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Fulltext Respiratory Motion Correction for Compressively Sampled Free Breathing Cardiac MRI Using Smoothl1-Norm Approximation

Bilal M, Shah JA, Qureshi IM, Kadir K

Int J Biomed Imaging, 2018;2018:7803067.
PMID: 29610569 DOI: 10.1155/2018/7803067

Transformed domain sparsity of Magnetic Resonance Imaging (MRI) has recently been used to reduce the acquisition time in conjunction with compressed sensing (CS) theory. Respiratory motion during MR scan results in strong blurring and ghosting artifacts in recovered MR images. To improve the quality of the recovered images, motion needs to be estimated and corrected. In this article, a two-step approach is proposed for the recovery of cardiac MR images in the presence of free breathing motion. In the first step, compressively sampled MR images are recovered by solving an optimization problem using gradient descent algorithm. TheL1-norm based regularizer, used in optimization problem, is approximated by a hyperbolic tangent function. In the second step, a block matching algorithm, known as Adaptive Rood Pattern Search (ARPS), is exploited to estimate and correct respiratory motion among the recovered images. The framework is tested for free breathing simulated andin vivo2D cardiac cine MRI data. Simulation results show improved structural similarity index (SSIM), peak signal-to-noise ratio (PSNR), and mean square error (MSE) with different acceleration factors for the proposed method. Experimental results also provide a comparison betweenk-tFOCUSS with MEMC and the proposed method.

Matched MeSH terms: Signal-To-Noise Ratio
Effect of noise and pesticide exposures among foggers in Selangor health district offices

Anita, AR., Noor Hassim, I.

Journal of Occupational Safety and Health, 2013;10(1):27-37.
MyJurnal

Fogging activity has become one of the important methods in tackling dengue outbreaks nowadays. Despite this, it is an occupation that has known hazards namely noise and pesticides which can affect the body organs. Based on this knowledge, a cross sectional study was conducted to determine the association between hearing impairment and serum cholinesterase level among foggers from five randomly selected Health District Offices in Selangor. A total of 200 workers comprising of 100 workers exposed to fogging activity and another 100 workers not exposed were randomly selected for this study. Data was obtained through self administered questionnaire, audiometric testing and serum cholinesterase level measurement. The overall prevalence of hearing impairment was 16% with foggers having significant higher prevalence (24%) compared to the non foggers (8%) (χ2=9.52, p=0.002). Measurement of serum cholinesterase showed that exposed workers had lower level compared to the non exposed group. Similarly, those who have hearing impairment had also lower serum cholinesterase level although it was not statistically different. Among all studied factors, age and duration of exposure to fogging activities were statistically different with hearing impairment (p

Matched MeSH terms: Noise
Fulltext Steady state visual evoked potential based BCI as control method for exoskeleton: a review

Norhafizan Ahmad, Raja Ariffin Raja Ghazilla, Muhammad Zikril Hakim Md Azizi

Malaysian Journal of Public Health Medicine, 2016;16(10):0-0.
MyJurnal

Brain Computer Interfaces (BCI) provide a vast possibility in enabling the brain to communicate directly with the computer, hence providing an alternative in controlling the machines without much effort. In fields of rehabilitations robotics, the applications of an exoskeletons in assisting a spinal cord injured (SCI) patients were growing. Steady state visually evoked potentials (SSVEP) based BCIs that utilizes the human visual reactions to the constant flickered stimulus quickly showed its potentials among the BCIs used in rehabilitations devices because of its advantages such as a higher immunity to noises and artefacts and also its robustness compared to other BCIs. Rehabilitation exoskeletons demands an approach that are more user friendly and the aspects of control scheme and mechanical parts that are more focused on assisting the patients in rehabilitations and providing a SCI patients an alternatives to explore their surroundings in a more intuitive ways. This paper highlights the current development trends in SSVEP based BCIs for rehabilitation exoskeletons and proposed the potential research scopes in the future that can improve the effectiveness, and its potential applications in rehabilitations.

