Environmental Noise Levels Research Articles

Application of ceramic waste in brick blocks with enhanced acoustic properties

High environmental noise level is currently affecting an increasing amount of people in urban areas, industrial areas, or places with heavy traffic. Therefore, there is a righteous demand for design of building materials and construction elements with improved acoustic properties that ensure a sufficient protection of people affected by noise. Ceramic brick blocks with a system of incorporated voids, which are widely used in the region of Central Europe, can present a prospective solution in that respect. The well-organized manufacturing process, good mechanical and thermal properties and durability of these ceramic products can be considered as supporting arguments for their utilization. The optimization of acoustic properties of brick blocks can be achieved by using waste bulk fillers originating directly in the brick production. This approach generally brings environmental benefits, together with the economic benefits for the producers. In this study, two waste materials of brick-production origin, namely brick rubble and brick microparticles, were characterized in terms of chemical and mineralogical composition at first, along with the characterization of the brick body itself. Then, they were utilized at different dosages as bulk fillers for modified brick blocks. The acoustic properties of the blocks represented by the sound pressure level were determined in the designed small-sized reverberation chambers. It was observed that the utilization of tested waste fillers led to a 10.6–11.7 dB decrease of the average sound pressure level in the frequency range of 50 Hz–5 kHz while the mass increase of the studied brick blocks was 40–47%. The obtained results indicate a successful design of environmental-friendly brick-based materials with enhanced acoustic insulation ability, which was achieved without any significant additional costs.

Robust signal recovery using Bayesian compressed sensing based on Lomax prior

Recently published research shows that Lomax distribution exhibits compressibility in Lorentz curves. In this paper, we address the problem of signal reconstruction in the high noise level and phase error environments in a Bayesian framework of Lomax prior distribution. Furthermore, from the perspective of improving sparsity and compressibility of the signal constraints, a novel reconstruction model deducted from Lomax-prior-based Bayesian compressed sensing (LomaxCS) is proposed. The LomaxCS improves the accuracy of existing Bayesian compressed sensing signal reconstruction methods and enhances the robustness against Gauss noise and phase errors. Compared with the conventional models, the proposed LomaxCS model still reveals the general profile of the signal in the worst conditions. The experimental results demonstrate that the proposed algorithm can achieve substantial improvements in terms of recovering signal quality and robustness; meanwhile, it brings an evident application prospect.

The Accuracy of iPhone Applications to Monitor Environmental Noise Levels.

The Control of Noise at Work Regulations came into force in Great Britain in 2005, requiring all work environments to be monitored for potentially harmful noise exposure levels. This study evaluated the effectiveness of a number of iPhone phone applications (apps) (Apple, Cupertino, CA) to accurately measure noise exposure, which may prove effective when a specialist-calibrated sound level meter is not readily available. Suitable apps were identified using the search terms noise and decibel through the App Store (Apple). Apps that were free to download and had at least one rating were included. Apps were evaluated using a calibrated pure tone sound field and a soundproof testing booth. A 3-frequency audiogram (1000 Hz, 2000 Hz, and 4000 Hz) was used at 25 dB, 40 dB, 55 dB, 70 dB, and 85 dB. Linear regression was carried out to assess accuracy. Nine apps were tested in total, with four out of nine providing a goodness-of-fit coefficient (R2 value) over 0.9. The most effective app was found to be the NIOSH (National Institute for Occupational Safety and Health) Sound Level Meter (EA LAB, Slovenia) with an R2 of 0.97. The least effective app was the Decibel Meter With Recorder (Jianhua Ming, China) with an R2 of 0.62. This study has shown significant variation in the ability of iPhone apps (Apple) to accurately predict environmental dB levels. However, if the correct app is used, an iPhone represents a relatively reliable means of measuring noise exposure levels when a specialist calibrated sound level meter is not readily available. NA Laryngoscope, 131:E59-E62, 2021.

