Displaying publications 121 - 140 of 189 in total

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  1. 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
  2. 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
  3. Sim KS, Kiani MA, Nia ME, Tso CP
    J Microsc, 2014 Jan;253(1):1-11.
    PMID: 24164248 DOI: 10.1111/jmi.12089
    A new technique based on cubic spline interpolation with Savitzky-Golay noise reduction filtering is designed to estimate signal-to-noise ratio of scanning electron microscopy (SEM) images. This approach is found to present better result when compared with two existing techniques: nearest neighbourhood and first-order interpolation. When applied to evaluate the quality of SEM images, noise can be eliminated efficiently with optimal choice of scan rate from real-time SEM images, without generating corruption or increasing scanning time.
    Matched MeSH terms: Signal-To-Noise Ratio*
  4. Sulaiman AH, Husain R, Seluakumaran K
    Eur Arch Otorhinolaryngol, 2014 Jun;271(6):1463-70.
    PMID: 23812554 DOI: 10.1007/s00405-013-2612-z
    Although sound exposure from personal listening devices (PLDs) could potentially lead to noise-induced hearing loss (NIHL), the actual hearing risk associated with the use of these devices is still unclear. In this study, early hearing effects related to PLD usage were evaluated in 35 young adult PLD users (listening for >1 h/day, at >50% of the maximum volume setting of their devices) and their age- and sex-matched controls using a combination of conventional and extended high-frequency audiometry as well as transient-evoked otoacoustic emission (TEOAE) and distortion product of otoacoustic emission (DPOAE) measurements. The mean listening duration of the PLD users was 2.7 ± 1.0 h/day while their estimated average listening volume was 81.3 ± 9.0 dBA (free-field corrected). Typical signs of NIHL were not detected in the audiogram of PLD users and their audiometric thresholds at most of the conventional test frequencies (0.25-8 kHz) were comparable with those obtained from controls. However, compared with the controls, mean hearing thresholds of PLD users at many of the extended high-frequencies (9-16 kHz) were significantly higher. In addition, TEOAE and DPOAE amplitudes in users were reduced compared with controls. The deterioration of extended high-frequency thresholds and the decrease in DPOAE amplitudes were more evident in the users' right ears. These results indicate the presence of an early stage of hearing damage in the PLD user group. Preventive steps should be taken as the initial hearing damage in these users could eventually progress into permanent NIHL after many years of PLD use.
    Matched MeSH terms: Hearing Loss, Noise-Induced/diagnosis*
  5. Bin WS, Richardson S, Yeow PH
    Int J Occup Saf Ergon, 2010;16(3):345-56.
    PMID: 20828490
    The study aimed to conduct an ergonomic intervention on a conventional line (CL) in a semiconductor factory in Malaysia, an industrially developing country (IDC), to improve workers' occupational health and safety (OHS). Low-cost and simple (LCS) ergonomics methods were used (suitable for IDCs), e.g., subjective assessment, direct observation, use of archival data and assessment of noise. It was found that workers were facing noise irritation, neck and back pains and headache in the various processes in the CL. LCS ergonomic interventions to rectify the problems included installing noise insulating covers, providing earplugs, installing elevated platforms, slanting visual display terminals and installing extra exhaust fans. The interventions cost less than 3 000 USD but they significantly improved workers' OHS, which directly correlated with an improvement in working conditions and job satisfaction. The findings are useful in solving OHS problems in electronics industries in IDCs as they share similar manufacturing processes, problems and limitations.
    Matched MeSH terms: Noise, Occupational/prevention & control
  6. Sulaiman AH, Seluakumaran K, Husain R
    Public Health, 2013 Aug;127(8):710-5.
    PMID: 23474376 DOI: 10.1016/j.puhe.2013.01.007
    To investigate listening habits and hearing risks associated with the use of personal listening devices among urban high school students in Malaysia.
    Matched MeSH terms: Hearing Loss, Noise-Induced/etiology*
  7. Maisarah SZ, Said H
    Med J Malaysia, 1993 Sep;48(3):280-5.
    PMID: 8183139
    A total of 524 industrial workers were studied. They consisted of 442 noise exposed and 82 non-noise exposed workers. The purpose was to compare the prevalence of sensori-neural hearing loss among the noise exposed and the non-noise exposed workers, to study their knowledge on the hazard of noise to hearing and the workers' attitude towards the hearing protection devices. The prevalence of sensori-neural hearing loss was significantly higher among the noise exposed workers, i.e., 83% versus 31.7% (p < 0.01). However, the prevalence of hearing impairment was much lower for both groups, being 30.1% for the noise exposed and 3.7% for the non-noise exposed group. Although hearing protection devices were provided to 80.5% of the workers, only 5.1% were wearing them regularly. The possibility of developing hearing loss due to exposure to excessive noise was only known by 35.5% of the noise exposed workers. This awareness was found to have a positive correlation with the workers' compliance to the hearing protection devices. Our findings highlight the need for workers to be educated on the hazards of excessive noise exposure to hearing.
    Matched MeSH terms: Hearing Loss, Noise-Induced/epidemiology*
  8. Mukari SZMS, Yusof Y, Ishak WS, Maamor N, Chellapan K, Dzulkifli MA
    Braz J Otorhinolaryngol, 2018 12 10;86(2):149-156.
    PMID: 30558985 DOI: 10.1016/j.bjorl.2018.10.010
    INTRODUCTION: Hearing acuity, central auditory processing and cognition contribute to the speech recognition difficulty experienced by older adults. Therefore, quantifying the contribution of these factors on speech recognition problem is important in order to formulate a holistic and effective rehabilitation.

