Showing 6 results for Hearing
M. Mostafaee, P. Nassiri, M. H. Behzadi,
Volume 5, Issue 2 (7-2015)
Abstract
Introduction: According to previous researches, working at the airport is one of the most vociferous jobs in the world. Airport workers are at risk of noise induced hearing loss. The present study was done to evaluate the Sound Pressure Level (SPL) in the closest aprons to Ground Safety department at Mehrabad airport and to investigate the effect of airport noise on the employees of this department.
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Material and Methods: Evaluation of SPL in the given aprons was done using sound meter and sound analyzer. Measurement stations at specific intervals to the sound source were identified inside and outside of the participants 'workplace and SPL was measured at night and day. The mean estimated values were compared with those presented by Ministry of Health. The annual participants' audiometry information was extracted from medical records. Then a self-administered questionnaire was distributed among the study sample in order to measure quality of noise exposure. The questionnaire was developed based on three general criteria including the knowledge toward the noise pollution, job satisfaction, and the exposure to the noise source and the purpose of this questionnaire was to find the relationship (correlation) between these parameters among the study population.
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Result: The measured equivalent for 8 hours noise exposure was obtained 94 dB(A) and no relation was observed between octave band sound of aircraft and recorded audiometry. Analysis of the questionnaire showed that people with more knowledge about noise pollution used more hearing protective equipment. Subsequently, by using more hearing protection equipment the level of hearing loss was reduced significantly (P<0.05). There was a significant and negative correlation between noise exposure and job satisfaction, as well (P<0.05). Also there was a significant and negative correlation between using of ear muffs and catching Noise-Induced Hearing Loss (P<0.1). The percentage of noise-induced hearing loss was calculated 51.4% among study sample.
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Conclusion: The noise exposure of employees of Ground Safety working in Mehrabad airport was higher than the permissible limit which implies the necessity for use of earmuffs and implementation of noise reduction programs.
Amir Esmael Forouhid, Ali Mansour Khaki,
Volume 6, Issue 2 (6-2016)
Abstract
Introduction: Safe driving requires the ability of the driver to receive the messages and complying with them. The most significant consequences of noise pollution are on the human auditory system. Disorders in the auditory system can have harmful side effects for human health. By reducing this kind of pollution in large cities, the quality of life, which is one of the biggest goals of the governments, can be considerably increased. Hence, in the present research, some parameters of vehicle tires were examined as a source of noise pollution, and the results can be taken into consideration in noise pollution reduction.
Material and Method: Several vehicles with different tire width were selected for measuring sound level. The sound levels were measured for moving vehicles with the use of the Statistical Pass By Method (SPB, ISO 11819-1). Following sound level measurements for moving vehicles and by considering tire width, mathematical model of noise level was predicted on the basis of the obtained information and by usage of SPSS program and considering vehicle tire parameters.
Result: The result of this study showed that the vehicle speed and tire width can affect different sound levels emitted by moving tire on road surface. The average speed of vehicles can play an important role in the noise pollution. By increasing speed, rotation of the the tires on the asphalt is increased, as it is a known factors for noise pollution. Moreover, changing the speed of vehicles is accompanied with abnormal sounds of vehicle engine. According to regression model analysis, the obtained value of R2 for the model is 0.8367 which represents the coefficient of determination.
Conclusion: The results suggest the main role of the vehicle speed and tire width in increasing the noise reaches to the drivers and consequent noise pollution, which demonstrates the necessity for noise control measures. According to the obtained model, it is understood that changes in noise levels and tire width are more than those of vehicles speed. The coefficient of 0.1482 for tire width, comparing to coefficient of 0.1195, shows that considering the proper tire width can be effecttive in reduction of sound level.
Mohammad Reza Monazzam Esmaielpour, Fereydoon Laal, Fereshte Majlessi, Rohollah Fallah Madvari, Abbas Rahimi Foroushani, Alireza Fallah Madvari,
Volume 7, Issue 4 (12-2017)
Abstract
Introduction: The use of hearing protective devices (HPDs) is the last way for noise control. It is important to know the information about the duration time using these devices to ensure protetion effectiveness. The aim of this study was to investigate the effect of increasing duration time of the using of the devices on hearing loss in tile industry workers with application of the BASNEF education model.
Material and Method: Task Base Method (TBM) and ISO9612(2009) standard methods through a noise dosimeter device were used to exmine workers’ noise exposure level when they didn’t used of HPDs. Actual performance of HPDs was determined by using the NIOSH standard before and after training intervention and measuring time of use and protection device type. Data were analyzed using SPSSVv19 and conducting t-test and ANCOVA statistical tests.
Result: Before training intervention, the actual noise level for case workers was 89.76 dBA. On the contrary, this value was 84.04 dBA for after intervention, with a significant difference with control group (P<0.0001) using ANCOVA analysis. In control group, the actual level of noise has not changed because this group has not received any training.
Conclusion: The results revealed that, based on BASNEF education model, duration time of using hearing protection devices is effective on increasing their function and performance.
