Auditory Recognition of Words-in-Noise in Normal Hearing and Mild-to-Severe Sensorineural Hearing Loss with Different Configurations

Background and Aim: Sensorineural Hearing Loss (SNHL) reduces audibility and causes distortion, which result in difficulty with speech processing, especially in noisy environments. One of the new speech-in-noise tests is the Words-in-Noise (WIN) test. This study aimed to further investigate the Signal-to-Noise Ratio 50% (SNR-50) in subjects with mild to severe SNHL and different configurations using the Persian version of the WIN test compared to normal-hearing people. Methods: This cross-sectional study was conducted on 54 patients with SNHL aged 17–75 years and 49 normal-hearing people aged 20–48 years. The auditory recognition in the presence of multi-talker babble noise was evaluated by the Persian version of the WIN test (named ARWIN). Results: The mean SNR-50 in the normal-hearing group was 2.56±1.2 dB, which increased significantly in subgroups with mild (10.13±4.8 dB), moderate (14.51±4.7 dB) and moderate-to-severe (16.61±4.3 dB) SNHL (p<0.001). Conclusion: People with SNHL need more SNR by nearly 4–6 times than the normalhearing group for recognition of monosyllabic Persian words in the presence of multi-talker babble noise

Effect of Pleasantness and Unpleasantness of Music on the Acceptable Noise Level

Background and Aim: Music can be a favorite, annoying, or even a distracting noise. It is known that the processing of brain hemispheres is affected by the pleasantness/unpleasantness of music, which could be utilized as a signal or noise in auditory neuroscience. By using the Acceptable Noise Level (ANL) test, which is the quantification of noise tolerance while listening to a running speech, we investigated whether the pleasantness/unpleasantness of music affects the ANL results under monotic-listening and dichotic-listening conditions. Methods: Based on the subjective scale scores, pleasant and unpleasant music (10 songs) were selected as alternatives to babble noise or running speech for testing 50 subjects for seven monotic and dichotic listening conditions. Results: While pleasant music changed the ANL significantly under monotic listening conditions, the higher level of babble noise was tolerated, and both characteristics of music pleasantness and unpleasantness changed ANL significantly for various dichotic conditions. The range of the ANL for dichotic conditions is wider than that for monotic conditions. Conclusion: Music can affect the ANL in terms of pleasantness and unpleasantness for both monotic and dichotic listening conditions, with a greater effect on dichotic conditions, indicating the role of hemispheric specification in emotional music processing

The Effects of Hearing Aid Digital Noise Reduction and Directionality on Acceptable Noise Level

Objectives Two main digital signal processing technologies inside the modern hearing aid to provide the best conditions for hearing aid users are directionality (DIR) and digital noise reduction (DNR) algorithms. There are various possible settings for these algorithms. The present study evaluates the effects of various DIR and DNR conditions (both separately and in combination) on listening comfort among hearing aid users. Methods In 18 participants who received hearing aid fitting services from the Rehabilitation School of Shahid Beheshti University of Medical Sciences regularly, we applied acceptable noise level (ANL) as our subjective measure of listening comfort. We evaluated both of these under six different hearing aid conditions: omnidirectional-baseline, omnidirectional-broadband DNR, omnidirectional-multichannel DNR, directional, directional-broadband DNR, and directional-multichannel DNR. Results The ANL results ranged from −3 dB to 14 dB in all conditions. The results show, among all conditions, both the omnidirectional-baseline condition and the omnidirectional-broadband DNR condition are the worst conditions for listening in noise. The DIR always reduces the amount of noise that patients received during testing. The DNR algorithm does not improve listening in noise significantly when compared with the DIR algorithms. Although both DNR and DIR algorithms yielded a lower ANL, the DIR algorithm was more effective than the DNR. Conclusion The DIR and DNR technologies provide listening comfort in the presence of noise. Thus, user benefit depends on how the digital signal processing settings inside the hearing aid are adjusted

