestions are made to optimise signal recognition. Minimum signal-to-noise ratio and the use of HP are discussed.