Combined Effects Of Noise Research Articles

Model of Satellite Communication Channel Functioning under Conditions of Episodic Synchronization with Pulse Interference Flows

The article investigates the effect of pulse interference on information reception in conditions of episodic synchronization of frames of the physical level of a satellite communication channel with streams of radio pulses of unintended interference. An analytical model of the influence of pulse interference on the reception of information in a satellite communication channel under conditions of episodic synchronization of physical-level frames with pulse interference streams is proposed. Using the example of the DVB family of standards, the combined effect of noise and unintended impulse interference on the conditional error probabilities when receiving a synchro group, the service part of the header and the information part of the frame is shown. Estimates of the average number of frames of the physical level for the duration of the interval of episodic synchronization, the number of intervals of episodic synchronization and the proportion of elementary parcels in the frame exposed to interference, depending on the duration of the pulse interference, are given. It is shown that there are such relations between the duration of the interference pulse and the continuity of the sequence, in which the phenomenon of the episodic synchronization of physical-level frames with the flow of pulse interference has a significant impact on the functioning of the satellite communication channel. The dependences of the probability of erroneous reception of a frame of the physical level of a satellite communication channel on the signal-to-interference ratio at the fixed signal-to-noise ratio and on the duration of the interference pulse are obtained. It has been found that at high signal-to-noise ratios and the duration of the interference correlated with the duration of the service part of the frame, but significantly less than the duration of the frame, the probability of erroneous reception of the frame may be higher than at lower signal-to-noise ratios due to errors when receiving the service part of the frames.

Features of professional hearing loss with combined exposure to noise and vibration

For most modern industries, there is characteristic the simultaneous impact of noise with other factors aggravating its effect.
 The purpose of the study is to determine the features of occupational hearing loss in the combined effects 
 of noise and vibration.
 Materials and methods. A comparative assessment of the level of occupational risk and audiometric indicators was carried out in three groups of employees: 1st group (210 people) — is exposed to noise, 2nd group 
 (170 people) — to noise and local vibration, 3rd group (200 people) — to noise and general vibration.
 Results. In group 1 workers exposed to isolated noise, occupational hearing loss was diagnosed significantly less frequently compared to group 2 and 3 including workers exposed to combined noise and vibration 
 (7% vs. 14 and 13%, respectively, p < 0.05). Combined exposure to noise and vibration increases the risk of occupational hearing loss by 1.82–1.85 times (RR = 1.82–1.85; EF = 45–46%). Audiological features 
 of the lesion of the auditory analyzer have been revealed depending on the presence and nature of the affecting vibration, manifested by changes in hearing thresholds in certain frequency spectra and their combination. According to the data of speech audiometry, a violation of speech intelligibility with the presence of speech-tonal dissociation was revealed in workers of groups 2 and 3, indicating violations in the central department 
 of the auditory analyzer.
 Limitations of the study. The study is limited to the study of the features of occupational hearing loss in the combined effects of noise and vibration in mining workers according to audiometric indicators.
 Conclusion. The conducted studies have shown the need to develop individual programs for the preservation of hearing, taking into account the degree of risk and the identified features of the formation of occupational hearing loss. The topic of research on the effects of noise and vibration on hearing loss requires in-depth research, taking into account the intensity and duration of vibration exposure, the type of vibration generating equipment.

Noise-induced auditory damage affects hippocampus causing memory deficits in a model of early age-related hearing loss

Several studies identified noise-induced hearing loss (NIHL) as a risk factor for sensory aging and cognitive decline processes, including neurodegenerative diseases, such as dementia and age-related hearing loss (ARHL). Although the association between noise- and age-induced hearing impairment has been widely documented by epidemiological and experimental studies, the molecular mechanisms underlying this association are not fully understood as it is not known how these risk factors (aging and noise) can interact, affecting memory processes. We recently found that early noise exposure in an established animal model of ARHL (C57BL/6 mice) accelerates the onset of age-related cochlear dysfunctions. Here, we extended our previous data by investigating what happens in central brain structures (auditory cortex and hippocampus), to assess the relationship between hearing and memory impairment and the possible combined effect of noise and sensory aging on the cognitive domain. To this aim, we exposed juvenile C57BL/6 mice of 2 months of age to repeated noise sessions (60 min/day, pure tone of 100 dB SPL, 10 kHz, 10 consecutive days) and we monitored auditory threshold by measuring auditory brainstem responses (ABR), spatial working memory, by using the Y-maze test, and basal synaptic transmission by using ex vivo electrophysiological recordings, at different time points (1, 4 and 7 months after the onset of noise exposure, corresponding to 3, 6 and 9 months of age). We found that hearing loss, along with accelerated presbycusis onset, can induce persistent synaptic alterations in the auditory cortex. This was associated with decreased memory performance and oxidative-inflammatory injury in the hippocampus, the extra-auditory structure involved in memory processes. Collectively, our data confirm the critical relationship between auditory and memory circuits, suggesting that the combined detrimental effect of noise and sensory aging on hearing function can be considered a high-risk factor for both sensory and cognitive degenerative processes, given that early noise exposure accelerates presbycusis phenotype and induces hippocampal-dependent memory dysfunctions.