Matched MeSH terms: Noise
Prevalence and associated factors of hearing impairment in aviation and manufacturing industry in Selangor

Ahmad Syazrin Muhamad

Journal of Occupational Safety and Health, 2011;8(2):35-44.
MyJurnal

Sound is one of the source of energy generated by vibration and is carried through the air in a form of pressure waves (Frederick, 1975). This pressure waves consist of pulsation or vibration of molecules of an elastic medium such as gas, liquid and even solid (Gerber, 1974). Due to its nature, sound can be irritating when it is excessive. The excessive amount of sound is called noise. Exposure to noise is common to the workers working at the industry. This can lead to hearing loss. Hearing loss is one of the most common health problems in the industrialized world. Working activities have been related to noise exposure due to increase use of machine that generates sounds. Many workers throughout the world experience hazardous noise exposure which is ≥ 85 decibels (dB) (Seter, 1998). Based on the previous study in the European region, most of the employers had difficulties to compensate workers diagnosed with hearing loss or hearing impairment cause by the working nature. (Rachiotis et al., 2006). According to European Survey on Working Conditions, about 7% of the workers considered that their work affects their health in the form of hearing disorders. Occupational risk factors for hearing loss include occupational noise, whole body vibration, work-related diseases and exposure to chemical. In this report, we specified in the noise exposure level of the workers.

Matched MeSH terms: Noise, Occupational
Fulltext The Acquisition, Analyses and Interpretation of fMRI Data: A Study on Functional Specialisation in Primary Auditory Cortices

Yusuf, A.N., Abdul Hamid, K., Mohamad, M., Abd hamid, A.I.

Medicine & Health, 2008;3(2):300-317.
MyJurnal

In this study, functional magnetic resonance imaging (fMRI) is used to investigate func-tional specialisation in human auditory cortices during listening. A silent fMRI paradigm was used to reduce the scanner sound artefacts on functional images. The subject was instructed to pay attention to the white noise stimulus binaurally given at an inten-sity level of 70 dB higher than the hearing level for normal people. Functional speciali-sation was studied using the Matlab-based Statistical Parametric Mapping (SPM5) software by means of fixed effects (FFX), random effects (RFX) and conjunction analyses. Individual analyses on all subjects indicated asymmetrical bilateral activation of the left and right hemispheres in Brodmann areas (BA) 22, 41 and 42, involving the primary and secondary auditory cortices. The percentage of signal change is larger in the BA22, 41 and 42 on the right as compared to the ones on the left (p>0.05). The average number of activated voxels in all the respective Brodmann areas are higher in the right hemisphere than in the left (p>0.05). FFX results showed that the point of maximum intensity was in the right BA41 whereby 599±1 activated voxels were ob-served in the right temporal lobe as compared to 485±1 in the left temporal lobe. The RFX results were consistent with that of FFX. The analysis of conjunction which fol-lowed, showed that the right BA41 and left BA22 as the common activated areas in all subjects. The results confirmed the specialisation of the right auditory cortices in pro-cessing non verbal stimuli.

Matched MeSH terms: Noise
Fulltext Environmental and occupational health impact of bauxite mining in Malaysia: a review

Lee, K.Y., Ho, L.Y., Tan, K.H., Tham, Y.Y., Ling, S.P., Qureshi, A.M., et al.

International Medical Journal Malaysia, 2017;16(2):137-150.
MyJurnal

In the perspective of recent bauxite mining in Malaysia, this review aims to identify the potential
environmental and health impacts on miners and surrounding communities. The environmental issues of
bauxite mining include, air, water and soil pollution due to bauxite dust; leaching of bauxite into water
sources resulting in reduced soil fertility as well as affecting agricultural food products and aquatic life.
Bauxite occupational exposure affects the health of miners, and has negative consequences on the health of
surrounding communities, such as increased respiratory symptoms, contamination of drinking water, other
potential health risks from ingestion of bauxite and heavy metals, including noise-induced hearing loss and
mental stress. This review discusses the processes of bauxite mining, its constituents and residual trace
elements, and their impact on the environment and health of exposed workers and communities. It also
explores the Malaysian legal requirements and standards of occupational exposure to bauxite.