    OBJECTIVE: To examine the relative contributions of auditory functioning and cognition status to speech recognition in quiet and in noise.

    METHODS: We measured speech recognition in quiet and in composite noise using the Malay Hearing in noise test on 72 native Malay speakers (60-82 years) older adults with normal to mild hearing loss. Auditory function included pure tone audiogram, gaps-in-noise, and dichotic digit tests. Cognitive function was assessed using the Malay Montreal cognitive assessment.

    RESULTS: Linear regression analyses using backward elimination technique revealed that had the better ear four frequency average (0.5-4kHz) (4FA), high frequency average and Malay Montreal cognitive assessment attributed to speech perception in quiet (total r2=0.499). On the other hand, high frequency average, Malay Montreal cognitive assessment and dichotic digit tests contributed significantly to speech recognition in noise (total r2=0.307). Whereas the better ear high frequency average primarily measured the speech recognition in quiet, the speech recognition in noise was mainly measured by cognitive function.

    CONCLUSIONS: These findings highlight the fact that besides hearing sensitivity, cognition plays an important role in speech recognition ability among older adults, especially in noisy environments. Therefore, in addition to hearing aids, rehabilitation, which trains cognition, may have a role in improving speech recognition in noise ability of older adults.

    Matched MeSH terms: Noise*
  9. Usmani S, Rasheed R, Al Kandari F
    J Nucl Med Technol, 2020 Jun;48(2):181-183.
    PMID: 32111663 DOI: 10.2967/jnmt.119.235986
    Textitis is a new term used to refer to the degenerative-strain osteoarthritis that comes from excessive use of a smart phone. 18F-NaF is increasingly used in diagnosing skeletal pain that is not identified on radiographs. We report a case of a 26-y-old woman with left breast cancer referred for 18F-NaF PET/CT, who was complaining of right thumb and wrist pain. Findings were negative for bone secondaries. Dedicated hands views were acquired on a positron emission mammography scanner and showed focal uptake at the first carpometacarpal and second metacarpophalangeal joints. On the basis of the strong history, the findings were likely due to active arthritic changes caused by repetitive strain injury from excessive text messaging.
    Matched MeSH terms: Signal-To-Noise Ratio*
  10. Rahma MS, Mustafa BE, Razali A, Shamsuddin N, Althunibat OY
    Noise Health, 2013 Nov-Dec;15(67):375-8.
    PMID: 24231415 DOI: 10.4103/1463-1741.121223
    Several epidemiologic studies have reported that exposure to noise is associated with cardiovascular disease. The increased body weight is often associated with metabolic as well as increased blood pressure. The aim of this study is to investigate the correlation between the elevation of blood pressure and serum leptin hormones due to the effects of noise in the work place. A total of 80 volunteer males where included in this study with an age range between of 20 and 45 years, they were divided in two groups equally, the 1 st group were exposed to noise in the workplace while the 2 nd group were not. The individual noise exposure was determined by using a sound level meter. The range of noise was 80-100 dBA. Body Mass Index was also taken for each individual by a standard measure, blood pressure was measured by OMRON sphygmomanometer and serum leptin was measured through venous blood sample analysis enzyme linked immunosorbent assay. Spearman rank order correlation was used to examine the correlations between Blood pressure value (Systolic, Diastolic) and Leptin. All the relationships between parameters showed a positive correlation. Systolic and diastolic blood pressure values had a significant correlation to leptin hormone level in comparison to the control. There was a significant relation between leptin and blood pressure. leptin effects on the sympathetic nervous system may provide a partial explanation. Therefore, Leptin might have diverse cardiovascular actions.
    Matched MeSH terms: Noise, Occupational/adverse effects*
  11. Ali A, Hussain RM, Dom NC, Md Rashid RI
    Noise Health, 2018 4 21;20(93):53-59.
    PMID: 29676296 DOI: 10.4103/nah.NAH_14_17
    Introduction: Motorcycle riders with noise sensitivity (NS) may suffer from degraded health-related quality of life (HRQOL) because they are exposed to acute noise levels on a daily basis.

