[Impact of infrasound and low frequency noise on human health and well-being. Part II: Review of epidemiological studies]. / Wplyw infradzwieków i halasu niskoczestotliwosciowego na zdrowie i samopoczucie czlowieka. Czesc II: przeglad badan epidemiologicznych.

This paper summarizes the currently available knowledge on the impact of infrasound (IS) and low frequency noise (LFN) on human health and well-being. This narrative review of the literature data was based on the selected, mostly, peer-reviewed research papers, review articles, and meta-analyses that were published in 1971-2022. It has been focused on the results of epidemiological studies concerning the annoyance related to infrasound and low frequency noise, as well as their impact on the cardiovascular system and sleep disorders. Particular attention was also paid to the latest research results and specific sources of IS and LFN, i.e., wind turbines. Med Pr Work Health Saf. 2023;74(5):409-23.

[Impact of infrasound and low frequency noise on human health and well-being. Part I: Review of experimental studies]. / Wplyw infradzwieków i halasu niskoczestotliwosciowego na zdrowie i samopoczucie czlowieka. Czesc I: przeglad badan eksperymentalnych.

This paper summarizes the currently available knowledge on the impact of infrasound and low frequency noise (LFN) on human health and well-being. This narrative review of the literature data was based on the selected, mostly, peer-reviewed research papers, review articles, and meta-analyses that were published in 1973-2022. It has been focused on infrasound perception, annoyance attributed to infrasound and low-frequency noise, as well as their effects on the cardiovascular system and sleep disorders. Particular attention was also paid to the latest research results and specific sources of infrasound and LFN, i.e., wind turbines. Med Pr Work Health Saf. 2023;74(4):317-32.

Reinvigorating engineered noise controls: a systems approach.

OBJECTIVES: Hearing loss is a major worldwide health issue affecting an estimated 1.5 billion people. Causes of hearing loss include genetics, chemicals, medications, lifestyle habits such as smoking, and noise. Noise is probably the largest contributing factor for hearing loss. Noise arises from the workplace, ambient environment, and leisure activities. The easiest noise sources to control are workplace and environmental. Workplace noise is unique in that the employer is responsible for the noise and the worker. Also, workers may be exposed to much higher levels of noise than they would accept elsewhere. Employers follow the traditional hierarchy of controls (substitution/engineering, administrative, personal protective equipment [PPE]). Substituting or engineering a lower noise level actually reduces the hazard present to the worker but demand more capital investment. Administrative and PPE controls can be effective, but enforcement and motivation are essential to reducing risk and there is still some hearing loss for a portion of the workers. The challenge is to estimate the costs more clearly for managers. A systems engineering approach can help visualize factors affecting hearing health. MATERIAL AND METHODS: In this study, a systems engineering causal loop diagram (CLD) was developed to aid in understanding factors and their interrelationships. The CLD was then modeled in VenSim. The model was informed from the authors' expertise in hearing health and exposure science. Also, a case study was used to test the model. The model can be used to inform decision-makers of holistic costs for noise control options, with potentially better hearing health outcomes for workers. RESULTS: The CLD and cost model demonstrated a 4.3 year payback period for the engineered noise control in the case study. CONCLUSIONS: Systems thinking using a CLD and cost model for occupational hearing health controls can aid organizational managers in applying resources to control risk. Int J Occup Med Environ Health. 2023;36(5):672-84.

Does Stochastic and Modulated Wind Turbine Infrasound Affect Human Mental Performance Compared to Steady Signals without Modulation? Results of a Pilot Study.

Wind turbines (WT) are a specific type of noise source, with unique characteristics, such as amplitude modulation (AM) and tonality, infrasonic and low frequency (LF) components. The present study investigates the influence of wind turbine infrasound and low frequency noise (LFN) on human well-being. In the between-subjects study design, 129 students performed a cognitive test evaluating attention and filled out questionnaires in three various exposure conditions, including background noise, synthesized LFN (reference noise) and registered WT infrasound (stimulus). No significant differences in test results or in the number of reported post-exposure feelings and ailments in various exposure conditions were found when analyzing them in males and females, separately. However, a significant association between pre-exposure well-being and reported post-exposure complaints was noted and explained by in-depth statistical analysis.

The adaptation of noise-induced temporary hearing threshold shift predictive models for modelling the public health policy.