Matched MeSH terms: Hearing Loss, Noise-Induced
Fulltext Region of Interest-Based Tamper Detection and Lossless Recovery Watermarking Scheme (ROI-DR) on Ultrasound Medical Images

Khor HL, Liew SC, Zain JM

J Digit Imaging, 2017 Jun;30(3):328-349.
PMID: 28050716 DOI: 10.1007/s10278-016-9930-9

Tampering on medical image will lead to wrong diagnosis and treatment, which is life-threatening; therefore, digital watermarking on medical image was introduced to protect medical image from tampering. Medical images are divided into region of interest (ROI) and region of non-interest (RONI). ROI is an area that has a significant impact on diagnosis, whereas RONI has less or no significance in diagnosis. This paper has proposed ROI-based tamper detection and recovery watermarking scheme (ROI-DR) that embeds ROI bit information into RONI least significant bits, which will be extracted later for authentication and recovery process. The experiment result has shown that the ROI-DR has achieved a good result in imperceptibility with peak signal-to-noise ratio (PSNR) values approximately 48 dB, it is robust against various kinds of tampering, and the tampered ROI was able to recover to its original form. Lastly, a comparative table with the previous research (TALLOR and TALLOR-RS watermarking schemes) has been derived, where these three watermarking schemes were tested under the same testing conditions and environment. The experiment result has shown that ROI-DR has achieved speed-up factors of 22.55 and 26.65 in relative to TALLOR and TALLOR-RS watermarking schemes, respectively.

Matched MeSH terms: Signal-To-Noise Ratio
Rigid/flexible polyurethane foam composite boards with addition of functional fillers: acoustics evaluations

Huang C, Lou C, Chuang Y, Lin J, Liu C, Yu Z

Sains Malaysiana, 2015;44:1757-1763.

Following rapid technological and industrial development, factories have been equipped with a great deal of machines.
The blend of industrial and residential areas in turn resulted in many environmental problems. In particular, machine
operation causes noise pollution that easily causes physiological and psychological discomfort for the human body thus
makes noise abatement a crucial and urgent issue. In this study, vermiculite functional fillers were added to polyurethane
(PU) foam mixtures in order to form sound absorbent PU foams. The correlations between the contents of functional fillers
and the sound absorption of flexible and rigid PU foams were then examined. The optimal PU foams were combined with
PET/carbon fiber matrices in order to yield the electromagnetic shielding effectiveness. The sound absorption, noise
reduction coefficient (NRC), electromagnetic shielding effectiveness and resilience rate of the composite boards were
finally evaluated. The test results indicated that rigid PU foam composites can reach a sound absorption coefficient of
0.8 while the flexible PU foam composites have higher mechanical properties.

Matched MeSH terms: Noise
Vehicular traffic noise prediction and propagation modelling using neural networks and geospatial information system

Ahmed AA, Pradhan B

Environ Monit Assess, 2019 Feb 26;191(3):190.
PMID: 30809746 DOI: 10.1007/s10661-019-7333-3

This study proposes a neural network (NN) model to predict and simulate the propagation of vehicular traffic noise in a dense residential area at the New Klang Valley Expressway (NKVE) in Shah Alam, Malaysia. The proposed model comprises of two main simulation steps: that is, the prediction of vehicular traffic noise using NN and the simulation of the propagation of traffic noise emission using a mathematical model. First, the NN model was developed with the following selected noise predictors: the number of motorbikes, the sum of vehicles, car ratio, heavy vehicle ratio (e.g. truck, lorry and bus), highway density and a light detection and ranging (LiDAR)-derived digital surface model (DSM). Subsequently, NN and its hyperparameters were optimised by a systematic optimisation procedure based on a grid search approach. The noise propagation model was then developed in a geographic information system (GIS) using five variables, namely road geometry, barriers, distance, interaction of air particles and weather parameters. The noise measurement was conducted continuously at 15-min intervals and the data were analysed by taking the minimum, maximum and average values recorded during the day. The measurement was performed four times a day (i.e. morning, afternoon, evening, and midnight) over two days of the week (i.e. Sunday and Monday). An optimal radial basis function NN was used with 17 hidden layers. The learning rate and momentum values were 0.05 and 0.9, respectively. Finally, the accuracy of the proposed method achieved 78.4% with less than 4.02 dB (A) error in noise prediction. Overall, the proposed models were found to be promising tools for traffic noise assessment in dense urban areas.