Noise Induced Hearing Loss in Ground Handling Workers at Juanda Airport Surabaya

Background and Objectives The airport ground handling workers are most vulnerable to noise exposure from the sound of aircraft engines that are quite loud and, if exposed continuously, they may experience hearing loss. This study describes the profile of noise induced hearing loss in ground handling workers at Juanda Airport Surabaya.Subjects and Method The descriptive cross sectional approach is employed, and the noise level in the work environment is measured by airport apron, physical ear examination, distortion product otoacoustic emission (DPOAE) and pure tone audiometry, which were conducted for 89 ground handling workers at the airport.Results The age range that experienced hearing loss the most is 50-59 years (19.10%). The male: female ratio of subjects who experienced hearing loss was 50%:53.24%. The highest percentage of subjects with hearing loss was found in the Area II (export-import cargo) with 68%. Workers who experience hearing loss the most have been working for 17-21 years (76%). The ratio of hearing loss between continuous users of ear protectors and occasional or non-users of protectors was 22.47%:30.34%. Of the 89 total research subjects, 47 were found with hearing based on the DPOAE refer results; of these subjects, 30 (33.7%) experienced hearing loss due to noise (NIHL), 9 suffered in the right ear (10.11%), 9 in the left ear (10.11%) and 12 in both ears (13.48%).Conclusion Based on the DPOAE results, 52.81% of the ground handling workers at Juanda airport Surabaya were found with hearing loss; of these workers, 33.7% workers experienced NIHL with 10.11% observed in each ear and 13.48% in both ears.

Evaluation of tube-shaped bus shelters as a noise mitigation solution for passengers

Environmental noise pollution, a worldwide problem, interferes in the physical and mental health of humans. Therefore, noise mitigation measures should be part of urban planning around the world. In Curitiba, Brazil, many bus shelters have a tube-shaped design. The purpose of this work was to ascertain if these tube-shaped bus shelters can mitigate environmental noise that reaches their users. To this end, equivalent sound pressure levels were measured simultaneously inside and outside 40 shelters and the Insertion Loss (IL) was calculated. The difference between the external and internal sound pressure measurements was determined statistically by means of a parametric analysis of variance (one-way ANOVA) and the nonparametric two-sample Kolmogorov-Smirnov test (K-S test). These measurements indicated that tube-shaped shelters reduced environmental noise levels, with IL varying from 2.1 to 8.9 dB(A), and an average IL of 4.9 dB(A). The one-way ANOVA and K-S significance tests, with p-values of 0.0113 and 0.0022, respectively, and with 95% certainty, indicated that IL was generated by the null hypothesis corresponding to the insertion of the tube-shaped bus shelter. Hence, it can be concluded that tube-shaped bus shelters not only enable fast passenger traffic but can also mitigate environmental noise levels.

Robust Audio Content Classification Using Hybrid-Based SMD and Entropy-Based VAD.

A robust approach for the application of audio content classification (ACC) is proposed in this paper, especially in variable noise-level conditions. We know that speech, music, and background noise (also called silence) are usually mixed in the noisy audio signal. Based on the findings, we propose a hierarchical ACC approach consisting of three parts: voice activity detection (VAD), speech/music discrimination (SMD), and post-processing. First, entropy-based VAD is successfully used to segment input signal into noisy audio and noise even if variable-noise level is happening. The determinations of one-dimensional (1D)-subband energy information (1D-SEI) and 2D-textural image information (2D-TII) are then formed as a hybrid feature set. The hybrid-based SMD is achieved because the hybrid feature set is input into the classification of the support vector machine (SVM). Finally, a rule-based post-processing of segments is utilized to smoothly determine the output of the ACC system. The noisy audio is successfully classified into noise, speech, and music. Experimental results show that the hierarchical ACC system using hybrid feature-based SMD and entropy-based VAD is successfully evaluated against three available datasets and is comparable with existing methods even in a variable noise-level environment. In addition, our test results with the VAD scheme and hybrid features also shows that the proposed architecture increases the performance of audio content discrimination.