The combined effects of artificial light at night and anthropogenic noise on life history traits in ground crickets

AbstractUrbanization affects various biotic and abiotic conditions through the disturbance and modification of the environment by human activity. Anthropogenic noise and artificial light at night (ALAN) associated with urbanization have negative impacts on wildlife. However, few studies have focused on the combined effects of noise and ALAN, and the counter‐adaptation of urban individuals to environmental pollution. We examined the single and combined effects of ALAN and noise on life history traits, including developmental period, survival rate, egg diapause, the number of progeny, and body size, of the cricket Dianemobius nigrofasciatus. We examined whether urban individuals are adapted to these factors by a common garden experiment using the crickets of both urban and rural origin. Our findings revealed no combined effect of ALAN and noise on the life‐history traits of D. nigrofasciatus except on that of survival and progeny production. Both ALAN and noise alone delayed development and prevented egg diapause. Neither noise nor ALAN had a significant effect on body size. The survival rate of rural crickets was not affected by noise and ALAN, but there was a negative synergetic effect. However, there were no significant effects of ALAN, noise, or their combined effect on the survival rate of urban crickets. These results suggest that urban individuals exhibit adaptive evolution to these factors. The number of progeny was positively affected by noise and not affected by ALAN, while the combined effect negatively affected the progeny production. The results suggest that a combined effect of noise and ALAN on important factors for the cricket such as survival and reproduction.

The combined effects of noise and vibration stress on sex hormone levels, fertility capacity, and the protective role of cinnamon extract in rats: an experimental study

Due to the high prevalence of noise and vibration exposure in most industries, this study aimed to investigate the effects of simultaneous exposure to noise and vibration on sex hormone levels and fertility capacity in rats, as well as the protective effects of the hydroalcoholic extract of cinnamon. In this experimental study, 64 adult male rats were randomly divided into 8 groups, control, noise (N), cinnamon (C), noise + cinnamon (NC), vibration (V), vibration + cinnamon (VC), noise + vibration (NV) and groups Noise + Vibration + Cinnamon (NVC). Groups C, NC, VC and NVC received a 75 mg/kg dose of cinnamon extract by gavage. The rats of groups N and NC, V and VC and NV and NVC were each exposed to noise at 100 dB (700–5700 Hz), vibration acceleration of 1 m/s2 rms (frequency range of 4–8 Hz), and simultaneously exposed to vibration and noise for 8 hours continuously every night (23:00–7:00) for 50 consecutive nights. Next, a blood sample was taken from the lateral tail vein and the levels of LH, FSH and testosterone were measured with ELISA kits. Each male rat was caged with 3 female rats for one week. The pregnant rats were kept until all of the rat pups were born. Then the fertility capacity, the total number of births, the live births and the birth weight of the rat pups were analyzed with the software SPSS. In the N and NV groups, compared to the control group, a significant decrease in LH and testosterone levels, the number of births and the birth weight was observed (p < 0.05). A significant decrease in testosterone levels, number of births and birth weight was observed in Group V compared to the control group (p < 0.05). In addition, significant increases in LH, FSH and testosterone levels and in birth weight were observed in group C compared to the control group (p < 0.05). Significant increases in FSH and testosterone levels, birth weight, and the number of births were noted in the NVC group compared to the NV group (p < 0.05). Based on the results of this study, cinnamon extract could alleviate the destructive effects of noise and vibration (both individually and in combination) on levels of sex hormones (LH, FSH, and testosterone), the number of births, and birth weight.