Matched MeSH terms: Noise, Transportation
Fulltext CT brain image advancement for ICH diagnosis

Shaik Amir NS, Kang LZ, Mukari SA, Sahathevan R, Chellappan K

Healthc Technol Lett, 2020 Feb;7(1):1-6.
PMID: 32190334 DOI: 10.1049/htl.2018.5003

A critical step in detection of primary intracerebral haemorrhage (ICH) is an accurate assessment of computed tomography (CT) brain images. The correct diagnosis relies on imaging modality and quality of acquired images. The authors present an enhancement algorithm which can improve the clarity of edges on CT images. About 40 samples of CT brain images with final diagnosis of primary ICH were obtained from the UKM Medical Centre in Digital Imaging and Communication in Medicine format. The images resized from 512 × 512 to 256 × 256 pixel resolution to reduce processing time. This Letter comprises of two main sections; the first is denoising using Wiener filter, non-local means and wavelet; the second section focuses on image enhancement using a modified unsharp masking (UM) algorithm to improve the visualisation of ICH. The combined approach of Wiener filter and modified UM algorithm outperforms other combinations with average values of mean square error, peak signal-to-noise ratio, variance and structural similarity index of 2.89, 31.72, 0.12 and 0.98, respectively. The reliability of proposed algorithm was evaluated by three blinded assessors which achieved a median score of 65%. This approach provides reliable validation for the proposed algorithm which has potential in improving image analysis.

Matched MeSH terms: Signal-To-Noise Ratio
So much for the city: Urban-rural song variation in a widespread Asiatic songbird

Hill SD, Aryal A, Pawley MDM, Ji W

Integr Zool, 2018 Mar;13(2):194-205.
PMID: 29078034 DOI: 10.1111/1749-4877.12284

Song plays a fundamental role in intraspecific communication in songbirds. The temporal and structural components of songs can vary in different habitats. These include urban habitats where anthropogenic sounds and alteration of habitat structure can significantly affect songbird vocal behavior. Urban-rural variations in song complexity, song length and syllable rate are not fully understood. In this study, using the oriental magpie-robin (Copsychus saularis) as a model, we investigated urban-rural variation in song complexity, song length, syllable rate, syllable length and inter-syllable interval. Comparing urban and rural songs from 7 countries across its natural Asiatic range (Bangladesh, India, Malaysia, Nepal, Singapore, Sri Lanka and Thailand), we found no significant differences in oriental magpie-robin song complexity. However, we found significant differences in temporal song variables between urban and rural sites. Longer songs and inter-syllable intervals in addition to slower syllable rates within urban sites contributed the most to this variance. This indicates that the urban environment may have driven production of longer and slower songs to maximize efficient transmission of important song information in urban habitats.

Matched MeSH terms: Noise
A critical review of hearing-aid single-microphone noise-reduction studies in adults and children

Chong FY, Jenstad LM

Disabil Rehabil Assist Technol, 2018 08;13(6):600-608.
PMID: 29072542 DOI: 10.1080/17483107.2017.1392619

PURPOSE: Single-microphone noise reduction (SMNR) is implemented in hearing aids to suppress background noise. The purpose of this article was to provide a critical review of peer-reviewed studies in adults and children with sensorineural hearing loss who were fitted with hearing aids incorporating SMNR.
METHOD: Articles published between 2000 and 2016 were searched in PUBMED and EBSCO databases.
RESULTS: Thirty-two articles were included in the final review. Most studies with adult participants showed that SMNR has no effect on speech intelligibility. Positive results were reported for acceptance of background noise, preference, and listening effort. Studies of school-aged children were consistent with the findings of adult studies. No study with infants or young children of under 5 years old was found. Recent studies on noise-reduction systems not yet available in wearable hearing aids have documented benefits of noise reduction on memory for speech processing for older adults.
CONCLUSIONS: This evidence supports the use of SMNR for adults and school-aged children when the aim is to improve listening comfort or reduce listening effort. Future research should test SMNR with infants and children who are younger than 5 years of age. Further development, testing, and clinical trials should be carried out on algorithms not yet available in wearable hearing aids. Testing higher cognitive level for speech processing and learning of novel sounds or words could show benefits of advanced signal processing features. These approaches should be expanded to other populations such as children and younger adults. Implications for rehabilitation The review provides a quick reference for students and clinicians regarding the efficacy and effectiveness of SMNR in wearable hearing aids. This information is useful during counseling session to build a realistic expectation among hearing aid users. Most studies in the adult population suggest that SMNR may provide some benefits to adult listeners in terms of listening comfort, acceptance of background noise, and release of cognitive load in a complex listening condition. However, it does not improve speech intelligibility. Studies that examined SMNR in the paediatric population suggest that SMNR may benefit older school-aged children, aged between 10 and 12 years old. The evidence supports the use of SMNR for adults and school-aged children when the aim is to improve listening comfort or reduce listening effort.