    Materials and Methods: This study was aimed to identify the relationship between NS and HRQOL among young motorcycle riders (undergraduate university students) aged between 19 and 25 years (n = 301) through a cross-sectional questionnaire-based study, that is, Weinstein noise sensitivity scale and the World Health Organization Quality of Life. The effects of NS on HRQOL were assessed based on gender, the years of motorcycle driving experience, and noise sensitive among groups using one-way analysis of variances with an alpha value of 0.05.

    Results: The results showed no significant difference in NS between males and females. On the other hand, motorcycle driving experience for <4 years displayed a higher tendency toward NS. Moreover, a significantly (P = 0.004) decreasing trend among low, moderate, and high NS with their respective HRQOL was observed, while a high NS showed significantly (P = 0.015) lower scores on the social domain of the quality of life.

    Conclusion: The overall premise of the study has statistical significance and shows that individuals with high NS tend to have degraded HRQOL compared to individuals with low NS. Furthermore, in-depth studies are required from the other demographical background of participants to investigate the motorcyclist's NS and HRQOL as an integral requirement for the rider's safety and health.

    Matched MeSH terms: Noise, Transportation/adverse effects*
  12. Quar TK, Soli SD, Chan YF, Ishak WS, Abdul Wahat NH
    Int J Audiol, 2017 02;56(2):92-98.
    PMID: 27686009 DOI: 10.1080/14992027.2016.1210828
    OBJECTIVE: This study was conducted to evaluate the speech perception of Malaysian Chinese adults using the Taiwanese Mandarin HINT (MHINT-T) and the Malay HINT (MyHINT).

    DESIGN: The MHINT-T and the MyHINT were presented in quiet and noise (front, right and left) conditions under headphones. Results for the two tests were compared with each other and with the norms for each test.

    STUDY SAMPLE: Malaysian Chinese native speakers of Mandarin (N = 58), 18-31 years of age with normal hearing.

    RESULTS: On average, subjects demonstrated poorer speech perception ability than the normative samples for these tests. Repeated measures ANOVA showed that speech reception thresholds (SRTs) were slightly poorer on the MHINT-T than on the MyHINT for all test conditions. However, normalized SRTs were poorer by 0.6 standard deviations for MyHINT as compared with MHINT-T.

    CONCLUSIONS: MyHINT and MHINT-T can be used as norm-referenced speech perception measures for Mandarin-speaking Chinese in Malaysia.

    Matched MeSH terms: Noise/adverse effects*
  13. Muhammad Izani Mohd Shiyuti, Irfan Mohamad, Dinsuhaimi Sidek
    MyJurnal
    The effect of loud noise to the army personnel is often identified when hearing loss had already developed. Acoustic trauma during shooting training can also lead to acute changes in the ear which is shown on otoscopic examination. This study was undertaken to determine the effectiveness of hearing protective device (earplug) on the prevalence of external ear changes amongst military personnel during shooting. This is a prospective cross sectional study that was conducted among 76 military personnel, who were divided into two groups: those with and without earplugs during shooting. Each participant underwent 3 otoscopic examinations: (a) pre-shooting, (b) immediate post-shooting (within 48 hours) and (c) 2 weeks after shooting. A total of 78 army personnel who were scheduled to undergo shooting training were otoscopically examined. Eighty three percent of them did not wear earplugs before. The percentage of inflammation of external auditory canal and tympanic membrane dullness increased tremendously among subjects from non–earplug group less than 48 hours post-shooting. Assessment after 2 weeks showed improvement in around 30% of the subjects. Loud noise has become an occupational hazard not only to the inner ear but it also predisposes the external and middle ear structures to some form of injury. Although improvement is seen after some period, a protective device such as an earplug should be recommended and the usage should be reinforced among the army personnel involved in shooting.
    Matched MeSH terms: Hearing Loss, Noise-Induced; Noise
  14. Manakandan SK, Rosnah I, Mohd Ridhuan J, Priya R
    Med J Malaysia, 2017 08;72(4):228-235.
    PMID: 28889134 MyJurnal
    BACKGROUND: The most crucial step in forming a set of survey questionnaire is deciding the appropriate items in a construct. Retaining irrelevant items and removing important items will certainly mislead the direction of a particular study. This article demonstrates Fuzzy Delphi method as one of the scientific analysis technique to consolidate consensus agreement within a panel of experts pertaining to each item's appropriateness. This method reduces the ambiguity, diversity, and discrepancy of the opinions among the experts hence enhances the quality of the selected items. The main purpose of this study was to obtain experts' consensus on the suitability of the preselected items on the questionnaire.