Extrinsic stressors modulate resource evaluations: insights from territoriality under artificial noise

BackgroundCompetition is considered to rely on the value attributed to resources by animals, but the influence of extrinsic stressors on this value remains unexplored. Although natural or anthropogenic environmental stress often drives decreased competition, assumptions that this relies on resource devaluation are without formal evidence. According to theory, physiological or perceptual effects may influence contest behaviour directly, but motivational changes due to resource value are expected to manifest as behavioural adjustments only in interaction with attainment costs and resource benefits. Thus, we hypothesise that stressor-induced resource devaluations will impose greater effects when attainment costs are high, but not when resource benefits are higher. Noise may elicit such effects because it impacts the acoustic environment and imposes physiological and behavioural costs to animals. Therefore, we manipulated the acoustic environment using playbacks of artificial noise to test our hypotheses in the territorial male Siamese fighting fish, Betta splendens.ResultsCompared to a no-playback control, noise reduced defense motivation only when territory owners faced comparatively bigger opponents that impose greater injury costs, but not when territories also contained bubble nests that offer reproductive benefits. In turn, nest-size decreases were noted only after contests under noise treatment, but temporal nest-size changes relied on cross-contest variation in noise and comparative opponent size. Thus, the combined effects of noise are conditional on added attainment costs and offset by exceeding resource benefits.ConclusionOur findings provide support for the hypothesised modulation of resource value under extrinsic stress and suggest implications for competition under increasing anthropogenic activity.

Combined effects of noise and air temperature on human neurophysiological responses in a simulated indoor environment

The aim of the present study was to evaluate the combined effects of noise and air temperature on the human body neurophysiological responses. This study was conducted on 35 male students, who were exposed to four different air temperatures (18 °C, 22 °C, 26 °C, and 30 °C) and two noise levels (55 dBA and 75 dBA) in eight sessions in a simulated indoor environment. The mean values of accuracy and time of response to stimuli in N-back test as well as neurophysiological responses were measured. In the studied experiment configurations, with increasing air temperature and noise, the working memory and neurophysiological responses were disturbed. The results indicated the significant effect of noise on working memory, as compared with that of air temperature. The effects of air temperature on heart rate, respiratory rate as well as theta and alpha bands were more significant than the impact of noise. The combined effects of noise and air temperature were more significant than the influence of each of them alone. In the presence of high noise levels, the increase in air temperature did not worsen the response accuracy. However, in the presence of high noise level, the rise in air temperature aggravated the mean value of neurophysiological responses. Overall, noise has a greater effect on working memory, while the air temperature can disturb neurophysiological responses in a more profound way.

Combined effect of noise and hand-transmitted vibration on noise-induced hearing loss in the automobile manufacturing industry

Objective: To investigate the combined effect of noise and hand-transmitted vibration on noise-induced hearing loss (NIHL) in the automobile manufacturing industry. Methods: From September 2018 to January 2019, cluster sampling was used to select 998 workers in an automobile factory as study subjects, among whom 352 workers exposed to noise alone were enrolled as noise group, 342 workers exposed to noise and hand-transmitted vibration were enrolled as combined effect group, and 304 workers without exposure to occupational hazardous factors were enrolled as control group. A questionnaire survey and pure tone audiometry were performed for all study subjects. An analysis of variance was used for comparison of continuous data between groups, and the chi-square test was used for comparison of categorical data between groups; a ordinal polytomous logistic regression analysis was used to investigate the influencing factors for NIHL (with 0.05 as the inclusion criteria and 0.10 as the exclusion criteria for independent variables) . Results: There was a significant difference in L(Aeq, 8 h) between groups (P<0.05) ; the noise group and the combined effect group had a significantly higher L(Aeq, 8 h) than the control group (P<0.05) , while there was no significant difference in L(Aeq, 8 h) between the noise group and the combined effect group (P>0.05) . The control group had a significantly lower detection rate of hearing loss than the noise group and the combined effect group (P<0.0125) , and the combined effect group had a significantly higher detection rate of hearing loss than the noise group (P<0.0125) . The ordinal polytomous logistic regression analysis showed that after adjustment for confounding factors such as age, working years, sex, smoking, and drinking, both noise exposure and exposure to both noise and hand-transmitted vibration had an influence on workers' hearing (P<0.05) , and the workers exposed to both noise and hand-transmitted vibration had a higher risk of hearing loss than those exposed to noise alone. Conclusion: There may be a combined effect of noise and hand-transmitted vibration in the automobile manufacturing industry, which can increase the risk of NIHL in workers.