Matched MeSH terms: Noise
Fulltext Different bimodal neuromodulation settings reduce tinnitus symptoms in a large randomized trial

Conlon B, Hamilton C, Meade E, Leong SL, O Connor C, Langguth B, et al.

Sci Rep, 2022 Jun 30;12(1):10845.
PMID: 35773272 DOI: 10.1038/s41598-022-13875-x

More than 10% of the population suffers from tinnitus, which is a phantom auditory condition that is coded within the brain. A new neuromodulation approach to treat tinnitus has emerged that combines sound with electrical stimulation of somatosensory pathways, supported by multiple animal studies demonstrating that bimodal stimulation can elicit extensive neural plasticity within the auditory brain. More recently, in a large-scale clinical trial, bimodal neuromodulation combining sound and tongue stimulation drove significant reductions in tinnitus symptom severity during the first 6 weeks of treatment, followed by diminishing improvements during the second 6 weeks of treatment. The primary objective of the large-scale randomized and double-blinded study presented in this paper was to determine if background wideband noise as used in the previous clinical trial was necessary for bimodal treatment efficacy. An additional objective was to determine if adjusting the parameter settings after 6 weeks of treatment could overcome treatment habituation effects observed in the previous study. The primary endpoint at 6-weeks involved within-arm and between-arm comparisons for two treatment arms with different bimodal neuromodulation settings based on two widely used and validated outcome instruments, Tinnitus Handicap Inventory and Tinnitus Functional Index. Both treatment arms exhibited a statistically significant reduction in tinnitus symptoms during the first 6-weeks, which was further reduced significantly during the second 6-weeks by changing the parameter settings (Cohen's d effect size for full treatment period per arm and outcome measure ranged from - 0.7 to - 1.4). There were no significant differences between arms, in which tongue stimulation combined with only pure tones and without background wideband noise was sufficient to reduce tinnitus symptoms. These therapeutic effects were sustained up to 12 months after the treatment ended. The study included two additional exploratory arms, including one arm that presented only sound stimuli during the first 6 weeks of treatment and bimodal stimulation in the second 6 weeks of treatment. This arm revealed the criticality of combining tongue stimulation with sound for treatment efficacy. Overall, there were no treatment-related serious adverse events and a high compliance rate (83.8%) with 70.3% of participants indicating benefit. The discovery that adjusting stimulation parameters overcomes previously observed treatment habituation can be used to drive greater therapeutic effects and opens up new opportunities for optimizing stimuli and enhancing clinical outcomes for tinnitus patients with bimodal neuromodulation.

Matched MeSH terms: Noise
Accurate wavelet thresholding method for ECG signals

Yu K, Feng L, Chen Y, Wu M, Zhang Y, Zhu P, et al.

Comput Biol Med, 2024 Feb;169:107835.
PMID: 38096762 DOI: 10.1016/j.compbiomed.2023.107835

Current wavelet thresholding methods for cardiogram signals captured by flexible wearable sensors face a challenge in achieving both accurate thresholding and real-time signal denoising. This paper proposes a real-time accurate thresholding method based on signal estimation, specifically the normalized ACF, as an alternative to traditional noise estimation without the need for parameter fine-tuning and extensive data training. This method is experimentally validated using a variety of electrocardiogram (ECG) signals from different databases, each containing specific types of noise such as additive white Gaussian (AWG) noise, baseline wander noise, electrode motion noise, and muscle artifact noise. Although this method only slightly outperforms other methods in removing AWG noise in ECG signals, it far outperforms conventional methods in removing other real noise. This is attributed to the method's ability to accurately distinguish not only AWG noise that is significantly different spectrum of the ECG signal, but also real noise with similar spectra. In contrast, the conventional methods are effective only for AWG noise. In additional, this method improves the denoising visualization of the measured ECG signals and can be used to optimize other parameters of other wavelet methods to enhancing the denoised periodic signals, thereby improving diagnostic accuracy.

