Evaluation of Digits-in-Noise Test and Hearing Handicap Inventory for Adults Screening in Patients with Occupational Noise-Induced Hearing Loss

Objective:To explore the clinical evaluation role of the Digits-in-Noise(DIN)test and Hearing Handicap Inventory for Adults Screening(HHIA-S)for patients with occupational noise-induced hearing loss and to observe and analyze their application values.Methods:Fifty patients with suspected occupational noise-induced hearing loss were randomly selected from the Department of Otolaryngology at the hospital as the research target.The collection period for the research cases spanned from January 2022 to November 2023,and all patients had a history of noise exposure.The DIN test and HHIA-S were used for hearing examinations,with clinical,comprehensive diagnosis serving as the gold standard to study their diagnostic performance.Results:The compliance rate of the DIN test was 88.00%,the HHIA-S’s compliance rate was 80.00%,and the combined compliance rate was 94.00%.The compliance rate of the DIN test and the combined compliance rates of the patients were statistically significant compared to the clinical gold standard data(P<0.05),while there was no difference between the compliance rate of the HHIA-S and the gold standard(P>0.05).The data shows that the sensitivity of the combined diagnosis is significantly higher than the sensitivity data of the DIN test and HHIA-S examination alone(P<0.05).Its specificity is 100.00%,and the accuracy data of the joint diagnosis in the degree were higher than those of the DIN test alone(P>0.05)and the HHIA-S alone(P<0.05).Conclusion:For patients with occupational noise-induced hearing loss,the joint evaluation of the DIN test and HHIA-S can significantly improve their diagnostic value with high sensitivity and accuracy.

The Effect of a High-Frequency-Hearing-Threshold Weighted Value on the Diagnosis of Occupational-Noise-Induced Deafness

Objective: In order to provide a theoretical basis for the revision of the current diagnostic criteria for occupational noise-induced deafness (ONID), we evaluated the degree of ONID by analyzing different high-frequency-hearing- threshold-weighted values (HFTWVs). Methods: A retrospective study was conducted to evaluate the diagnosis of patients with ONID from January 2016 to January 2017 in Guangdong province, China. Based on 3 hearing tests (each interval between the tests was greater than 3 days), the minimum threshold value of each frequency was obtained using the 2007 edition’s diagnostic criteria for ONID. The speech frequency and the HFTWVs were analyzed based on age, noise exposure, and diagnostic classi-fication using SPSS21.0. Results: 168 patients in total were involved in this study, 154 males and 14 females, and the average age was 41.18 ± 6.07. The diagnosis rate was increased by the weighted value of the high frequencies and was more than the mean value of the pure speech frequency (MVPSF). The diagnosis rate for the weighted 4 kHz frequency level increased by 13.69% (χ2 = 9.880, P = 0.002), the weighted 6 kHz level increased by 15.47% (χ2 = 9.985, P = 0.002), and the weighted 4 kHz + 6 kHz level increased by 15.47% (χ2 = 9.985, P = 0.002). The differences were all statistically significant. The diagnostic rate of the different thresholds showed no obvious difference between the genders. The age groups were divided into less than or equal to 40 years old (group A) and 40 - 50 years old (group B). There were several groups with a high frequency: high frequency weighted 4 kHz ( group A χ2 = 3.380, P = 0.050;group B χ2 = 4.054, P = 0.032), high frequency weighted 6 kHz (group A χ2 = 6.362, P = 0.012;group B χ2 = 4.054, P = 0.032), weighted 4 kHz + 6 kHz (group A χ2 = 6.362 P = 0.012;B χ2 = 4.054, P = 0.032) than those of MVPSF in the same group on ONID diagnosis rate. The differences between the groups were statistically significant. There was no significant difference between the age groups (χ2 = 2.265, P = 0.944). The better ear’s (the smaller hearing threshold weighted value) MVPSF and the weighted values for the different high frequencies were examined in light of the number of working years;the group that was exposed to noise for more than 10 years had significantly higher values than those of the average thresholds of each frequency band in the groups with 3 - 5 years of exposure (F = 2.271, P = 0.001) and 6 - 10 years of exposure (F = 1.563, P = 0.046). The differences were statistically significant. The different HFTWVs were higher than those of the MVPSF values, and the high frequency weighted 4 kHz + 6 kHz level showed the greatest difference, with an average increase of 2.83 dB. The diagnostic rate that included the weighted high frequency values was higher for the mild, moderate, and severe cases than those patients who were only screened with the pure frequency tests. The results of the comparisons of the diagnosis rates for mild ONID were as follows: the weighted 3 kHz high frequency level (χ2 = 3.117, P = 0.077) had no significant difference, but the weighted 4 kHz level (χ2 = 10.835, P = 0.001), 6 kHz level (χ2 = 9.985, P = 0.002), 3 kHz + 4 kHz level (χ2 = 6.315, P = 0.012), 3 kHz + 6 kHz level (χ2 = 6.315, P = 0.012), 4 kHz + 6 kHz level (χ2 = 9.985, P = 0.002), and 3 kHz + 4 kHz + 6 kHz level (χ2 = 7.667, P = 0.002) were significantly higher than the diagnosis rate of the mean value of the PSF. There was no significant difference between the 2 groups for the moderate and severe grades (P > 0.05). Conclusion: Different HFTWVs increase the diagnostic rate of ONID. The weighted 4 kHz, 6 kHz, and 4 kHz + 6 kHz high frequency values greatly affected the diagnostic results, and the weighted 4 kHz + 6 kHz high frequency hearing threshold value has the maximum the effect on the ONID diagnosis results.

