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Fulltext The association between subcortical and cortical fMRI and lifetime noise exposure in listeners with normal hearing thresholds

Dewey RS, Francis ST, Guest H, Prendergast G, Millman RE, Plack CJ, et al.

Neuroimage, 2020 01 01;204:116239.
PMID: 31586673 DOI: 10.1016/j.neuroimage.2019.116239

In animal models, exposure to high noise levels can cause permanent damage to hair-cell synapses (cochlear synaptopathy) for high-threshold auditory nerve fibers without affecting sensitivity to quiet sounds. This has been confirmed in several mammalian species, but the hypothesis that lifetime noise exposure affects auditory function in humans with normal audiometric thresholds remains unconfirmed and current evidence from human electrophysiology is contradictory. Here we report the auditory brainstem response (ABR), and both transient (stimulus onset and offset) and sustained functional magnetic resonance imaging (fMRI) responses throughout the human central auditory pathway across lifetime noise exposure. Healthy young individuals aged 25-40 years were recruited into high (n = 32) and low (n = 30) lifetime noise exposure groups, stratified for age, and balanced for audiometric threshold up to 16 kHz fMRI demonstrated robust broadband noise-related activity throughout the auditory pathway (cochlear nucleus, superior olivary complex, nucleus of the lateral lemniscus, inferior colliculus, medial geniculate body and auditory cortex). fMRI responses in the auditory pathway to broadband noise onset were significantly enhanced in the high noise exposure group relative to the low exposure group, differences in sustained fMRI responses did not reach significance, and no significant group differences were found in the click-evoked ABR. Exploratory analyses found no significant relationships between the neural responses and self-reported tinnitus or reduced sound-level tolerance (symptoms associated with synaptopathy). In summary, although a small effect, these fMRI results suggest that lifetime noise exposure may be associated with central hyperactivity in young adults with normal hearing thresholds.

Matched MeSH terms: Noise/adverse effects*
Fulltext The Noise Exposure Structured Interview (NESI): An Instrument for the Comprehensive Estimation of Lifetime Noise Exposure

Guest H, Dewey RS, Plack CJ, Couth S, Prendergast G, Bakay W, et al.

Trends Hear, 2018;22:2331216518803213.
PMID: 30295145 DOI: 10.1177/2331216518803213

Lifetime noise exposure is generally quantified by self-report. The accuracy of retrospective self-report is limited by respondent recall but is also bound to be influenced by reporting procedures. Such procedures are of variable quality in current measures of lifetime noise exposure, and off-the-shelf instruments are not readily available. The Noise Exposure Structured Interview (NESI) represents an attempt to draw together some of the stronger elements of existing procedures and to provide solutions to their outstanding limitations. Reporting is not restricted to prespecified exposure activities and instead encompasses all activities that the respondent has experienced as noisy (defined based on sound level estimated from vocal effort). Changing exposure habits over time are reported by dividing the lifespan into discrete periods in which exposure habits were approximately stable, with life milestones used to aid recall. Exposure duration, sound level, and use of hearing protection are reported for each life period separately. Simple-to-follow methods are provided for the estimation of free-field sound level, the sound level emitted by personal listening devices, and the attenuation provided by hearing protective equipment. An energy-based means of combining the resulting data is supplied, along with a primarily energy-based method for incorporating firearm-noise exposure. Finally, the NESI acknowledges the need of some users to tailor the procedures; this flexibility is afforded, and reasonable modifications are described. Competency needs of new users are addressed through detailed interview instructions (including troubleshooting tips) and a demonstration video. Limited evaluation data are available, and future efforts at evaluation are proposed.