OBJECTIVES: It has been shown that monitoring temporary threshold shift (TTS) after exposure to noise may have a predictive value for susceptibility of developing permanent noise-induced hearing loss. The aim of this study is to present the assumptions of the TTS predictive model after its verification in normal hearing subjects along with demonstrating the usage of this model for the purposes of public health policy. MATERIAL AND METHODS: The existing computational predictive TTS models were adapted and validated in a group of 18 bartenders exposed to noise at the workplace. The performance of adapted TTS predictive model was assessed by receiver operating characteristic (ROC) analysis. The demonstration example of the usage of this model for estimating the risk of TTS in general unscreened population after exposure to loud music in discotheque bars or music clubs is provided. RESULTS: The adapted TTS predictive model shows a satisfactory agreement in distributions of actual and predicted TTS values and good correlations between these values in examined bartenders measured at 4 kHz, and as a mean at speech frequencies (0.5-4 kHz). An optimal cut-off level for recognizing the TTS events, ca. 75% of young people (aged ca. 35 years) may experience TTS >5 dB, while <10% may exhibit TTS of 15-18 dB. CONCLUSIONS: The final TTS predictive model proposed in this study needs to be validated in larger groups of subjects exposed to noise. Actual prediction of TTS episodes in general populations may become a helpful tool in creating the hearing protection public health policy. Int J Occup Med Environ Health. 2023;36(1):125-38.

Noise exposure and hearing status among employees using communication headsets.

OBJECTIVES: The objective of this study was to assess the hearing of employees using communication headsets with regard to their exposure to noise. MATERIAL AND METHODS: The study group comprised 213 employees, including 21 workers of the furniture industry, 15 court transcribers and 177 call center operators, aged 19-55 years, working with headsets for a period of up to 25 years. All the participants underwent a standard puretone audiometry, extended high-frequency audiometry (EHFA) as well as transient-evoked otoacoustic emissions (TEOAEs) and distortion-product otoacoustic emissions (DPOAEs). Noise exposure from headsets was evaluated using the microphone in a real ear technique according to PN-EN ISO 11904-1:2008. RESULTS: Personal daily noise exposure levels ranged 57-96 dB and exceeded 85 dB only in 1.4% of the call center operators. Forty-two percent of the participants had bilateral normal hearing in the standard frequency range of 250-8000 Hz, and 33% in the extended highfrequency range of 9-16 kHz. It was found that DPOAEs were present bilaterally in 59% of the participants. Reproducibility of TEOAE at >70% and signal-to-noise ratio at >6 was exhibited by 42% and 17% of them, respectively. The 3 subgroups of workers differed in age, gender, noise exposure and type of headsets in use. However, after adjusting for age and gender, significant differences between these subgroups in terms of hearing were mostly visible in EHFA. A significant impact of age, gender, daily noise exposure level and current job tenure on hearing tests results was also noted among the call center operators and the transcribers. The most pronounced were the effects of age and gender, whereas the impact of the daily noise exposure level was less evident. CONCLUSIONS: It seems that EHFA is useful for recognizing early signs of noise-induced hearing loss among communication headset users. However, further studies are needed before any firm conclusions concerning the risk of hearing impairment due to the use of such devices can be drawn. Int J Occup Med Environ Health. 2022;35(5):585-614.

Hearing status of people occupationally exposed to ultrasonic noise.