Monireh Khadem, Elham Kazemi Rad, Mohammad Reza Monazzam Esmaeilpoor, Maryam Mirzaei Hotkani, Sajjad Mozaffari, Amir Abbasi Garmaroudi,
Volume 12, Issue 1 (3-2022)
Abstract
Introduction: One of the most important complications of exposure to noises is changes in the gene expression patterns. Irreversible damage to the inner ear, such as noise-induced hearing loss (NIHL), is caused by tissue damage and changes in the gene expressions in the auditory system. Changes in the GJB2 gene expression pattern lead to autosomal deafness at different loci. The present study aims to evaluate the GJB2 gene expression in cochlear tissue exposed to white noise.
Material and Methods: In this study, ten male Westar rats were divided into two experimental (W1, W2) groups of six rats and a control (normal) group of four rats. Two experimental groups were exposed to constant white noise in the frequency range of 100-20000 Hz and the sound pressure level of 118-120 dB. In order to study the histology and gene expression, after a cochlea biopsy, the histological tests, RNA extraction, cDNA synthesis, and qRT-PCR analysis were performed.
Results: The results showed that the transcript level of GJB2 was significantly decreased in both experimental groups W1 and W2 by 0.02 and 0.12-fold, respectively (p <0.05). Also, the results of the histological study showed that cochlear tissue was more seriously damaged in the W1 group than W2.
Conclusion: It can be concluded that a significant reduction in the GJB2 gene expression and irrevocable damage to auditory nerve ganglion and Reissner membrane (vestibular membrane) caused changes in the gene expression patterns in cochlear tissue and developed the risk of non-syndromic sensorineural hearing.
Vida Rezaei-Hachesu, Hassan Haddadzade Niri, Saeid Farahani, Mohammad Reza Monazzam Esmaeelpour,
Volume 13, Issue 2 (6-2023)
Abstract
Introduction: Colored noises with acoustic and psychoacoustic characteristics have several biological effects on human or animal health. While studies on auditory effects focus on noise’s physical aspects, its psychoacoustic aspects can also result in health and safety risks. Therefore, this study aims to investigate frequency-based damages due to exposure to colored noise in an animal model.
Material and Methods: Twenty-four male Wistar rats were randomly divided into four groups (6 in each group). The groups included the control (no exposure) and three exposure groups (white, pink, and violet). The rats were exposed to 110 dB SPL for 4 hr/day for 14 consecutive days. Auditory brainstem responses (ABR) with click and tone-burst stimuli were recorded one day before (baseline), 7, and 14 days after exposure. Statistical analyses were conducted using ANOVA and repeated measures ANOVA.
Results: There was a statistically significant increase in ABR threshold values in exposure groups (p<0.05). Hearing threshold shifts in the white noise group showed a homogeneous pattern, violet noise showed an increasing pattern, and pink noise showed a decreasing pattern in low frequencies and a homogeneous pattern with increasing frequency. The highest shift in hearing threshold was observed in exposure groups from day 0 to 14. Additionally, the shift in hearing threshold in the second week was less than in the first one.
Conclusion: The current study observed that noise’s power spectral density affected hair cells’ damage severity. Accordingly, pink noise causes less damage to the cochlea compared to white and violet. Over time after noise exposure, cochlear pathogenesis gradually decreases and hair cell lesions become stable.
Fatemeh Fasih-Ramandi, Farideh Golbabaei, Hadi Shakibian, Seyed Mohammad Asadzadeh, Mohammad Reza Monazzam-Esmaeelpour,
Volume 13, Issue 4 (12-2023)
Abstract
Introduction: To ensure employee safety and health, it is crucial to choose and use personal protective equipment correctly. An investigation of the respiratory and hearing protection equipment used in the industries of Tehran was conducted in the present study.
Material and Methods: This study was a descriptive-analytical study conducted in 2023 on 400 occupational health and safety experts in Tehran province. A researcher-made checklist and questionnaire (physical and online versions) were used to determine the criteria that are considered when selecting protective equipment. Statistical analysis and graphing were performed using SPSS-v21 and Excel-2016.
Results: Participants had an average age of 38.66 and an average work experience of 11.78 years. The participants reported 48.3% and 47.7% disapproval of the quality and 42.5% and 39.5% disapproval respectively of the quantity of respiratory and hearing protection equipment available in their industrial units. In addition, 56.3% of them admitted that they have no responsibility for providing or approving the equipment in their workplace. Overall, 27 and 29 criteria were mentioned by study participants pertaining to respiratory and hearing protection equipment, respectively. In the identified criteria, the frequency distribution ranged from 0.3% to 38%.
Conclusion: A high rate of expert dissatisfaction with protective equipment and a low frequency of most of the criteria mentioned indicates that industries aren’t paying much attention to the issue of choosing the right respiratory and hearing protection equipment. To improve the situation, more investigation is needed and practical and operational solutions will be provided. This study highlights the importance of proper selection and use of personal protective equipment in ensuring the safety and health of employees.