Histogram Based Clustering for Nonlinear Compensation in Long Reach Coherent Passive Optical Networks

In order to meet the increasing capacity requirements, network operators are extending their optical infrastructure closer to the end-user while making more efficient use of the resources. In this context, long reach passive optical networks (LR-PONs) are attracting increasing attention.Coherent LR-PONs based on high speed digital signal processors represent a high potential alternative because, alongside with the inherent mixing gain and the possibility of amplitude and phase diversity formats, they pave the way to compensate linear impairments in a more efficient way than in traditional direct detection systems. The performance of coherent LR-PONs is then limited by the combined effect of noise and nonlinear distortion. The noise is particularly critical in single channel systems where, in addition to the the elevated fibre loss, the splitting losses should be considered. In such systems, Kerr induced self-phase modulation emerges as the main limitation to the maximum capacity. In this work, we propose a novel clustering algorithm, denominated histogram based clustering (HBC), that employs the spatial density of the points of a 2D histogram to identify the borders of high density areas to classify nonlinearly distorted noisy constellations. Simulation results reveal that for a 100 km long LR-PON with a 1:64 splitting ratio, at optimum power levels, HBC presents a Q-factor 0.57 dB higher than maximum likelihood and 0.21 dB higher than k-means. In terms of nonlinear tolerance, at a BER of 2×10 − 3 , our method achieves a gain of ∼2.5 dB and ∼1.25 dB over maximum likelihood and k-means, respectively. Numerical results also show that the proposed method can operate over blocks as small as 2500 symbols.

The effects of combined exposure to noise and heat on human salivary cortisol and blood pressure

Purpose. Noise and heat are the most important physical hazardous agents that can affect physiological parameters. This study investigated the independent and combined effects of noise and heat exposure on human saliva cortisol and blood pressure. Methods. In this experimental study, 72 students were exposed to noise (at sound pressure levels of 45, 75, 85 and 95 dB(A)) and heat (at wet bulb globe temperatures [WBGTs] of 22, 29 and 34 °C) for 30 min. Samples of saliva and blood pressure were taken before and after each independent and combined exposure. Results. The results revealed that the average saliva cortisol and blood pressure in male and female subjects increased significantly after independent exposure to noise at 95 dB(A) and a WBGT of 34 °C. The combined exposure to noise and heat increased saliva cortisol and blood pressure, which was statistically significant for three combinations of 95 dB(A) at 34 °C, 95 dB(A) at 29 °C and 85 dB(A) at 34 °C. Conclusions. Combined exposure to noise and heat could affect saliva cortisol and blood pressure in both male and female groups. Further studies are recommended to capture other combinations of physical hazardous agents, especially in the field.

Proteomes analysis reveals the involvement of autophagy in AD-like neuropathology induced by noise exposure and ApoE4

BackgroundNoise is one of the most important environmental health hazards for humans. Environmental noise or apolipoprotein ε4 (ApoE4) can cause typical Alzheimer's disease (AD)-like pathological changes, which is characterized by progressive cognitive decline and neurodegenerative lesions. Gene–environment interactions may accelerate cognitive decline and increase AD risk. However, there is limited experimental evidence regarding the underlying mechanisms of noise-ApoE4 interactions and AD, which may be closely related to AD development. MethodsIn this study, we investigated the combined effects of chronic noise exposure and the ApoE4 gene activation on hippocampus by using proteomics and differentially expressed proteins were found through performed gene ontology function and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis. In addition, we assessed the changes in adult hippocampal neurogenesis and potential underlying mechanism for AD-like neuropathology. ResultsRelative to control rats, combined exposure of noise and ApoE4 synergistically increased the characteristic pathological amyloid β-protein of AD-like neuropathology changes in hippocampus. The research identifies a total of 4147 proteins and 15 differentially expressed proteins in hippocampus. Furthermore, comparison of several of the diverse key pathways studied (e.g., PI3K/AKT, insulin, calpain-CDK5, and mammalian target of rapamycin (mTOR) signaling pathways) help to articulate the different mechanisms involved in combined effects of noise and ApoE4 on AD-like pathology. We verified four selected proteins, namely, eukaryotic translation elongation factor 1 epsilon 1, glycine amidinotransferase, nucleoredoxin, and tuberous sclerosis 1 proteins. Validation data shows significant effects of chronic noise and ApoE4 on the expression of four selected proteins, eukaryotic translation elongation factor 1 epsilon 1, glycine amidinotransferase, nucleoredoxin, and tuberous sclerosis 1 proteins, and mTOR and autophagy-related proteins, which share significant interaction effect of chronic noise and ApoE4. ConclusionGene-environment interactions between chronic noise and ApoE4 activate the mTOR signaling, decrease autophagy, and facilitate AD-like changes in the hippocampus. Thus, our findings may help elucidate the role of gene–environment interactions in AD development.