OBJECTIVES: The aim of the study was to evaluate the hearing status of operators of low-frequency ultrasonic devices compared to employees exposed to audible noise at a similar A-weighted sound pressure level (SPL) but without ultrasonic components. MATERIAL AND METHODS: Standard pure-tone audiometry, extended high-frequency audiometry (EHFA), transient-evoked otoacoustic emissions (TEOAE), and distortion-product otoacoustic emissions (DPOAE), as well as questionnaire surveys were conducted among 148 subjects, aged 43.1±10.8 years, working as ultrasonic device operators for 18.7±10.6 years. Their exposure to noise within the ultrasonic and audible frequency range was also evaluated. The control group comprised 168 workers, adjusted according to gender, age (±2 years), tenure (±2 years), and the 8-hour daily noise exposure level (LEX,8h) of ±2 dB. RESULTS: The ultrasonic device operators and the control group were exposed to audible noise at LEX,8h of 80.8±3.9 dB and 79.1±3.4, respectively. The Polish maximum admissible intensity (MAI) values for audible noise were exceeded in 16.8% of the ultrasonic device operators, while 91.2% of them were exposed to ultrasonic noise at SPL>MAI values. There were no significant differences between the groups in terms of the hearing threshold levels (HTLs) up to 3 kHz, while the ultrasonic device operators exhibited significantly higher (worse) HTLs, as compared to the control group, in the range of 4-14 kHz. The results of the DPOAE and TEOAE testing also indicated worse hearing among the ultrasonic device operators. However, the differences between the groups were more pronounced in the case of EHFA and DPOAEs. CONCLUSIONS: The outcomes of all hearing tests consistently indicated worse hearing among the ultrasonic device operators as compared to the control group. Both EHFA and DPOAE seem to be useful tools for recognizing early signs of hearing loss among ultrasonic device operators. nt J Occup Med Environ Health. 2022;35(3):309-25.

[An assessment of exposure to noise and temporary changes in hearing related to working as a fitness instructor]. / Ocena narazenia na halas i czasowych zmian sluchu zwiazanych z praca na stanowisku instruktora fitness.

BACKGROUND: Music is for many people an integral part of their lives. In recent years, loud music, whether recorded or played live, has been a significant source of noise. The aim of the study was to assess the relationship between exposure to high sound levels and temporary threshold shift (TTS) in people working as fitness instructors. MATERIAL AND METHODS: The study included a total of 29 people (26 women and 3 men, age: 33±6 years) employed in 8 fitness clubs. The sound levels and the frequency characteristics of noise were assessed using individual dosimetry. Hearing threshold was evaluated by pre- and post-exposure pure tone audiometry (PTA), yielding a total of 116 audiograms. RESULTS: Occupational exposure of fitness instructors to noise lasted 60-120 min and the A-weighted sound pressure level (LAeq,T) in their workplace ranged 76.3-96.0 dBA (M = 87.1 dB). In 12% of individual measurements, the maximum admissible intensity (MAI) value for noise at the workplace was exceeded (MAI = 85 dB). In 41% of the surveyed instructors, a TTS of ≥6 dB at 4 kHz was observed. CONCLUSIONS: Fitness instructors may be a risk of hearing impairment related to their work. Med Pr. 2021;72(4):391-7.

Pure-Tone Hearing Thresholds and Otoacoustic Emissions in Students of Music Academies.

The objective of this study was to assess the hearing of music students in relation to their exposure to excessive sounds. A standard pure-tone audiometry, transient-evoked otoacoustic emissions (TEOAEs) and distortion-product otoacoustic emissions (DPOAEs) were determined in 163 students of music academies, aged 22.8 ± 2.6 years. A questionnaire survey and sound pressure level measurements during solo and group playing were also conducted. The control group comprised 67 subjects, mainly non-music students, aged 22.8 ± 3.3 years. Study subjects were exposed to sounds at the A-weighted weekly noise exposure level (LEX,w) from 75 to 106 dB. There were no significant differences in the hearing thresholds between groups in the frequency range of 4000-8000 Hz. However, music students compared to control group exhibited lower values of DPOAE amplitude (at 6000 and 7984 Hz) and signal-to-noise ratio (SNR) (at 984, 6000, and 7984 Hz) as well as SNR of TEOAE (in 1000 Hz band). A significant impact of noise exposure level, type of instrument, and gender on some parameters of measured otoacoustic emissions was observed. In particular, music students having LEX,w ≥ 84.9 dB, compared to those with LEX,w < 84.9 dB, achieved significantly lower DPOAE amplitude at 3984 Hz. Meanwhile, both TEOAE and DPOAE results indicated worse hearing in students playing percussion instruments vs. wind instruments, and wind instrument players vs. students playing stringed instruments.

Impact of very high-frequency sound and low-frequency ultrasound on people - the current state of the art.