Matched MeSH terms: Signal-To-Noise Ratio
Fulltext Knowledge, attitude and practice of sawmill workers towards noise-induced hearing loss in kota bharu, kelantan

Rus RM, Daud A, Musa KI, Naing L

Malays J Med Sci, 2008 Oct;15(4):28-34.
PMID: 22589635

The purpose of this study was to determine the sawmill workers' knowledge, attitude and practice (KAP) in relation to noise-induced hearing loss (NIHL). A cross-sectional study was conducted involving 83 workers from 3 factories in Kota Bharu, Kelantan. Questionnaires were distributed to obtain the socio-demography, knowledge, attitude and practice level in relation to noise-induced hearing loss (NIHL). The weak areas identified in the knowledge section were treatment aspects (15.5%), signs and symptoms of NIHL (20.2%) and risk factors (31%). As for attitude; the prevention aspects were the lowest (25.3%), followed by risk taking attitude (26.2%), and causes of hearing loss (42.1%). Overall, the practice was not encouraging at all. It is important to have an education program to raise workers' awareness and to improve their attitude and practices towards noise-induced hearing loss.

Matched MeSH terms: Hearing Loss, Noise-Induced
The effectiveness of applying different permissible exposure limits in preserving the hearing threshold level: a systematic review

Sayapathi BS, Su AT, Koh D

J Occup Health, 2014;56(1):1-11.
PMID: 24270928

OBJECTIVES: A systematic review was conducted to identify the effectiveness of different permissible exposure limits in preserving the hearing threshold level. This review compared the limits of the US National Institute of Occupational Safety and Health with those of the US Occupational Safety and Health Administration. The prevalence of occupational noise-induced hearing loss is on an increasing trend globally. This review was performed to reduce the prevalence of noise-induced hearing loss.
METHODS: We searched 3 major databases, i.e., PubMed, Embase and Lippincott Williams & Wilkins Journals@Ovid, for studies published up until 1May 2013 without language restrictions. All study designs were included in this review. The studies were identified and retrieved by two independent authors.
RESULTS: Of 118 titles scanned, 14 duplicates were removed, and a total of 13 abstracts from all three databases were identified for full-text retrieval. From the full text, eight articles met the inclusion criteria for this systematic review. These articles showed acceptable quality based on our scoring system. Most of the studies indicated that temporary threshold shifts were much lower when subjects were exposed to a noise level of 85 dBA or lower.
CONCLUSIONS: There were more threshold shifts in subjects adopting 90 dBA compared with 85 dBA. These temporary threshold shifts may progress to permanent shifts over time. Action curtailing noise exposure among employees would be taken earlier on adoption of 85 dBA as the permissible exposure limit, and hence prevalence of noise-induced hearing loss may be reduced.

Matched MeSH terms: Hearing Loss, Noise-Induced/epidemiology; Hearing Loss, Noise-Induced/prevention & control*; Noise, Occupational/adverse effects*; Noise, Occupational/prevention & control
A study on compliance to hearing conservation programme among industries in Negeri Sembilan, Malaysia

Nor Saleha IT, Noor Hassim I

Ind Health, 2006 Oct;44(4):584-91.
PMID: 17085919

Noise is one of the hazards faced by workers. A cross-sectional study was conducted among industries in Negeri Sembilan with the objective to assess their compliance to Hearing Conservation Programme (HCP). The other objectives of this study were to determine the factors influencing it and to show the industries' compliance to each element of the programme. It was also to identify the association between compliance to HCP and the prevalence of hearing impairment and standard threshold shift. Data for this study were collected using questionnaires sent by mail and also the results of the latest audiometric tests. A total of 167 industries were analysed for this study. It was found that 41.3% of these industries fully complied to the programme. It was also found that the industries preferred to provide hearing protection device (92.8%) and least complied to noise control (61.1%). There were significant associations (p<0.05) between compliance and number of employees, status of ownership and the presence of officer in charge of hearing conservation programme. Having at least 150 employees actually raised the compliance to HCP in two folds (beta = 0.717, OR = 2.048, C.I 95% = 1.063 to 3.944). The prevalences of hearing impairment and standard threshold shift were 23.9% and 5.2% respectively. There was no significant association between the prevalence for hearing impairment and compliance to HCP. The prevalence for standard threshold shift was inversely related to compliance. This study showed that compliance percentage need to be improved as an effort to prevent the hearing problems among workers exposed to noise.