Two-stage Deep Learning for Noisy-reverberant Speech Enhancement.

In real-world situations, speech reaching our ears is commonly corrupted by both room reverberation and background noise. These distortions are detrimental to speech intelligibility and quality, and also pose a serious problem to many speech-related applications, including automatic speech and speaker recognition. In order to deal with the combined effects of noise and reverberation, we propose a two-stage strategy to enhance corrupted speech, where denoising and dereverberation are conducted sequentially using deep neural networks. In addition, we design a new objective function that incorporates clean phase during model training to better estimate spectral magnitudes, which would in turn yield better phase estimates when combined with iterative phase reconstruction. The two-stage model is then jointly trained to optimize the proposed objective function. Systematic evaluations and comparisons show that the proposed algorithm improves objective metrics of speech intelligibility and quality substantially, and significantly outperforms previous one-stage enhancement systems.

Automated Subjective Assessment of Speech Intelligibility in Various Listening Modes

In this paper, the results of automated subjective assessment of Ukrainian speech intelligibility are presented. Speech monosyllables of the consonant-vowel-consonant (CVC) type were listened in two modes: through headphones and through acoustic monitors. The assessment was carried out with the help of specially developed software that allowed automating of articulation tests. Speech listening was done for four situations: pure language; speech distorted by noise; speech distorted by reverberation; speech distorted by the combined effect of noise and reverberation. In the first case, speech monosyllables of 3 articulation tables were listened, each of which contained 50 monosyllables. In the second case, speech distorted by the additive noise with the signal-to-noise ratios (SNR) varied in the range ‑15…+10 dB was listened. In this case, models of white, pink and brown noises were used, the masking properties of which are rather well-studied. In the third case, the reverberant speech for reverberation times in the range 0.3…2.7 s was modeled by convolution of pure speech signals with room impulse responces (RIRs) of various rooms, and in the fourth case the joint action of pink noise and reverberation was considered. It turned out that the masking ability of white noise exceeds one for brown noise for SNR less than minus 5 dB, which is not entirely consistent with preliminary predictive estimates. In addition, it turned out that listening to speech distorted by noise through acoustic monitors could lead to a significant increase in the speech intelligibility, compared to the case of listening through headphones. The analysis of possible causes of abnormal increase in speech intelligibility has been carried out. Early reflections, presence of two loudspeakers, binaural listening, psychophysical features of listeners, as well as peculiarities of software and articulatory testing organization were considered as possible reasons of the phenomenon. After correction of the software and some features of articulation tests it turned out that the results of the speech intelligibility estimation almost coincide when listening to the signals through the headphones and through acoustic monitors, if the distance between the listener and acoustic monitors does not exceed 0.6-0.8 meters. At the same time, these corrections did not differ in the behavior of the dependencies of speech intelligibility on the SNR for small (less minus 5 dB) SNR values The general conclusion may be that listening to speech signals distorted by noise and reverberation interferences, performed with the application of the proposed automated system of articulation tests, indicates the performance and high quality of the developed system.Ref. 13, fig. 7.

Road traffic noise, air pollution, and risk of dementia – results from the Betula project

BackgroundThere is growing evidence for a negative impact of traffic-related air pollution on risk of dementia. However, the contribution of noise exposure to this association has been rarely examined. ObjectiveWe aimed to investigate the individual and combined effect of noise and air pollution on risk of dementia. MethodsData on dementia incidence over a 15 year period was obtained from the Betula project, a longitudinal study on health and ageing. Estimates of annual mean levels of nitrogen oxides (NOx) at the participants’ residential address were obtained using a land-use regression model. Modelled data provided road traffic noise levels (Leq. 24 h) at the participants’ residential address at baseline. Cox proportional hazard regression was used to calculate hazard ratios (HR). ResultsOf 1721 participants at baseline, 302 developed dementia during the follow up period. Exposure to noise levels (Leq. 24 h) > 55 dB had no significant effect on dementia risk (HR 0.95; CI: 0.57, 1.57). Residing in the two highest quartiles of NOx exposure was associated with an increased risk of dementia. The risk associated with NOx was not modified by adjusting for noise. Moreover, we found no significant interaction effects between NOx and road traffic noise on dementia risk. ConclusionWe found no evidence that exposure to road traffic noise, either independently or in combination with traffic air pollution, was associated with risk of dementia in our study area. Our results suggest that pollution should be considered the main component in the association between traffic related exposures and dementia.