For several decades, low-frequency ultrasound (<100 kHz) has been widely used in industry, medicine, commerce, military service and the home. The objective of the study was to present the current state of the art on the harmful effects of low-frequency airborne ultrasound on people, especially in occupational settings. The scientific literature search was performed using accessible medical and other databases (WOS, BCI, CCC, DRCI, DIIDW, KJD, MEDLINE, RSCI, SCIELO and ZOOREC), and the obtained results were then hand-searched to eliminate non-relevant papers. This review includes papers published in 1948-2018. The potential effects of the low-frequency airborne ultrasound have been classified as auditory and non-auditory effects, including subjective, physiological, and thermal effects. In particular, already in the 1960-1970s, it was demonstrated that ultrasonic exposure, when sufficiently intense, appeared to result in a syndrome involving nausea, headache, vomiting, disturbance of coordination, dizziness, and fatigue, and might cause a temporary or permanent hearing impairment. However, since that time, not too much work has been done. Further studies are needed before any firm conclusions can be drawn about the auditory and non-auditory effects of low-frequency airborne ultrasound. Int J Occup Med Environ Health. 2020;33(4):389-408.

[Evaluation of noise exposure and risk of hearing impairment in employees using communication headsets or headphones]. / Ocena narazenia na halas i ryzyko uszkodzenia sluchu u pracowników uzywajacych sluchawkowych zestawów komunikacyjnych lub sluchawek.

BACKGROUND: The aim of the study was to assess the noise exposure and risk of noise-induced hearing loss (NIHL) among users of communication headsets (CHs) or headphones. MATERIAL AND METHODS: Noise measurements and questionnaire surveys were carried out in 74 workers (aged: 31.8±7.3 years), including military aviation personnel (N = 12), transcribers (N = 18) and call center operators (N = 44). Sound pressure levels (SPLs) emitted by CHs (or headphones) were determined using the microphone in the real ear (MIRE) technique and artificial ear techniques according to PN-EN ISO 11904-1:2008 and CSA Z107.56-13, respectively. The risk of NIHL was evaluated in accordance with PN-ISO 1999:2000. RESULTS: The diffused-field-related A-weighted equivalent-continuous SPLs measured under CHs (or headphones) using the MIRE and artificial ear techniques reached values of 67-86 dB (10-90th percentile) and 68-89 dB (10-90th percentile), respectively. The study subjects used these devices 1.5-8 h (10-90th percentile) per day. Exposure to such noise levels for 40 years of employment causes the risk of hearing impairment (mean hearing threshold level for 2, 3 and 4 kHz > 25 dB) up to 10-12% (MIRE technique) or 19-22% (artificial ear technique). Individual daily noise exposure levels in study group varied 71-85 dB (10-90th percentile). A number of workers complained of problems with understanding speech in noisy environment (28.4%) and hearing whisper (16.2%) and experienced post-work temporary hearing symptoms (16.2-25.7%) as well. CONCLUSIONS: The users of CHs and headphones should be included in the hearing conservation program. Further studies are also needed among employees of other industries. Med Pr. 2019;70(1):27-52.

[Assessment of temporary hearing changes related to work as a bartender]. / Ocena czasowych zmian sluchu zwiazanych z praca na stanowisku barmana.

BACKGROUND: Noise in entertainment industry often reaches high sound pressure levels. Nevertheless, the risk of hearing loss in this sector is insufficiently recognized. The aim of this study was the assessment of the relationship between noise exposure and temporary threshold shifts (TTS) for people working as bartenders at a variety of entertainment venues. MATERIAL AND METHODS: The study comprised a total of 18 bartenders (mean age was 25±7 years old) employed at a music club (N = 8), pub (N = 5) and discotheque (N = 5). Personal dosimeters were used for determining noise levels and frequency characteristics. Hearing was evaluated by pre- (before work) and post-exposure (up to 15 min after the end of work) pure tone audiometry. Hearing tests were carried out for bartenders during 2 or 3 sessions while working on weekends. RESULTS: The mean personal noise exposure level normalized to a nominal 8-hour working day was 95 dBA, above 4 times higher than the accepted legal limit. The TTS values (10 dB HL or more) were significant at 4 kHz for both ears for 77% of bartenders. CONCLUSIONS: People working as bartenders represent a professional group with an increased risk of hearing loss. Raising awareness of this fact and implementing hearing protection programs in this group of workers is urgently needed, in line with the European Commission Directive (EU Directive 2003/10/EC). Med Pr. 2019;70(1):17-25.

[Evaluation of on-the-job noise exposure in the case of bartenders]. / Ocena narazenia na halas na stanowiskach pracy barmanów.