    METHODS: The panel consists of sixteen experts from the Occupational and Environmental Health Unit of Ministry of Health, Vector-borne Disease Control Unit of Ministry of Health and Occupational and Safety Health Unit of both public and private universities. A set of questionnaires related to noise and chemical exposure were compiled based on the literature search. There was a total of six constructs with 60 items in which three constructs for knowledge, attitude, and practice of noise exposure and three constructs for knowledge, attitude, and practice of chemical exposure. The validation process replicated recent Fuzzy Delphi method that using a concept of Triangular Fuzzy Numbers and Defuzzification process.

    RESULTS: A 100% response rate was obtained from all the sixteen experts with an average Likert scoring of four to five. Post FDM analysis, the first prerequisite was fulfilled with a threshold value (d) ≤ 0.2, hence all the six constructs were accepted. For the second prerequisite, three items (21%) from noise-attitude construct and four items (40%) from chemical-practice construct had expert consensus lesser than 75%, which giving rise to about 12% from the total items in the questionnaire. The third prerequisite was used to rank the items within the constructs by calculating the average fuzzy numbers. The seven items which did not fulfill the second prerequisite similarly had lower ranks during the analysis, therefore those items were discarded from the final draft.

    CONCLUSION: Post FDM analysis, the experts' consensus on the suitability of the pre-selected items on the questionnaire set were obtained, hence it is now ready for further construct validation process.

    Matched MeSH terms: Noise, Occupational/adverse effects
  15. Saffree Jeffree M, Ismail N, Awang Lukman K
    J Occup Health, 2016 Sep 30;58(5):434-443.
    PMID: 27488035
    INTRODUCTION: Hearing impairment remains the main occupational health problem in the manufacturing industry, and its contributing factors have not been well controlled.

    METHODS: Unmatched case control and comparative studies were carried out among fertilizer factory workers in Sarawak with the aim of determining contributing factors for hearing impairment. Respondents consisted of 49 cases that were diagnosed from 2005 to 2008 with 98 controls from the same work places. Chi-square test and Mann-Whitney test were used in a univariate analysis to determine the association between hearing impairment and the contributing risks being studied.

    RESULTS: The results of the univariate analysis showed that hearing impairment was significantly (p<0.05) associated with older age, lower education level, high smoking dose, high occupational daily noise dose, longer duration of service, infrequent used of hearing protection device (HPD), and low perception of sound on HPD usage. Multivariate logistic regression of hearing impairment after controlling for age found the following five variables: occupational daily noise dose ≥50% (OR 3.48, 95% CI 1.36-8.89), ≥15 years of services (OR 2.92, 95% CI 1.16-7.33), infrequent use of HPD (OR 2.79, 95% CI 1.15-6.77), low perception of sound on HPD (POR 2.77, 95% CI 1.09-6.97), and smoking more than 20 packs per year (OR 4.71, 95% CI 1.13-19.68).

    DISCUSSION: In conclusion, high occupational noise exposure level, longer duration of service, low perception of sound on HPD, infrequent used of HPD, and smoking more than 20 packs per year were the contributing factors to hearing impairment, and appropriate intervention measures should be proposed and taken into considerations.