Matched MeSH terms: Hearing Loss, Noise-Induced/diagnosis*; Hearing Loss, Noise-Induced/epidemiology*; Noise, Occupational/adverse effects*
The Malay hearing in noise test

Quar TK, Mukari SZ, Abdul Wahab NA, Abdul Razak R, Omar M, Maamor N

Int J Audiol, 2008 Jun;47(6):379-80.
PMID: 18569117 DOI: 10.1080/14992020801886796
Matched MeSH terms: Noise*
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
Textitis as Seen on 18F-NaF Imaging Using an Ultra-High-Resolution Positron Emission Mammography Scanner

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*
Fulltext Temporal anticipation under cognitive stress

Suppiah, Pathmanathan K., Mohamad Razali Abdullah

Movement Health & Exercise, 2012;1(1):61-73.
MyJurnal

The ability to produce performances at highest level under physically and emotionally demanding conditions underline the worth of a sportsperson. These stressful conditions places demands on the cognitive resources of the sportsperson; especially in anticipatory actions that require the allocation of cognitive resources. This study investigated the effects of cognitive stress on the temporal anticipation of a timing motor task. A repeated measures design was applied with two independent variables; cognitive stress and levels of difficulty, which included easy, intermediate and difficult. Study participants were 18 male and 18 female undergraduates of the Physical Education programme of Universiti Putra Malaysia. The experimental task involved performing a timing motor task across the three levels of difficulty, under two conditions as follows: (i) without cognitive stress, and (ii) under cognitive stress. Cognitive stress was induced via the continuous subtraction of two from a two-digit number. Participants performed the task individually and the sequence of the experimental task was counter-balanced. A two-way within subject ANOVA was
performed to ascertain the effects of cognitive stress on the temporal anticipation of the timing motor task. Data yielded significant difference in means for the stress main effect [Λ = .64, F (1.35) = 19.89, p < 0.05]; and the task main effect [Λ = .84, F (2, 34) = 3.35, p < 0.05]. Post hoc comparisons produced a significant difference in the means of the performance of the timing motor task at all three levels of difficulty. Data showed that cognitive stress had an effect on the temporal anticipation of the timing motor task. These results are explained from attentional and the neuromotor noise perspectives. It was concluded that the significant difference in the performance of the experimental task was due to the competition for intentional resources and the decrease of the signal to noise ratio due to cognitive stress.

Matched MeSH terms: Noise; Signal-To-Noise Ratio
Fulltext Target detection in forward scattering radar

Mohamed Khalaf alla Hassan Mohamed, Raja Syamsul Azmir Raja Abdullah, Rasid, M.F.A.

Pertanika Journal of Science & Technology, 2009;17(2):-.
MyJurnal

This paper analyses electromagnetic signal scattered from the target crossing the Forward Scattering
Radar (FSR) system baseline. The aim of the analysis was to extract the Doppler signal of a target under the influence of high ground clutter and noise interference. The extraction was used for the
automatic target detection (ATD) in the FSR system. Two extraction methods, namely Hilbert Transform and Wavelet Technique, were analyzed. The detection using the Hilbert Transform is only applicable for some conditions; however, the detection using the Wavelet Technique is more robust to any clutter and noise level. From 55 sets of signal, only 4% of false alarm was detected or occurred when the Wavelet Technique was applied as a detection scheme. Two sets of field experimentation were carried out and the target’s signal under the influence of high clutter had successfully been detected using the proposed method.

Matched MeSH terms: Noise
Fulltext Tamper localization and lossless recovery watermarking scheme with ROI segmentation and multilevel authentication

Liew SC, Liew SW, Zain JM

J Digit Imaging, 2013 Apr;26(2):316-25.
PMID: 22555905 DOI: 10.1007/s10278-012-9484-4

Tamper localization and recovery watermarking scheme can be used to detect manipulation and recover tampered images. In this paper, a tamper localization and lossless recovery scheme that used region of interest (ROI) segmentation and multilevel authentication was proposed. The watermarked images had a high average peak signal-to-noise ratio of 48.7 dB and the results showed that tampering was successfully localized and tampered area was exactly recovered. The usage of ROI segmentation and multilevel authentication had significantly reduced the time taken by approximately 50 % for the tamper localization and recovery processing.

Matched MeSH terms: Signal-To-Noise Ratio
Fulltext T1 and T2 Characteristics of Agarose Gel Phantom with different Gadolinium Oxide Concentration as Relaxation Modifier

Azhar, N. A. A., Tee, H. S., Yee, Y. Y., Awang, M. N. A., Abdul Manan, H., Yusoff, A. N.