Analysis of occupational noise for the healthy life according to the job characteristics

Noise is known that the physical risk factors defined as any unwanted sound. It can induce the health problems such as hearing loss or annoyance. The objective of this study was to assess the occupational noise exposure of nine groups for twenty peoples according to job characteristics and to compare the noise level by different variables. Personal noise levels were measured for three times using by dosimeters for each participant in Korea. The mean time weighted average noise level (TWA) of total was 73.2 ± 11.5 dBA by American conference of governmental industrial hygienists (ACGIH) standard. Especially, Korean classical music students were highly exposed to 93.2 ± 6.2 dBA but, office workers were 63.2 ± 6.6 dBA. In case of peak sound pressure level (Lpeak), Korean classical music students and firefighters were exposed to the highest level of 151.8 dBC and 145.8 dBC during playing and dispatching, respectively. The analysis of noise level showed that Leq had positive correlations between TWA by ministry of employment and labour (MOEL) (r = 0.98, p < 0.01) and TWA by ACGIH (r = 0.98, p < 0.01). Unlikely other groups, the noise exposure level of the Korean classical music students were exceeded the ACGIH standard. These results suggest that Korean classical music students were exposed high noise level and some solutions are need to reduce the noise exposure level such as using hearing protect device.

A cross-sectional study on the effects of occupational noise exposure on hypertension or cardiovascular among workers from automobile manufacturing company of Chongqing, China

For the past few years, noise pollution has been more and more serious, and it may lead to several diseases. While the humans expose to noise in quantity for a long time, their blood pressure will change, and even cause changes in cardiac function. In our study, we attempt to find the relationship between occupational noise and hypertension and impaired hearing, cardiac function. It may be helpful to obtain some useful information on occupational noise exposure of humans. The participants were divided into noisy group ≥90 dB (A) and non-noisy group ≤70 dB (A). We performed this research in an automobile manufacturing company of Chongqing, China during 2011-2012. Our study showed that there may be positive associations between?occupational noise and hypertension and impaired hearing, but no conclusion can be drawn between occupational noise and ECG.

Assessment of occupational noise pollution for metal industries in Kingdom of Saudi Arabia

The main objectives of this study was measuring levels of noise generated by machinery that workers at metal industrial facilities in the Kingdom of Saudi Arabia （KSA） are exposed to as well as to determine if these levels were in conformity with adopted standards. To achieve the objectives of this study the following six metal industrial facilities were selected： a foundry plant, a building-metal production factory, a cold processing steel manufacturing plant, a hollow-metal door and doorframe manufacturer, a car-exhaust-system factory and a metal-can producer. The study found that workers operating machinery without any kind of protection were exposed to unacceptably high levels of noise that exceeded the internationally acceptable values as per occupational noise exposure-1910.95 regulations adopted standard. It was founded that 73% of work site investigated have noise level over 85 dB. A level of 116 dB was recorded at steel plant fiat section product with continuous occupation and 115.2 dB in metal product factory with labor continuous occupation. Based on the results obtained in this study, it is evident that a competent environmental and health agency needs to be established and that stricter noise-level standards ought to be enforced in order to protect employee health.

