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.
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.
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.
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.
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.
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 (L
) of ±2 dB.
The ultrasonic device operators and the control group were exposed to audible noise at L
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.
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.
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 high-frequency 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. Key words: noise-induced hearing loss, pure-tone audiometry, otoacoustic emissions, communication headsets, occupational exposure to noise, extended high-frequency audiometry
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).
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.
The aim of this study was to assess hearing of music students in relation to their exposure to excessive sounds.
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.
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.
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.
: Hearing loss is defined as worsening of hearing acuity and is usually expressed as an increase in the hearing threshold. Tinnitus, defined as "ringing in the ear", is a common and often disturbing ...accompaniment of hearing loss. Hearing loss and environmental exposures to noise are increasingly recognized health problems.
: The objective was to assess whether the exposure-response relationship can be established between exposures to non-occupational noise and permanent hearing outcomes such as permanent hearing loss and tinnitus.
: Computer searches of all accessible medical and other databases (PubMed, Web of Science, Scopus) were performed and complemented with manual searches. The search was not limited to a particular time span, except for the effects of personal listening devices (PLDs). The latter was limited to the years 2008-June 2015, since previous knowledge was summarized by SCENIHR descriptive systematic review published in 2008.
The inclusion criteria were as follows: the exposure to noise was measured in sound pressure levels (SPLs) and expressed in individual equivalent decibel values (L
), the studies included both exposed and reference groups, the outcome was a permanent health effect, i.e., permanent hearing loss assessed with pure-tone audiometry and/or permanent tinnitus assessed with a questionnaire. The eligibility criteria were evaluated by two independent reviewers.
The risk of bias was assessed for all of the papers using a template for assessment of quality and the risk of bias. The GRADE (grading of recommendations assessment, development, and evaluation) approach was used to assess the overall quality of evidence. Meta-analysis was not possible due to methodological heterogeneity of included studies and the inadequacy of data.
Out of 220 references identified, five studies fulfilled the inclusion criteria. All of them were related to the use of PLDs and comprised in total of 1551 teenagers and young adults. Three studies used hearing loss as the outcome and three tinnitus. There was a positive correlation between noise level and hearing loss either at standard or extended high frequencies in all three of the studies on hearing loss. In one study, there was also a positive correlation between the duration of PLD use and hearing loss. There was no association between prolonged listening to loud music through PLDs and tinnitus or the results were contradictory. All of the evidence was of low quality.
The studies are cross-sectional. No study provides odds ratios of hearing loss by the level of exposure to noise.
While using very strict inclusion criteria, there is low quality GRADE evidence that prolonged listening to loud music through PLDs increases the risk of hearing loss and results in worsening standard frequency audiometric thresholds. However, specific threshold analyses focused on stratifying risk according to clearly defined levels of exposure are missing. Future studies are needed to provide actionable guidance for PLDs users. No studies fulfilling the inclusion criteria related to other isolated or combined exposures to environmental noise were identified.
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.
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.
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.
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.
The aim of this review was to summarize the studies on noise-induced hearing loss (NIHL) which were carried out in the countries of Central and Eastern Europe, South-East Europe, and former Soviet ...Union countries or Newly Independent States in the period from 1970 to 2012. The papers were identified by literature search of all accessible medical and other databases (Scopus, PubMed, Medline, etc.) using the terms "noise; hearing loss, NIHL" as key words and country denomination (in alphabetical order: Armenia, Azerbaijan, Belarus, Bulgaria, Bosnia and Herzegovina, Croatia, Czech Republic, Georgia, Hungary, Montenegro, Poland, Romania, Russian Federation, Serbia, Slovakia, Slovenia, former Yugoslavia, Ukraine). This review comprises both papers published in peer-reviewed international journals and articles from local sources. The main papers′ topics included the assessment of the noise hazards in occupational, and very seldom in communal environment, and the prevalence of hearing impairment in employees. Simultaneously, attempts were undertaken to establish the relationship between the degree of hearing impairment and noise exposure. The effect of combined exposures to noise and vibration and/or otoxic chemicals was assessed as well. The influence of environmental, individual, and genetic risk factors on NIHL development was intensively examined. In addition, studies concerning the role of otoacoustic emissions for NIHL monitoring and clinical examinations were conducted. Some animal researches, including molecular genetics, had been also performed. The majority of papers concerned occupational exposures, whereas only a few were dedicated to community noise.
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