Physics and Technology in Medicine, 2020;1(1):27-37.
MyJurnal

Many studies have been carried out to produce magnetic resonance imaging (MRI) phantoms as alternative to water phantom. Among the important properties of a phantom are the T1 and T2 relaxation times. The objective of this study is to investigate the T1 and T2 characteristics of the agarose gel phantoms with different relaxation modifier (gadolinium (III) oxide, Gd2O3) concentrations or [Gd2O3]. Six agarose gel phantoms were prepared with different [Gd2O3]. The T1 (fixed echo time (TE) and different repetition time (TR)) and T2 (fixed TR and different TE) measurements on all phantoms were conducted using the 3-T MRI system via spin echo (SE) and turbo spin echo (TSE) sequences, respectively. The signal-to-noise ratio (SNR) of all phantoms was calculated using Image-J software by implementing the region of interest (ROI) analysis. The SNR against TR and SNR against TE curves were fitted to the exponential equations for saturation, T1 and T2 determination. For every phantom, T1 curve demonstrated that the SNR increased exponentially with increasing TR, while T2 curves showed that the SNR decreased exponentially with increasing TE. Gd2O3 was found to successfully act as the relaxation modifier for the T1 but not the T2 curves. The T1 curve started to show saturated SNR (SNRo) and increasing SNRo for TR > 1000 ms and [Gd2O3] = 0.005 g/ml or higher. These behaviours are explained based on the dipole-dipole interaction that increases in phantoms with higher [Gd2O3], thus shortening the T1 relaxation. However, a systematic change in the T2 parameters with increasing [Gd2O3] was not observed. While Gd2O3 has significant effects on T1 relaxation parameters, the T2 relaxation parameters were minimally affected. With a shorter T1, the Gd2O3 added agarose gel can potentially be used as test phantom in fast imaging sequence, e.g. gradient echo pulse sequences.

Matched MeSH terms: Signal-To-Noise Ratio
Fulltext Susceptibility to Residual Inhibition Is Associated With Hearing Loss and Tinnitus Chronicity

Hu S, Anschuetz L, Hall DA, Caversaccio M, Wimmer W

Trends Hear, 2021 3 6;25:2331216520986303.
PMID: 33663298 DOI: 10.1177/2331216520986303

Residual inhibition, that is, the temporary suppression of tinnitus loudness after acoustic stimulation, is a frequently observed phenomenon that may have prognostic value for clinical applications. However, it is unclear in which subjects residual inhibition is more likely and how stable the effect of inhibition is over multiple repetitions. The primary aim of this work was to evaluate the effect of hearing loss and tinnitus chronicity on residual inhibition susceptibility. The secondary aim was to investigate the short-term repeatability of residual inhibition. Residual inhibition was assessed in 74 tinnitus subjects with 60-second narrow-band noise stimuli in 10 consecutive trials. The subjects were assigned to groups according to their depth of suppression (substantial residual inhibition vs. comparator group). In addition, a categorization in normal hearing and hearing loss groups, related to the degree of hearing loss at the frequency corresponding to the tinnitus pitch, was made. Logistic regression was used to identify factors associated with susceptibility to residual inhibition. Repeatability of residual inhibition was assessed using mixed-effects ordinal regression including poststimulus time and repetitions as factors. Tinnitus chronicity was not associated with residual inhibition for subjects with hearing loss, while a statistically significant negative association between tinnitus chronicity and residual inhibition susceptibility was observed in normal hearing subjects (odds ratio: 0.63; p = .0076). Moreover, repeated states of suppression can be stably induced, reinforcing the use of residual inhibition for within-subject comparison studies.

Matched MeSH terms: Noise
Fulltext Subspace-based technique for speckle noise reduction in ultrasound images

Yahya N, Kamel NS, Malik AS

Biomed Eng Online, 2014;13(1):154.
PMID: 25421914 DOI: 10.1186/1475-925X-13-154

Ultrasound imaging is a very essential technique in medical diagnosis due to its being safe, economical and non-invasive nature. Despite its popularity, the US images, however, are corrupted with speckle noise, which reduces US images qualities, hampering image interpretation and processing stage. Hence, there are many efforts made by researches to formulate various despeckling methods for speckle reduction in US images.