BACKGROUND: In places associated with the entertainment industry in which music is performed or played, sounds with high sound pressure levels may occur. Such exposure is a threat to both people spending their free time at concerts, in discos or pubs, as well as employees in these places. The aim of the research conducted in 2017 was to assess on-the-job noise exposure in the case of bartenders at various premises of the entertainment industry. MATERIAL AND METHODS: The measurements included 15 entertainment venues in Lódz, out of which 3 were selected: a music club, disco and pub. The exposure measurements were taken together for 4 work stations for bartenders using individual dosimetry in accordance with the PN-EN ISO 9612: 2011 standard. RESULTS: A total of 64 measurements were carried out, which showed that the equivalent sound levels A at the bartenders' workplaces vary considerably depending on the type of premises and the day of the week and the range of 67.6-108.7 dB. The highest sound levels occurred during the weekend (Fridays and Saturdays). The determined daily noise exposure levels exceeded the threshold of preventive action (80 dB) in 95% of the analyzed cases. Exceeding the maximum permissible noise level (NDN = 85 dB) was found in 66% of cases. CONCLUSIONS: It has been found that on-the-job noise levels in the case of bartenders significantly exceed the acceptable values of exposure levels and pose a risk of hearing damage. Med Pr 2018;69(6):633-641.

Noise exposure and hearing status among call center operators.

INTRODUCTION: The overall objective of the study was to assess noise exposure and audiometric hearing threshold levels (HTLs) in call center operators. MATERIALS AND METHODS: Standard pure-tone audiometry and extended high-frequency audiometry were performed in 78 participants, aged 19 to 44 years (mean ± standard deviation: 28.1 ± 6.3 years), employed up to 12 years (2.7 ± 2.9 years) at one call center. All participants were also inquired about their communication headset usage habits, hearing-related symptoms, and risk factors for noise-induced hearing loss (NIHL). Noise exposure under headsets was evaluated using the microphone in a real ear technique as specified by ISO 11904-1:2002. The background noise prevailing in offices was also measured according to ISO 9612:2009. RESULTS AND DISCUSSION: A personal daily noise exposure level calculated by combining headset and nonheadset work activities ranged from 68 to 79 dBA (74.7 ± 2.5 dBA). Majority (92.3%) of study participants had normal hearing in both ears (mean HTL in the frequency range of 0.25-8 kHz ≤20 dB HL). However, their HTLs in the frequency range of 0.25 to 8 kHz were worse than the expected median values for equivalent highly screened otologically normal population, whereas above 8 kHz were comparable (9-11.2 kHz) or better (12.5 kHz). High-frequency hearing loss (mean HTLs at 3, 4, and 6 kHz >20 dB HL) and speech-frequency hearing loss (mean HTLs at 0.5, 1, 2, and 4 kHz >20 dB HL) were noted in 8.3% and 6.4% of ears, respectively. High-frequency notches were found in 15.4% of analyzed audiograms. Moreover, some of call center operators reported hearing-related symptoms. CONCLUSIONS: Further studies are needed before firm conclusions concerning the risk of NIHL in this professional group can be drawn.

Response to Noise Emitted by Wind Farms in People Living in Nearby Areas.

The aim of this study was to evaluate the perception and annoyance of noise from wind turbines in populated areas of Poland. A questionnaire inquiry was carried out among 517 subjects, aged 18⁻88, living within 204⁻1726 m from the nearest wind turbine. For areas where respondents lived, A-weighted sound pressure levels (SPLs) were calculated as the sum of the contributions from the wind power plants in the specific area. It has been shown that the wind turbine noise at the calculated A-weighted SPL of 33⁻50 dB was perceived as annoying or highly annoying by 46% and 28% of respondents, respectively. Moreover, 34% and 18% of them said that they were annoyed or highly annoyed indoors, respectively. The perception of high annoyance was associated with the A-weighted sound pressure level or the distance from the nearest wind turbine, general attitude to wind farms, noise sensitivity and terrain shape (annoyance outdoors) or road-traffic intensity (annoyance indoors). About 48⁻66% of variance in noise annoyance rating might be explained by the aforesaid factors. It was estimated that at the distance of 1000 m the wind turbine noise might be perceived as highly annoying outdoors by 43% and 2% of people with negative and positive attitude towards wind turbines, respectively. There was no significant association between noise level (or distance) and various health and well-being aspects. However, all variables measuring health and well-being aspects, including stress symptoms, were positively associated with annoyance related to wind turbine noise.