Human Umbilical Cord Mesenchymal Stem Cells-Derived Exosomes Can Alleviate the Proctitis Model Through TLR4/NF-Κb Pathway

Background: Proctitis is a significant concern of inflammatory bowel diseases, especially ulcerative colitis. Exosomes are a new method for treating many diseases by their immunosuppressive and tissue-repairing potential. Here, we tried Mesenchymal stem cells (MSCs)-derived Exosomes for treating the proctitis model of rats. Materials and Methods: Rats were assigned into four groups: sham, control group, rectal, and intraperitoneal exosome injection. The proctitis model was induced by rectal administration of 4% acetic acid. The exosome was derived from human MSCs isolated from human umbilical cords. After seven days, rectum samples were assessed for histopathological, IHC, and PCR analysis. Results: The histopathologic scores, collagen deposition, and the expression of NF-κB, TLR4, TNFα, IL-6, and TGFβ were decreased in intraperitoneal exosome compared to controls. The result was not promising for the rectal administration of exosomes. Conclusion: Exosomes can suppress the inflammatory response in the proctitis model and improve the rectum's healing process. Exosomes can inhabit the NF-κB/TLR4 pathway and downstream pro-inflammatory cytokines. This study implicates the therapeutic benefits of exomes in treating proctitis

Global age-sex-specific fertility, mortality, healthy life expectancy (HALE), and population estimates in 204 countries and territories, 1950-2019 : a comprehensive demographic analysis for the Global Burden of Disease Study 2019

Background: Accurate and up-to-date assessment of demographic metrics is crucial for understanding a wide range of social, economic, and public health issues that affect populations worldwide. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 produced updated and comprehensive demographic assessments of the key indicators of fertility, mortality, migration, and population for 204 countries and territories and selected subnational locations from 1950 to 2019. Methods: 8078 country-years of vital registration and sample registration data, 938 surveys, 349 censuses, and 238 other sources were identified and used to estimate age-specific fertility. Spatiotemporal Gaussian process regression (ST-GPR) was used to generate age-specific fertility rates for 5-year age groups between ages 15 and 49 years. With extensions to age groups 10–14 and 50–54 years, the total fertility rate (TFR) was then aggregated using the estimated age-specific fertility between ages 10 and 54 years. 7417 sources were used for under-5 mortality estimation and 7355 for adult mortality. ST-GPR was used to synthesise data sources after correction for known biases. Adult mortality was measured as the probability of death between ages 15 and 60 years based on vital registration, sample registration, and sibling histories, and was also estimated using ST-GPR. HIV-free life tables were then estimated using estimates of under-5 and adult mortality rates using a relational model life table system created for GBD, which closely tracks observed age-specific mortality rates from complete vital registration when available. Independent estimates of HIV-specific mortality generated by an epidemiological analysis of HIV prevalence surveys and antenatal clinic serosurveillance and other sources were incorporated into the estimates in countries with large epidemics. Annual and single-year age estimates of net migration and population for each country and territory were generated using a Bayesian hierarchical cohort component model that analysed estimated age-specific fertility and mortality rates along with 1250 censuses and 747 population registry years. We classified location-years into seven categories on the basis of the natural rate of increase in population (calculated by subtracting the crude death rate from the crude birth rate) and the net migration rate. We computed healthy life expectancy (HALE) using years lived with disability (YLDs) per capita, life tables, and standard demographic methods. Uncertainty was propagated throughout the demographic estimation process, including fertility, mortality, and population, with 1000 draw-level estimates produced for each metric. Findings: The global TFR decreased from 2·72 (95% uncertainty interval [UI] 2·66–2·79) in 2000 to 2·31 (2·17–2·46) in 2019. Global annual livebirths increased from 134·5 million (131·5–137·8) in 2000 to a peak of 139·6 million (133·0–146·9) in 2016. Global livebirths then declined to 135·3 million (127·2–144·1) in 2019. Of the 204 countries and territories included in this study, in 2019, 102 had a TFR lower than 2·1, which is considered a good approximation of replacement-level fertility. All countries in sub-Saharan Africa had TFRs above replacement level in 2019 and accounted for 27·1% (95% UI 26·4–27·8) of global livebirths. Global life expectancy at birth increased from 67·2 years (95% UI 66·8–67·6) in 2000 to 73·5 years (72·8–74·3) in 2019. The total number of deaths increased from 50·7 million (49·5–51·9) in 2000 to 56·5 million (53·7–59·2) in 2019. Under-5 deaths declined from 9·6 million (9·1–10·3) in 2000 to 5·0 million (4·3–6·0) in 2019. Global population increased by 25·7%, from 6·2 billion (6·0–6·3) in 2000 to 7·7 billion (7·5–8·0) in 2019. In 2019, 34 countries had negative natural rates of increase; in 17 of these, the population declined because immigration was not sufficient to counteract the negative rate of decline. Globally, HALE increased from 58·6 years (56·1–60·8) in 2000 to 63·5 years (60·8–66·1) in 2019. HALE increased in 202 of 204 countries and territories between 2000 and 2019