Matched MeSH terms: Signal-To-Noise Ratio*
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
Speckle Noise Diffusion in Knee Articular Cartilage Ultrasound Images

Shoaib MA, Hossain MB, Hum YC, Chuah JH, Mohd Salim MI, Lai KW

Curr Med Imaging, 2020;16(6):739-751.
PMID: 32723246 DOI: 10.2174/1573405615666190903143330

BACKGROUND: Ultrasound (US) imaging can be a convenient and reliable substitute for magnetic resonance imaging in the investigation or screening of articular cartilage injury. However, US images suffer from two main impediments, i.e., low contrast ratio and presence of speckle noise.
AIMS: A variation of anisotropic diffusion is proposed that can reduce speckle noise without compromising the image quality of the edges and other important details.
METHODS: For this technique, four gradient thresholds were adopted instead of one. A new diffusivity function that preserves the edge of the resultant image is also proposed. To automatically terminate the iterative procedures, the Mean Absolute Error as its stopping criterion was implemented.
RESULTS: Numerical results obtained by simulations unanimously indicate that the proposed method outperforms conventional speckle reduction techniques. Nevertheless, this preliminary study has been conducted based on a small number of asymptomatic subjects.
CONCLUSION: Future work must investigate the feasibility of this method in a large cohort and its clinical validity through testing subjects with a symptomatic cartilage injury.

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
Simultaneous analysis of silicon and boron dissolved in water by combination of electrodialytic salt removal and ion-exclusion chromatography with corona charged aerosol detection

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
Signal-to-noise ratio estimation on SEM images using cubic spline interpolation with Savitzky-Golay smoothing

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*
Fulltext Serum leptin and corticosterone levels after exposure to noise stress in rats

Chandralekha G, Jeganathan R, Viswanathan, Charan JC

Malays J Med Sci, 2005 Jan;12(1):51-6.
PMID: 22605947

Even though extensive studies have been conducted on the effect of noise exposure on hearing apparatus / auditory system, information on the effect of noise on the other body functions is sparse. The present study examined the effect of exposure of albino rats to acute and chronic noise stress on two important interlaced endocrine levels. In acute experiments the animals were exposed to 120 dB noise for a duration of 1, 2, 3 hrs. In chronic experiments the animals were exposed to noise for one hour daily for 30, 60 and 90 days. Plasma corticosterone and leptin levels were measured in these animals. There was significant elevation in the levels of corticosterone and leptin after exposure to noise stress. The elevation in corticosterone level after noise stress is in agreement with earlier reports. So noise acts like a stressor and elevates the secretion of the corticosterone, the stress hormone and leptin, the product of the ob gene there is an elevation in leptin levels after noise stress.

Matched MeSH terms: Noise
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*
Fulltext SOA-based multi-wavelength source

Harun, S.W., Sulaiman, A.H., Ahmad, H.

ASM Science Journal, 2009;3(1):27-30.
MyJurnal

We demonstrate a multi-wavelength light source using a semiconductor optical amplifier (SOA) in conjunction with an array waveguide grating (AWG). The experimental results showed more than 20 channels with a wavelength separation of 0.8 nm and an optical signal-to-noise ratio of more than 10 dB under room temperature. The channels operated at the wavelength region from 1530.4 nm to 1548.6 nm, which corresponded to AWG filtering wavelengths with SOA drive current of 350 mA. The proposed light source had the advantages of a simple and compact structure, multi-wavelength operation and the system could be upgraded to generate more wavelengths.

Matched MeSH terms: Signal-To-Noise Ratio
Fulltext SNR improvements in self-heterodyne detection technique for laser linewidth measurements

Manimaran, R., Abdul-Rashid, H.A.

ASM Science Journal, 2008;2(2):133-137.
MyJurnal

This paper proposes a signal-to-noise-ratio (SNR) improvement by using an external phase modulator that allowed flexible control of the spectrum amplitude by varying the modulation index for linewidth measurements. Compared with the conventional self-heterodyne detection technique, the results obtained in this study showed an SNR improvement as high as 10 dB. This 10 dB improvement in SNR could help to reduce the usage of a particular length of a single mode fibre (normally about 50 Km) when measuring a linewidth in the region of 10 kHz.

Matched MeSH terms: Noise; Signal-To-Noise Ratio

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