Effects of Occupational Noise on the Hearing Ability of Outpatient Clinic Nurses in Different Classes of Hospitals in Guangzhou

Background: Occupational noise can induce hearing impairment. Work-related hearing impairment has become a growing threat to medical practitioners who feel anxious about occupational noise exposure and its health outcomes or even experience auditory dysesthesia (including drumming, distending pain in the ears, and otalgia) after long-term exposure to a noisy work environment. Objective: To investigate the effects of occupational noise on the hearing ability of outpatient clinic nurses in Grade III, Level A and Grade II, Level A hospitals in Guangzhou. Methods: During June 2019, noise monitoring was performed by quantifying the noise levels at four measuring points (reception, waiting area, hallway, blood-sampling room) in five Grade III, Level A and five Grade II, Level A hospitals, in Guangzhou, four times a day (8 AM, 10 AM, 2 PM, and 4 PM) for 19 working days, using a professional noise measuring application for smartphones. The measurements were verified and used to create a database in Excel. Data analysis was conducted using SPSS22.0, and questionnaires were distributed to nurses who had been working at outpatient clinics for five years and above to assess the impacts of occupational noise exposure on the hearing ability. Results: In the Grade III, Level A hospitals, the sound levels at the four measuring points during the specific time periods were 4.92 - 6.75 dB above the permissible limit of 55 dB and were all significantly higher than the sound levels at the outpatient clinics of the Grade II, Level A hospitals (P Conclusions: Exposure to excess noise can lead to auditory dysesthesia in outpatient clinic nurses. Compared to those from Grade II, Level A hospitals, outpatient clinic nurses from Grade III, Level A hospitals are at higher risk of auditory dysesthesia. The noise levels at outpatient clinics should be closely monitored, and effective measures should be taken to reduce occupational noise exposure. Outpatient clinic nurses should enhance protective measures and receive preventive health exams on a regular basis.

Reducing Occupational Noise Propagated from Centrifugal Fan through Dissipative Silencers:A Field Study

Acoustic performance of dissipative silencer was evaluated to determine the effectiveness of perforated duct porosity and absorbent material density in reducing occupational noise exposure propagated from centrifugal fan.Design charts were applied to predict noise reduction and length of a dissipative silencer.Dissipative silencers with various punched duct porosity(14%,30%and 40%)and sound absorbent density(80 Kg/m^(3),120 Kg/m^(3),and 140 Kg/m^(3))were designed and fabricated.According to ISO9612 and ISO11820,noise level was measured before and after installing all nine test silencers at fixed workstations around the discharge side of a centrifugal fan in a manufacturing plant.On average,the noise level at the discharge side of a fan without silencer was measured to be 93.6 dBA,whereas it was significantly mitigated by 67.4 dBA to 70.1 dBA after installing all silencers.Dynamic insertion loss for a dissipative silencer with 100 cm length was predicted to be 27.9 dB,which was in agreement with experimental ones.Although,there was no significant differences between insertion loss of silencers,the one with 30%porosity and 120 Kg/m^(3)rock wool density had the highest insertion loss of 26.2 dBA.Dissipative silencers noticeably reduced centrifugal fan noise exposures.Increasing sound absorbent density and duct porosity up to a certain limit could probably be effective in noise reduction of dissipative silencers.