Territory management based on the assessment of environmental noise in near areas to two medical centers on zone planning units 44 and 47 in Bogotá

Introduction:This article shows the evaluation of environmental noise around the medical centers located in the UPZ Americas and Kennedy Central - Bogotá, and the proposal of some actions related to the planning of the territory as a strategy for mitigation. Problem:The Kennedy town has presented high levels of environmental noise, which is a worrying aspect due to its correlation with the effects on people's health. Objective:This research was conducted for the purpose of compiling updated information on environmental noise in the Kennedy locality and evaluating regulatory compliance and identifing the phenomena to establish actions that lead to its mitigation. Methodology:The measurement process was guided under the guidelines of ISO 1996:1 and the parameters established in Res. 627/2006 of the Ministry of Environment. Results:The ambient noise levels exceed the maximum permissible limits (55 dB) on the different days and hours of measurement. It was also determined that this phenomenon is mainly related to high vehicular flow as well as formal and informal commercial activities around medical centers. Conclusion:There is no regulatory compliance in relation to environmental noise and the territorial plan established in the UPZ. The suggested actions are: use of parks to plant native trees that act as biological barriers, non-use of surrounding streets as secondary traffic roads and reorganization of trade activities. Originality:Updated environmental noise data was obtained around medical centers in Kennedy and problems of inappropriate growth and development were identified. Limitations:Lack of information on environmental noise measurements in other sectors of the area.

Influence of meteorological conditions on noise dispersion in the Port of Thessaloniki

Abstract Although noise dispersion models are widely used for the assessment of noise levels across different domains, the influence of meteorological conditions on environmental noise is usually neglected even though modelling requirements often list meteorological data as a key part for conducting successful modelling exercises. In order to evaluate the magnitude of influence of meteorological conditions on noise dispersion, different meteorological scenarios have been tested. The meteorological parameters that have been addressed include wind speed and direction, air temperature and atmospheric pressure. The simulations have been performed using data obtained from the Port of Thessaloniki, which include standard noise data (locations of noise sources and barriers, noise power levels of individual sources), as well as yearly averages and extremes for the meteorological parameters. Wind speed and direction have been shown to have a major influence on environmental noise levels. The modelled difference in levels due to changes in wind speed and direction reached 7 dB in several receivers indicating an effect that should not be neglected. Air temperature and atmospheric pressure had very little influence on noise levels. In conclusion, when addressing and modelling environmental noise levels, wind speed and direction must be properly accounted for and should not be neglected.

Advanced Signal Sensing Method With Adaptive Threshold Curve Based on Time Frequency Domain Reflectometry Compensating the Signal Attenuation

Adaptive fault detection method, which is compensating the wave attenuation along the propagation, is proposed in this article. Long cable system installed in the factory need to develop precise fault detection method considering propagation dispersion. Using the derived time delay between the incident and reflected wave which is generated from the fault, fault can be localized. The time-frequency cross correlation (TFCC) is a signal scanning process based on the similarity of the energy spectrum for detecting the reflected signal mixed with the noise. The threshold value in TFCC is a reference constant value for judging whether or not a fault is present. Due to the attenuation and dispersion of signal along the propagation, a new threshold value function considering attenuation and dispersion is needed. We propose the adaptive threshold curve for compensating the signal attenuation. We design the equivalent circuit of target cable ( $\text{7}\,\text{m}$ length) and optimal reference signal based on the comparative analysis between the results of computer simulation and actual experiments of $\text{7}\,\text{m}$ length cable. Based on the designed equivalent circuit of target cable( $\text{7}\,\text{m}$ length), a long cable system is modeled by simulation and the performance of the proposed method is proved through the simulation under the various noise level environments.