Global burden of 369 diseases and injuries in 204 countries and territories, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019

Background: In an era of shifting global agendas and expanded emphasis on non-communicable diseases and injuries along with communicable diseases, sound evidence on trends by cause at the national level is essential. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) provides a systematic scientific assessment of published, publicly available, and contributed data on incidence, prevalence, and mortality for a mutually exclusive and collectively exhaustive list of diseases and injuries. Methods: GBD estimates incidence, prevalence, mortality, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs) due to 369 diseases and injuries, for two sexes, and for 204 countries and territories. Input data were extracted from censuses, household surveys, civil registration and vital statistics, disease registries, health service use, air pollution monitors, satellite imaging, disease notifications, and other sources. Cause-specific death rates and cause fractions were calculated using the Cause of Death Ensemble model and spatiotemporal Gaussian process regression. Cause-specific deaths were adjusted to match the total all-cause deaths calculated as part of the GBD population, fertility, and mortality estimates. Deaths were multiplied by standard life expectancy at each age to calculate YLLs. A Bayesian meta-regression modelling tool, DisMod-MR 2.1, was used to ensure consistency between incidence, prevalence, remission, excess mortality, and cause-specific mortality for most causes. Prevalence estimates were multiplied by disability weights for mutually exclusive sequelae of diseases and injuries to calculate YLDs. We considered results in the context of the Socio-demographic Index (SDI), a composite indicator of income per capita, years of schooling, and fertility rate in females younger than 25 years. Uncertainty intervals (UIs) were generated for every metric using the 25th and 975th ordered 1000 draw values of the posterior distribution. Findings: Global health has steadily improved over the past 30 years as measured by age-standardised DALY rates. After taking into account population growth and ageing, the absolute number of DALYs has remained stable. Since 2010, the pace of decline in global age-standardised DALY rates has accelerated in age groups younger than 50 years compared with the 1990–2010 time period, with the greatest annualised rate of decline occurring in the 0–9-year age group. Six infectious diseases were among the top ten causes of DALYs in children younger than 10 years in 2019: lower respiratory infections (ranked second), diarrhoeal diseases (third), malaria (fifth), meningitis (sixth), whooping cough (ninth), and sexually transmitted infections (which, in this age group, is fully accounted for by congenital syphilis; ranked tenth). In adolescents aged 10–24 years, three injury causes were among the top causes of DALYs: road injuries (ranked first), self-harm (third), and interpersonal violence (fifth). Five of the causes that were in the top ten for ages 10–24 years were also in the top ten in the 25–49-year age group: road injuries (ranked first), HIV/AIDS (second), low back pain (fourth), headache disorders (fifth), and depressive disorders (sixth). In 2019, ischaemic heart disease and stroke were the top-ranked causes of DALYs in both the 50–74-year and 75-years-and-older age groups. Since 1990, there has been a marked shift towards a greater proportion of burden due to YLDs from non-communicable diseases and injuries. In 2019, there were 11 countries where non-communicable disease and injury YLDs constituted more than half of all disease burden. Decreases in age-standardised DALY rates have accelerated over the past decade in countries at the lower end of the SDI range, while improvements have started to stagnate or even reverse in countries with higher SDI. Interpretation: As disability becomes an increasingly large component of disease burden and a larger component of health expenditure, greater research and developm nt investment is needed to identify new, more effective intervention strategies. With a rapidly ageing global population, the demands on health services to deal with disabling outcomes, which increase with age, will require policy makers to anticipate these changes. The mix of universal and more geographically specific influences on health reinforces the need for regular reporting on population health in detail and by underlying cause to help decision makers to identify success stories of disease control to emulate, as well as opportunities to improve. Funding: Bill & Melinda Gates Foundation. © 2020 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licens