Matched MeSH terms: Hearing Loss, Noise-Induced/etiology; Hearing Loss, Noise-Induced/epidemiology; Hearing Loss, Noise-Induced/prevention & control*; Noise, Occupational/adverse effects*
Fulltext Hearing loss and contributing factors among airport workers in Malaysia

Nasir MH, Rampal KG

Med J Malaysia, 2012 Feb;67(1):81-6.
PMID: 22582554 MyJurnal

Sensorineural hearing loss is a common and important source of disability among the workers and often caused by occupational noise exposure. Aims of the study were to determine the prevalence and contributing factors of hearing loss among airport workers. A cross-sectional study was carried out at an airport in Malaysia. This study used stratified sampling method that involved 358 workers who were working in 3 different units between November 2008 and March 2009. Data for this study were collected by using questionnaires eliciting sociodemographic, occupational exposure history (previous and present), life-style including smoking habits and health-related data. Otoscopic and pure-tone audiometric tests were conducted for hearing assessment. Noise exposure status was categorize by using a noise logging dosimeter to obtain 8-hour Time-Weighted Average (TWA). Data was analyzed by using SPSS version 12.0.1 and EpiInfo 6.04. The prevalence of hearing loss was 33.5%. Age >40 years old (aOR 4.3, 95%CI 2.2-8.3) is the main risk factors for hearing loss followed by duration of noise exposure >5 years (aOR 2.5, 95%CI 1.4-4.7), smoking (aOR 2.1, 95%CI 1.2-3.4), duration of service >5 years (aOR 2.1, 95%CI 1.1-3.9), exposure to explosion (aOR 6.1, 95%CI 1.3-29.8), exposure to vibration (aOR 2.2, 95%CI 1.1-4.3) and working in engineering unit (aOR 5.9, 95%CI 1.1-30.9). The prevalence rate ratio of hearing loss for nonsmokers aged 40 years old and younger, smokers aged 40 years old and younger, non-smokers older than 40 years old and smokers older than 40 years old was 1.0, 1.7, 2.8 and 4.6 respectively. This result contributes towards better understanding of risk factors for hearing loss, which is relatively common among Malaysian workers.

Matched MeSH terms: Hearing Loss, Noise-Induced/etiology*; Hearing Loss, Noise-Induced/epidemiology
Screening of dental staff nurses for noise induced hearing loss

Daud MK, Noh NF, Sidek DS, Abd Rahman N, Abd Rani N, Zakaria MN

B-ENT, 2011;7(4):245-9.
PMID: 22338236

The effect of noise on employees of dental clinics is debatable. The purposes of this study were to determine the intensity and frequency components of dental instruments used by dental staff nurses and the prevalence of noise induced hearing loss.

Matched MeSH terms: Hearing Loss, Noise-Induced/diagnosis; Hearing Loss, Noise-Induced/epidemiology*
3 Tesla magnetic resonance imaging noise in standard head and neck sequence does not cause temporary threshold shift in high frequency

Lim EY, Tang IP, Peyman M, Ramli N, Narayanan P, Rajagopalan R

Eur Arch Otorhinolaryngol, 2015 Nov;272(11):3109-13.
PMID: 25205300 DOI: 10.1007/s00405-014-3232-y

High acoustic noise level is one of the unavoidable side effects of 3 T magnetic resonance imaging (MRI). A case of hearing loss after 3 T MRI has been reported in this institution and hence this study. The objective of this study was to determine whether temporary threshold shift (TTS) in high frequency hearing occurs in patients undergoing 3 T MRI scans of the head and neck. A total of 35 patients undergoing head and neck 3 T MRI for various clinical indications were tested with pure tone audiometry in different frequencies including high frequencies, before and after the MRI scan. Any threshold change from the recorded baseline of 10 dB was considered significant. All patients were fitted with foamed 3 M earplugs before the procedure following the safety guidelines for 3 T MRI. The mean time for MRI procedure was 1,672 s (range 1,040-2,810). The noise dose received by each patient amounted to an average of 3,906.29% (1,415-9,170%). The noise dose was derived from a normograph used by Occupational Noise Surveys. This was calculated using the nomograph of L eq, L EX, noise dose and time. There was no statistically significant difference between the hearing threshold before and after the MRI procedures for all the frequencies (paired t test, P > 0.05). For patients using 3 M foamed earplugs, noise level generated by 3 T MRI during routine clinical sequence did not cause any TTS in high frequency hearing.

Matched MeSH terms: Hearing Loss, Noise-Induced/etiology*; Noise*

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