Subjective Evaluation of the Speech Intelligibility on the Background of Noise and Reverberation

In this paper, the results of speech intelligibility subjective assessment of Ukrainian speech monosyllabic sound combinations against background noise and reverberation through articulation tests are presented. The evaluation was carried out with the help of specially developed software that allowed automating and thus greatly facilitating and accelerating the procedure of articulation tests. Special text and sound tables of the Ukrainian speech monosyllables of the consonant-vowel-consonant (CVC) type were developed for the tests. The recordings of pure signals were made in the muffled room of the Acoustics and Acoustoelectronics Department of the National Technical University of Ukraine "Igor Sikorsky Kyiv Polytechnic Institute". The recording was performed at a frequency of 22050 Hz and a bit depth of 16 bits. Speech monosyllables were read using a verbal environment. Listening was done for four situations: pure language; speech distorted by noise; speech distorted by reverberation; speech distorted by the combined effect of noise and reverberation. In the first case, speech monosyllables of 3 articulation tables were listened, each of which contained 50 monosyllables. In the second case, speech distorted by the additive noise with the signal-to-noise ratios minus 10 dB, 0 dB and plus 10 dB was listened. In this case, models of white, pink and brown noises were used, the masking property of which is rather well-studied. In the third case, the reverberant speech for reverberation times from 0.3 to 2.7 s was modeled by convolution of pure speech signals with impulse characteristics of various rooms, and in the fourth case the joint action of pink noise and reverberation was considered. It turned out that the masking ability of white noise exceeds one for brown noise for signal-to-noise ratios (SNR) less than minus 5 dB, which is not entirely consistent with previous preliminary predictive estimates. Signals listening had been made by two ways, namely through the headphones and by means of acoustic monitors. The SNR varied in the range ‑10…+10 dB, and the reverberation time varied in the range 0.3…2.7 s. In addition, it turned out that listening to speech distorted by noise through acoustic monitors could lead to a significant increase in the intelligibility of speech, compared to the case of listening through headphones. With a signal-to-noise ratio of minus 10 dB, the values of speech intelligibility scores increased from 0.1-0.3 to 0.85-0.93. Similar results were obtained for the reverberation action: the speech intelligibility increased from 0.65 to 0.94 for the reverberation time of 2.7 s. This speech intelligibility growth can be explained, firstly, by the action of early reflections. Secondly, usage of two loudspeakers as sound sources and also binaural listening can be also considered as reasons of speech intelligibility increase. Nevertheless, these reasons for increasing the intelligibility of speech are hardly the only ones. Therefore, it is necessary to further study the causes of the revealed significant increase in speech intelligibility. Among such reasons can be both features of the developed automated system of articulation tests, and features of the psychophysical state of listeners.Ref. 13, fig. 5.

Combined Effects of Noise and Reverberation on Sound Localization for Listeners With Normal Hearing and Bilateral Cochlear Implants.

This study examined the individual and combined effects of noise and reverberation on the ability of listeners with normal hearing (NH) and with bilateral cochlear implants (BCIs) to localize speech. Six adults with BCIs and 10 with NH participated. All subjects completed a virtual localization test in quiet and at 0-, -4-, and -8-dB signal-to-noise ratios (SNRs) in simulated anechoic and reverberant (0.2-, 0.6-, and 0.9-s RT60) environments. BCI users were also tested at +8- and +4-dB SNR. A 3-word phrase was presented at 70 dB SPL from 9 simulated locations in the frontal horizontal plane (±90°), with the noise source at 0°. BCIs users had significantly poorer localization than listeners with NH in all conditions. BCI users' performance started to decrease at a higher SNR (+4 dB) and shorter RT60 (0.2 s) than listeners with NH (-4 dB and 0.6 s). The combination of noise and reverberation began to degrade localization of BCI users at a higher SNR and a shorter RT60 than listeners with NH. The clear effect of noise and reverberation on the performance of BCI users provides information that should be useful for refining cochlear implant processing strategies and developing cochlear implant rehabilitation plans to optimize binaural benefit for BCI users in everyday listening situations.