Psychometric function characteristics of Persian consonant-vowel-consonant words

Background and Aim: Evaluation of word recognition score requires multiple lists that must be similar in terms of difficulty level. There is currently no such word lists for the Persian language. The aim of this study was to construct several lists of Persian monosyllabic words with psychometric homogeneity. Methods: The most common monosyllabic words were collected from a book of Persian word frequency. The selected monosyllabic Consonant-Vowel-Consonant (CVC) words were presented randomly to 30 normal hearing participants with the age range of 18 to 25 years. The presentation level was from 0 to 40 dB in 8 dB increments. The characteristics of psychometric function were determined for all words using the logistic regression. Results: The Persian CVC monosyllabic words have different difficulty levels with threshold varying from 2.8 to 37.2 dB HL and the slope from 2.3 to 16.4 %/dB. Conclusion: The final result of the present study is three full lists of monosyllabic words with CVC syllabic structure that have the same mean threshold and slope of psychometric function. The 25-word half-lists of each full list are similar in terms of psychometric characteristics

Investigation of thermal behavior of energetic and non-energetic binders on luminous efficiency of high performance miniature flares

Miniature flares containing magnesium/sodium nitrate compounded with different binders were studied for increasing luminosity and luminous efficiency in various fuel oxidizer ratio and flare diameters. Unsaturated polyester, Bisphenol-A epoxy resin, calcium resinate, and nitrocellulose were used as binders for construction the flares. Experimental results showed that luminous efficiency was higher for polyester based flares. Due to the difference in decomposition progress of various binders and the exothermic reaction between binder and oxidizer the luminous efficiency of the mixtures were 31000, 28900, 27800 and 25100 cd respectively for polyester, epoxy, calcium resinate, and nitrocellulose. It was found that nitrocellulose as an energetic binder produces the highest light intensity in comparison to other binders, but the burning rate is higher and the burning time is lower than the other binders. Thermal analysis of four binders showed that the heat of reactions was directly related to the amount of light output and luminosity. Keywords: Miniature flare, Illuminating compositions, Luminous efficiency, Binde

The Acceptable Noise Level Benefit From Directionality for Listeners With Severe Hearing Loss

Objectives Directional microphone technology can enhance the speech intelligibility and listening comfort of listeners with hearing impairment. The main aim of this study is to investigate and compare the benefit derived by listeners with severe hearing loss from directional microphone technology with that derived by listeners with moderate hearing loss. Methods The acceptable noise levels (ANLs) of two groups of listeners with moderate or severe hearing impairment (17 subjects in each group) were measured under unaided, omnidirectional-baseline-aided, and directional-aided conditions. Results Although the absolute ANL of the listeners in the severe hearing loss group was significantly higher than that of the listeners in the moderate hearing loss group, their derived benefit was equivalent to that derived by the listeners in the moderate hearing loss group. ANL and hearing loss degree were significantly related. Specifically, the ANL increased with the severity of hearing loss. Conclusion Directional microphone technology can provide the benefits of listening comfort to listeners with severe hearing loss