Exposure to excessive sounds and hearing status in academic classical music students.

OBJECTIVES: The aim of this study was to assess hearing of music students in relation to their exposure to excessive sounds. MATERIAL AND METHODS: Standard pure-tone audiometry (PTA) was performed in 168 music students, aged 22.5±2.5 years. The control group included 67 subjects, non-music students and non-musicians, aged 22.8±3.3 years. Data on the study subjects' musical experience, instruments in use, time of weekly practice and additional risk factors for noise-induced hearing loss (NIHL) were identified by means of a questionnaire survey. Sound pressure levels produced by various groups of instruments during solo and group playing were also measured and analyzed. The music students' audiometric hearing threshold levels (HTLs) were compared with the theoretical predictions calculated according to the International Organization for Standardization standard ISO 1999:2013. RESULTS: It was estimated that the music students were exposed for 27.1±14.3 h/week to sounds at the A-weighted equivalent-continuous sound pressure level of 89.9±6.0 dB. There were no significant differences in HTLs between the music students and the control group in the frequency range of 4000-8000 Hz. Furthermore, in each group HTLs in the frequency range 1000-8000 Hz did not exceed 20 dB HL in 83% of the examined ears. Nevertheless, high frequency notched audiograms typical of the noise-induced hearing loss were found in 13.4% and 9% of the musicians and non-musicians, respectively. The odds ratio (OR) of notching in the music students increased significantly along with higher sound pressure levels (OR = 1.07, 95% confidence interval (CI): 1.014-1.13, p < 0.05). The students' HTLs were worse (higher) than those of a highly screened non-noise-exposed population. Moreover, their hearing loss was less severe than that expected from sound exposure for frequencies of 3000 Hz and 4000 Hz, and it was more severe in the case of frequency of 6000 Hz. CONCLUSIONS: The results confirm the need for further studies and development of a hearing conservation program for music students. Int J Occup Med Environ Health 2017;30(1):55-75.

[Do hearing threshold levels in workers of the furniture industry reflect their exposure to noise?]. / Czy progi sluchu u pracowników przemyslu meblarskiego wynikaja z ich narazenia na halas?

BACKGROUND: The aim of the study was to analyze the hearing status of employees of a furniture factory with respect to their exposure to noise and the presence of additional risk factors of noise-induced hearing loss (NIHL). MATERIAL AND METHODS: Noise measurements, questionnaire survey and assessment of hearing, using pure tone audiometry, were carried out in 50 male workers, aged 20-57 years, directly employed in the manufacture of furniture. The actual workers' hearing threshold levels (HTLs) were compared with the predictions calculated according to PN-ISO 1999:2000 based on age, gender and noise exposure. RESULTS: Workers under study were exposed to noise at daily noise exposure levels of 82.7-94.8 dB (mean: 90.9 dB) for a period of 3-14 years. In all subjects, mean HTL at 500 Hz, 1000 Hz, 2000 Hz and 4000 Hz did not exceed 25 dB. Nevertheless, high frequency notches were found in 11% of audiograms. The actual workers' HTLs at 3000-6000 Hz were similar to those predicted using PN-ISO 1999:2000. There were statistical significant differences between HTLs in subgroups of people with higher (> 78 mm Hg) and lower (≤ 78 mm Hg) diastolic blood pressure, smokers and non-smokers, and those working with organic solvents. Hearing loss was more evident in subjects affected by the additional risk factors specified above. CONCLUSIONS: The results confirm the need to consider, in addition to noise, also some other NIHL risk factors, such as tobacco smoking, elevated blood pressure, and co-exposure to organic solvents when estimating the risk of NIHL and developing the hearing conservation programs for workers. Med Pr 2016;67(3):337-351.

Exposure to excessive sounds during orchestra rehearsals and temporary hearing changes in hearing among musicians.