Influence of Occupational Noise Exposure on Cognitive Ability of Grinders

Purpose: To investigate whether long-term noise exposure affects the cognitive ability of grinders. Methods: Cumulative noise exposure (CNE) and LAeq.8h determination were used to characterize the level of individual noise exposure;the Montreal Cognitive Assessment (MoCA) test (Beijing version) was used to evaluate cognitive function. Results: We compared the basic situation of workers in different groups and individual noise exposure intensity of grinders was monitored. Multiple linear-regression analysis was made and score of MoCA in different group was finally drawn. Conclusion: CNE and total score of MoCA have the relationship of negative correlation (r = -0.303, p < 0.05) which means long-term occupational noise exposure can affect the cognitive ability of grinders.

Positive Associations between Bilateral High-Frequency Hearing Loss and Hypertension Risk in Short-Term Occupational Noise Exposure

Noise is one of the most common occupational hazards worldwide[1], and millions of workers are exposed to harmful levels of noise in the workplace[2]. Noise-induced hearing loss(NIHL) is a leading cause of occupational and recreational injury and disease[3]. There is evidence that occupational noise exposure is also associated with other health effects, such as hypertension and cardiovascular diseases, digestive disorders, behavioral disorders.

The comparison of auditory behavioral and evoked potential responses (steadystate and cortical) in subjects with occupational noise-induced hearing loss

Objective: To define difference scores between PTA, ASSR and CERA thresholds in subjects with occupational NIHL.Design: 44 subjects undergoing a medico-legal expert assessment for occupational NIHL and fulfillingcriteria of reliability were considered. Assessment included: PTA, 40 Hz binaural multiple ASSR and CERA(1-2-3 kHz).Results: The respective average difference scores (ASSR - PTA) for 1, 2 and 3 kHz are 13.01 (SD 10.19) dB,12.72 (SD 8.81) dB and 10.38 (SD 8.19) dB. The average (CERA - ASSR) difference scores are 1.25 (SD 14.63)dB for 1 kHz (NS), 2.73 (SD 13.03) dB for 2 kHz (NS) and 4.51 (SD 12.18) dB for 3 kHz. The correlationbetween PTA and ASSR (0.82) is significantly stronger than that between PTA and CERA (0.71). In a givensubject, PTA thresholds are nearly always lower (i.e., better) than ASSR thresholds, whatever the frequency (1-2-3 kHz) and the side (right e left). A significant negative correlation is found between thedifference score (ASSR e PTA) and the degree of hearing loss.Conclusion: ASSR outperforms CERA in a medicolegal context, although overestimating the behavioralthresholds by 10e13 dB.

A Systematical Approach for Noise in CMOS LNA

A systematic approach is used to analyze the noise in CMOS low noise amplifier(LNA),including channel noise and induced gate noise in MOS devices.A new analytical formula for noise figure is proposed.Based on this formula,the impacts of distributed gate resistance and intrinsic channel resistance on noise performance are discussed.Two kinds of noise optimization approaches are performed and applied to the design of a 5 2GHz CMOS LNA.

Noise reduction mechanism of high-speed railway box-girder bridges installed with MTMDs on top plate

The issue of low-frequency structural noise radiated from high-speed railway(HSR) box-girder bridges(BGBs) is a significant challenge worldwide. Although it is known that vibrations in BGBs caused by moving trains can be reduced by installing multiple tuned mass dampers(MTMDs) on the top plate, there is limited research on the noise reduction achieved by this method. This study aims to investigate the noise reduction mechanism of BGBs installed with MTMDs on the top plate. A sound radiation prediction model for the BGB installed with MTMDs is developed, based on the vehicle–track–bridge coupled dynamics and acoustics boundary element method. After being verified by field tested results, the prediction model is employed to study the reduction of vibration and noise of BGBs caused by the MTMDs. It is found that installing MTMDs on top plate can significantly affect the vibration distribution and sound radiation law of BGBs. However, its impact on the sound radiation caused by vibrations dominated by the global modes of BGBs is minimal. The noise reduction achieved by MTMDs is mainly through changing the acoustic radiation contributions of each plate of the bridge. In the lower frequency range, the noise reduction of BGB caused by MTMDs can be more effective if the installation of MTMDs can modify the vibration frequency and distribution of the BGB to avoid the influence of small vibrations and disperse the sound radiation from each plate.