    Matched MeSH terms: Hearing Loss, Noise-Induced/etiology*; Hearing Loss, Noise-Induced/prevention & control; Noise, Occupational/adverse effects*
  16. Faisal A, Parveen S, Badsha S, Sarwar H, Reza AW
    J Med Syst, 2013 Jun;37(3):9938.
    PMID: 23504472 DOI: 10.1007/s10916-013-9938-3
    An improved and efficient method is presented in this paper to achieve a better trade-off between noise removal and edge preservation, thereby detecting the tumor region of MRI brain images automatically. Compass operator has been used in the fourth order Partial Differential Equation (PDE) based denoising technique to preserve the anatomically significant information at the edges. A new morphological technique is also introduced for stripping skull region from the brain images, which consequently leading to the process of detecting tumor accurately. Finally, automatic seeded region growing segmentation based on an improved single seed point selection algorithm is applied to detect the tumor. The method is tested on publicly available MRI brain images and it gives an average PSNR (Peak Signal to Noise Ratio) of 36.49. The obtained results also show detection accuracy of 99.46%, which is a significant improvement than that of the existing results.
    Matched MeSH terms: Signal-To-Noise Ratio
  17. Mori M, Sagara K, Arai K, Nakatani N, Ohira S, Toda K, et al.
    J Chromatogr A, 2016 Jan 29;1431:131-7.
    PMID: 26755416 DOI: 10.1016/j.chroma.2015.12.064
    Selective separation and sensitive detection of dissolved silicon and boron (DSi and DB) in aqueous solution was achieved by combining an electrodialytic ion isolation device (EID) as a salt remover, an ion-exclusion chromatography (IEC) column, and a corona charged aerosol detector (CCAD) in sequence. DSi and DB were separated by IEC on the H(+)-form of a cation exchange resin column using pure water eluent. DSi and DB were detected after IEC separation by the CCAD with much greater sensitivity than by conductimetric detection. The five-channel EID, which consisted of anion and cation acceptors, cathode and anode isolators, and a sample channel, removed salt from the sample prior to the IEC-CCAD. DSi and DB were scarcely attracted to the anion accepter in the EID and passed almost quantitatively through the sample channel. Thus, the coupled EID-IEC-CCAD device can isolate DSi and DB from artificial seawater and hot spring water by efficiently removing high concentrations of Cl(-) and SO4(2-) (e.g., 98% and 80% at 0.10molL(-1) each, respectively). The detection limits at a signal-to-noise ratio of 3 were 0.52μmolL(-1) for DSi and 7.1μmolL(-1) for DB. The relative standard deviations (RSD, n=5) of peak areas were 0.12% for DSi and 4.3% for DB.
    Matched MeSH terms: Signal-To-Noise Ratio
  18. Al-Gumaei YA, Noordin KA, Reza AW, Dimyati K
    PLoS One, 2015;10(8):e0135137.
    PMID: 26258522 DOI: 10.1371/journal.pone.0135137
    Spectrum scarcity is a major challenge in wireless communications systems requiring efficient usage and utilization. Cognitive radio network (CRN) is found as a promising technique to solve this problem of spectrum scarcity. It allows licensed and unlicensed users to share the same licensed spectrum band. Interference resulting from cognitive radios (CRs) has undesirable effects on quality of service (QoS) of both licensed and unlicensed systems where it causes degradation in received signal-to-noise ratio (SIR) of users. Power control is one of the most important techniques that can be used to mitigate interference and guarantee QoS in both systems. In this paper, we develop a new approach of a distributed power control for CRN based on utility and pricing. QoS of CR user is presented as a utility function via pricing and a distributed power control as a non-cooperative game in which users maximize their net utility (utility-price). We define the price as a real function of transmit power to increase pricing charge of the farthest CR users. We prove that the power control game proposed in this study has Nash Equilibrium as well as it is unique. The obtained results show that the proposed power control algorithm based on a new utility function has a significant reduction in transmit power consumption and high improvement in speed of convergence.
    Matched MeSH terms: Signal-To-Noise Ratio
  19. Billings CJ, Grush LD, Maamor N
    Physiol Rep, 2017 Nov;5(20).
    PMID: 29051305 DOI: 10.14814/phy2.13464
    The effects of background noise on speech-evoked cortical auditory evoked potentials (CAEPs) can provide insight into the physiology of the auditory system. The purpose of this study was to determine background noise effects on neural coding of different phonemes within a syllable. CAEPs were recorded from 15 young normal-hearing adults in response to speech signals /s/, /ɑ/, and /sɑ/. Signals were presented at varying signal-to-noise ratios (SNRs). The effects of SNR and context (in isolation or within syllable) were analyzed for both phonemes. For all three stimuli, latencies generally decreased and amplitudes generally increased as SNR improved, and context effects were not present; however, the amplitude of the /ɑ/ response was the exception, showing no SNR effect and a significant context effect. Differential coding of /s/ and /ɑ/ likely result from level and timing differences. Neural refractoriness may result in the lack of a robust SNR effect on amplitude in the syllable context. The stable amplitude across SNRs in response to the vowel in /sɑ/ suggests the combined effects of (1) acoustic characteristics of the syllable and noise at poor SNRs and (2) refractory effects resulting from phoneme timing at good SNRs. Results provide insights into the coding of multiple-onset speech syllables in varying levels of background noise and, together with behavioral measures, may help to improve our understanding of speech-perception-in-noise difficulties.
    Matched MeSH terms: Signal-To-Noise Ratio
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