BACKGROUND: It has been shown that musicians are at risk of noise-induced hearing loss. The aim of the study has been to evaluate the temporary changes of hearing in the case of orchestral musicians after group rehearsals. MATERIAL AND METHODS: The study group comprised 18 orchestral musicians, aged 30-58 years old (mean: 40 years old) having 12-40 years (mean: 22 years) of professional experience. The temporary changes in hearing after group rehearsals were determined using transient-evoked otoacoustic emissions (TEOAEs). Noise exposures during group rehearsals were also evaluated. RESULTS: Musicians' hearing threshold levels were higher (worse) than expected for the equivalent non-noise-exposed population. Moreover, the high frequency notched audiograms were observed in some of them. After rehearsals, during which musicians were exposed to orchestral noise at A-weighted equivalent-continuous sound pressure level (normalized to 8-h working day) varied from 75.6-83.1 dB (mean: 79.4 dB). The significant post-exposure reductions of TEOAE amplitudes (approx. 0.7 dB) both for the total response and frequency bands of 2000 and 3000 Hz were noted. However, there were no significant differences between pre- and postexposure reproducibility of TEOAE. CONCLUSIONS: Obtained results have confirmed that orchestral musicians are at risk of hearing loss due to their professional activities, even at exposures to orchestral noise less than the limit values for occupational noise.

Evaluation of annoyance from the wind turbine noise: a pilot study.

OBJECTIVES: The overall aim of this study was to evaluate the perception of and annoyance due to the noise from wind turbines in populated areas of Poland. MATERIAL AND METHODS: The study group comprised 156 subjects. All subjects were asked to fill in a questionnaire developed to enable evaluation of their living conditions, including prevalence of annoyance due to the noise from wind turbines and the self-assessment of physical health and well-being. In addition, current mental health status of the respondents was assessed using Goldberg General Health Questionnaire GHQ-12. For areas where the respondents lived, A-weighted sound pressure levels (SPLs) were calculated as the sum of the contributions from the wind power plants in the specific area. RESULTS: It has been shown that the wind turbine noise at the calculated A-weighted SPL of 30-48 dB was noticed outdoors by 60.3% of the respondents. This noise was perceived as annoying outdoors by 33.3% of the respondents, while indoors by 20.5% of them. The odds ratio of being annoyed outdoors by the wind turbine noise increased along with increasing SPLs (OR = 2.1; 95% CI: 1.22-3.62). The subjects' attitude to wind turbines in general and sensitivity to landscape littering was found to have significant impact on the perceived annoyance. About 63% of variance in outdoors annoyance assessment might be explained by the noise level, general attitude to wind turbines and sensitivity to landscape littering. CONCLUSIONS: Before firm conclusions can be drawn further studies are needed, including a larger number of respondents with different living environments (i.e., dissimilar terrain, different urbanization and road traffic intensity).

Genetic variants of CDH23 associated with noise-induced hearing loss.

OBJECTIVES: Noise-induced hearing loss (NIHL) is a complex disease resulting from the interaction between external and intrinsic/genetic factors. Based on mice studies, one of the most interesting candidate gene for NIHL susceptibility is CDH23-encoding cadherin 23, a component of the stereocilia tip links. The aim of this study was to analyze selected CDH23 single nucleotide polymorphisms (SNPs) and to evaluate their interaction with environmental and individual factors in respect to susceptibility for NIHL in humans. METHODS: A study group consisted of 314 worst-hearing and 313 best-hearing subjects exposed to occupational noise, selected out of 3,860 workers database. Five SNPs in CDH23 were genotyped using real-time PCR. Subsequently, the main effect of genotype and its interaction with selected environmental and individual factors were evaluated. RESULTS: The significant results within the main effect of genotype were obtained for the SNP rs3752752, localized in exon 21. The effect was observed in particular in the subgroup of young subjects and in those exposed to impulse noise; CC genotype was more frequent among susceptible subjects, whereas genotype CT appeared more often among resistant to noise subjects. The effect of this polymorphism was not modified by none of environmental/individual factors except for blood pressure; however, the latter one should be further investigated. Smoking was shown as an independent factor determining NIHL development. CONCLUSION: The results of this study confirm that CDH23 genetic variant may modify the susceptibility to NIHL development in humans, as it was earlier proven in mice. Because the differences between the 2 study groups were not necessarily related to susceptibility to noise but they also were prone to age-related cochlear changes, these results should be interpreted with caution until replication in another population.