Adaptive Bistable Stochastic Resonance Based Weak Signal Reception in Additive Laplacian Noise

Weak signal reception is a very important and challenging problem for communication systems especially in the presence of non-Gaussian noise,and in which case the performance of optimal linear correlated receiver degrades dramatically.Aiming at this,a novel uncorrelated reception scheme based on adaptive bistable stochastic resonance(ABSR)for a weak signal in additive Laplacian noise is investigated.By analyzing the key issue that the quantitative cooperative resonance matching relationship between the characteristics of the noisy signal and the nonlinear bistable system,an analytical expression of the bistable system parameters is derived.On this basis,by means of bistable system parameters self-adaptive adjustment,the counterintuitive stochastic resonance(SR)phenomenon can be easily generated at which the random noise is changed into a benefit to assist signal transmission.Finally,it is demonstrated that approximately 8dB bit error ratio(BER)performance improvement for the ABSR-based uncorrelated receiver when compared with the traditional uncorrelated receiver at low signal to noise ratio(SNR)conditions varying from-30dB to-5dB.

Wind Turbine Noise Reduction through Blade Retrofitting

This paper outlines a plan for the effective reduction of the audible sound level produced by aerodynamic noise from the power-generating turbine blades. The contribution of aerodynamic noise can be divided into two categories: inflow turbulence and airfoil self-noise. The base model and retrofit blade designs were modeled in SolidWorks. Subsequently, noise prediction simulations were conducted and compared to the base blade model to determine which modification provided the greatest benefit using SolidWorks Flow Simulation. The result of this project is a series of blade retrofit recommendations that produce a more acoustically efficient design and reduce noise complaints while enabling turbines to be placed in locations that require quieter operations.

Mixed noise removal for color images using quaternion representation

In order to effectively restore color noisy images with the mixture of Gaussian noise and impulse noise,a new algorithm is proposed using the quaternion-based holistic processing idea for color images.First,a color image is represented by a pure quaternion matrix.Secondly,according to the different characteristics of the Gaussian noise and the impulse noise,an algorithm based on quaternion directional vector order statistics is used to detect the impulse noise. Finally,the quaternion optimal weights non-local means filter （QOWNLMF）for Gaussian noise removal is improved for the mixed noise removal.The detected impulse noise pixels are not considered in the calculation of weights.Experimental results on five standard images demonstrate that the proposed algorithm performs better than the commonly used robust outlyingness ratio-nonlocal means （ROR-NLM）algorithm and the optimal weights mixed filter （OWMF）.

Implementation and noise optimization of a 433 MHz low power CMOS LNA

A low power 433 MHz CMOS （complementary metal- oxide-semiconductor transistor） low noise amplifier（LNA）, used for an ISM （ industrial-scientific-medical ） receiver, is implemented in a 0. 18 μm SMIC mixed-signal and RF （ radio frequency） CMOS process. The optimal noise performance of the CMOS LNA is achieved by adjusting the source degeneration inductance and by inserting an appropriate capacitance in parallel with the input transistor of the LNA. The measured results show that at 431 MHz the LNA has a noise figure of 2.4 dB. The S21 is equal to 16 dB, S11 = -11 dB, S22 = -9 dB, and the inverse isolation is 35 dB. The measured input 1-dB compression point （PtdB） and input third-order intermodulation product （IIP3）are - 13 dBm and -3 dBm, respectively. The chip area is 0. 55 mm × 1.2 mm and the DC power consumption is only 4 mW under a 1.8 V voltage supply.

Random noise stimulation in the treatment of patients with neurological disorders

Random noise stimulation technique involves applying any form of energy(for instance,light,mechanical,electrical,sound)with unpredictable intensities through time to the brain or sensory receptors to enhance sensory,motor,or cognitive functions.Random noise stimulation initially employed mechanical noise in auditory and cutaneous stimuli,but electrical energies applied to the brain or the skin are becoming more frequent,with a series of clinical applications.Indeed,recent evidence shows that transcranial random noise stimulation can increase corticospinal excitability,improve cognitive/motor performance,and produce beneficial aftereffects at the behavioral and psychological levels.Here,we present a narrative review about the potential uses of random noise stimulation to treat neurological disorders,including attention deficit hyperactivity disorder,schizophrenia,amblyopia,myopia,tinnitus,multiple sclerosis,post-stroke,vestibular-postural disorders,and sensitivity loss.Many of the reviewed studies reveal that the optimal way to deliver random noise stimulation-based therapies is with the concomitant use of neurological and neuropsychological assessments to validate the beneficial aftereffects.In addition,we highlight the requirement of more randomized controlled trials and more physiological studies of random noise stimulation to discover another optimal way to perform the random noise stimulation interventions.