Combined effect of noise and room acoustics on vocal effort in simulated classrooms.

This work investigated the relationships between room acoustics, background noise level, and vocal effort of a speaker in simulated classrooms of various volumes. Under simulated acoustic environments, talkers adjusted their vocal effort linearly with the voice support, i.e., the degree of amplification offered by the room to the voice of a speaker, at his own ears. The slope of this relationship, called the room effect, of -0.24 dB/dB was significant only in the case of the highest noise levels of 62 dB. The vocal comfort for the speaker, however, was found to be more closely related to noise annoyance than to room reverberance.

Noise-induced hearing loss and combined noise and vibration exposure.

While there is a wide body of literature addressing noise-induced hearing loss (NIHL) and hand-arm vibration syndrome (HAVS) independently, relatively few studies have considered the combined effects of noise and vibration. These studies have suggested an increased risk of NIHL in workers with vibration white finger (VWF), though the relationship remains poorly understood. To determine whether hearing impairment is worse in noise-exposed workers with VWF than in workers with similar noise exposures but without VWF. The Quebec National Institute of Public Health audiometric database was used in conjunction with work-related accident and occupational diseases data from the Quebec workers' compensation board to analyse differences in audiometry results between vibration-exposed workers in the mining and forestry industries and the overall source population, and between mining and forestry workers with documented VWF and those without VWF. The International Organization for Standardization (ISO) 7029 standards were used to calculate hearing loss not attributable to age. 15751 vibration-exposed workers were identified in an overall source population of 59339. Workers with VWF (n = 96) had significantly worse hearing at every frequency studied (500, 1000, 2000 4000 Hz) compared with other mining and forestry workers without VWF. This study confirms previous findings of greater hearing loss at higher frequencies in workers with VWF, but also found a significant difference in hearing loss at low frequencies. It therefore supports the association between combined noise and hand-arm vibration (HAV) exposure and NIHL.

Impact of combined effect of noise and heat on blood pressure: a meta-analysis

目的 探讨噪声与高温联合暴露对工人血压的影响.方法 分别检索1990至2012年在《维普中文科技期刊数据库》《中国知网》和《万方数字化期刊数据库》等公开发表的原始文献,检索主题词和关键词为噪声、高温、联合暴露、血压、心血管、健康效应,检索语种为中文.按剔除与纳入标准分类整理,进行Meta分析,探讨噪声与高温联合暴露对工人血压的影响,并作敏感性分析.结果 15篇原始文献被纳入分析,累计对照组4 530例,联合暴露组3 558例.联合暴露组发生血压异常风险是对照组的4.02(95％CI:3.75～4.30)倍,高温暴露组发生血压异常风险为3.30(95％CI:2.36～4.23)倍,噪声暴露组发生血压异常风险为3.01(95％CI:2.40～3.61)倍.结论 噪声与高温联合暴露对工人血压的影响显著。

How do Spatial Scale, Noise, and Reference Data affect Empirical Estimates of Error in ASAR-Derived 1 km Resolution Soil Moisture?

The performance of the advanced synthetic aperture radar (ASAR) global mode (GM) surface soil moisture (SSM) data was studied over Australia by means of two widely used bivariate measures, the root-mean-square error (RMSE) and the Pearson correlation coefficient (R). By computing RMSE and at multiple spatial scales and for different data combinations, we assessed how, and at which scales, the spatial sampling error, noise, and the choice of the reference data impact on RMSE and . The results reveal large changes in RMSE and with continental average values of 8% and 18% for the RMSE of relative soil moisture saturation and between 0.4 and 0.7 for depending on the spatial scale of aggregation and the choice of reference data. The combined effect of noise and spatial sampling error accounted for a 79% RMSE increase at 1 km and predominated over the error due to the choise of the reference data also at 5 km scale. The effect of noise on RMSE strongly diminished at spatial scales ≥2 km. By contrast, the impact of uncertainties in the reference data was larger on than on RMSE. This highlights the better potential of to estimate the benefit of observations prior to data assimilation. Based on our results, it is further suggested that a potential way for an improved ASAR GM SSM error assessment is to: 1) aggregate the data to ≥2 km resolution to minimize the noise; 2) subtract the spatial sampling error within the coarse resolution footprint; and 3) remove the reference uncertainty using advanced techniques such as triple collocation.