Assessment of Traffic Noise Pollution in Burla Town,India;An InclusiveAnnoyance Study

Noise pollution is one of the major public health problems in urban areas throughout the world.Noise is unwanted sound which produces undesirable problems in day to day life of human being(e.g.,physiological and psychological problems).Rapid increase of the industrialization,urbanization,infrastructure,volume of motor vehicles,and increase in the road networks brought noise pollution to the highest level of disaster in a current situation.In urban areas,road traffic noise plays commanding role among all noise sources and affects the exposed inhabitants.The present work is done to evaluate and assess the traffic noise and its effects in Burla town.Burla,Vidyanagari of Odisha,is an emerging town in India,as it hosts national level of teaching and research institutions like IIM Sambalpur,a medical college-cum-hospital(VIMSAR),a technical university(VSSUT)and Sambalpur University.In last two decade,the road traffic volume has been increased and is facing severe noise pollution to its inhabitants.Noise pollution assessment was made at different locations of the town.This study unveiled the dismal state of noise pollution in the town.Noise contour maps were drawn to visualize the noise level at the traffic and its surroundings.The numbers of hearing impaired patients in different hospitals of the locality are increasing.That shows grim picture of the situation.Regression equations were established taking noise levels with percentage of highly annoyed people during study indicates strong correlation.

Occupational Noise Levels in Two Fish Rearing Buildings at an Aquaculture Facility

Occupational noise is commonly encountered during aquaculture. This study documented noise levels in two buildings at a production fish hatchery, a tank room with 32, 1.8-m diameter tanks, and a rearing pavilion with 32, 6.1-m diameter tanks. With water flowing to all of the tanks in the tank room, mean noise levels were 68.4 dB, and significantly increased to 73.0 dB during tank cleaning and 73.2 dB when intermittent automatic feeders were running. The highest tank room values of 77.1 dB were recorded directly next to individual tanks during cleaning. With water flowing to all of the tanks in the rearing pavilion, mean noise levels were 70.2 dB. A significant increase to 76.1 dB was observed when the pavilion tanks were being power washed, with the highest value of 83.2 dB recorded immediately adjacent to the power washer. Although none of the noise levels exceeded regulatory limits, the use of techniques to reduce occupational noise in aquaculture environments is recommended.

Numerical Study on Reduction in Aerodynamic Drag and Noise of High-Speed Pantograph

Reducing the aerodynamic drag and noise levels of high-speed pantographs is important for promoting environmentally friendly,energy efficient and rapid advances in train technology.Using computational fluid dynamics theory and the K-FWH acoustic equation,a numerical simulation is conducted to investigate the aerodynamic characteristics of high-speed pantographs.A component optimization method is proposed as a possible solution to the problemof aerodynamic drag and noise in high-speed pantographs.The results of the study indicate that the panhead,base and insulator are the main contributors to aerodynamic drag and noise in high-speed pantographs.Therefore,a gradual optimization process is implemented to improve the most significant components that cause aerodynamic drag and noise.By optimizing the cross-sectional shape of the strips and insulators,the drag and noise caused by airflow separation and vortex shedding can be reduced.The aerodynamic drag of insulator with circular cross section and strips with rectangular cross section is the largest.Ellipsifying insulators and optimizing the chamfer angle and height of the windward surface of the strips can improve the aerodynamic performance of the pantograph.In addition,the streamlined fairing attached to the base can eliminate the complex flow and shield the radiated noise.In contrast to the original pantograph design,the improved pantograph shows a 21.1%reduction in aerodynamic drag and a 1.65 dBA reduction in aerodynamic noise.