Daytime perimeter environmental noise in the vicinity of four hospitals in the city of Lima, Peru

Abstract The present study is intended to get to know the levels of perimeter diurnal environmental noise of four hospitals in the city of Lima. The measurement mode used at each hospital was A-weighting, with an integration time of five minutes per recording. It was measured in the FAST mode with calibrations made at the beginning and end of the measurement day. Statistical analysis consisted of the mean comparison T test which was applied at all the hospitals considered in the study. At the four hospitals, at all the hours of measurement and both on working days and non-working days (Sunday), LAeq mean values are higher than 83 dBA. On working days, two periods of maximum noise from 08:00 to 10:00 in the morning and from 17:00 to 19:00 in the afternoon coincide with the start and end of working hours. The perimeter diurnal environmental noise levels determined at the vicinity of four hospitals show higher values in all cases to those established by the Peruvian National Environmental Standards for Noise for special protection areas both for working days and for non-working days. Noise that comes from the dense and disorganized traffic of Lima plays a fundamental role in this behaviour.

Postoperative sleep disorders and their potential impacts on surgical outcomes.

Postoperative sleep disturbance is a common occurrence with significant adverse effects on patients including delayed recovery, impairment of cognitive function, pain sensitivity and cardiovascular events. The development of postoperative sleep disturbance is multifactorial and involves the surgical inflammatory response, the severity of surgical trauma, pain, anxiety, the use of anesthetics and environmental factors such as nocturnal noise and light levels. Many of these factors can be managed perioperatively to minimize the deleterious impact on sleep. Pharmacological and non-pharmacological treatment strategies for postoperative sleep disturbance include dexmedetomidine, zolpidem, melatonin, enhanced recovery after surgery (ERAS) protocol and controlling of environmental noise and light levels. It is likely that a combination of pharmacological and non-pharmacological therapies will have the greatest impact; however, further research is required before their use can be routinely recommended.

Geospatial analysis of environmental noise levels in a residential area in Lagos, Nigeria

AbstractNoise is an inevitable part of daily life and has been identified as a cause of several health deficiencies across the world. It has increasingly become a significant concern on the health and well-being of people. Studies are required to advance knowledge on the sources and impacts of noise in residential neighbourhoods of Lagos State, Nigeria. Therefore, this study assesses the spatial variation of noise levels within a section of the Festac residential area in Lagos in line with noise limits specified by the World Bank Group International Finance Corporation (IFC) Environmental, Health, and Safety (EHS) Guidelines and the Nigerian National Environmental Standards and Regulations Enforcement Agency (NESREA) Noise Standards and Control guidelines for community noise. Data for this research come from a field study comprising measurements of noise levels from 6 observation stations and questionnaire survey with 200 respondents. The criteria for siting the stations was based on factors such as proximity to the roadside, land use and population density, while the questionnaire was administered at random to assess the peoples’ level of awareness on the sources and effects of noise. A digital sound level meter was used to measure noise level variations over a period of 3 weeks for morning, afternoon and evening periods. The measured noise levels were analysed using Analysis of Variance (ANOVA) statistics and the Kriging Geostatistical interpolation technique. Also, logistic regression was used to determine the relationship between the respondents’ perceptions to noise and noise levels. The results indicated that the mean noise levels were within the approximate range of 53.5 – 94.0dBA over the entire period. The highest mean noise levels occurred in the north-western part of the study area where a bus park is present. In general, the noise levels in the area surpass the recommended noise limit of 55dBA, and the logistic regression showed that morning, afternoon and evening mean noise levels were significant predictors of noise variation as perceived by the dwellers. Proper legislation to regulate human activities with respect to noise generation is highly recommended to the local, state and national legislators.

REDUCING ENVIRONMENTAL NOISE IN THE MOTORCYCLE TEST SECTOR

The noise pollution is currently the third biggest environmental problem, affecting many people. When exposed to a high level of noise, the people can show occupational, social, physical and/or psychological problems. The noise is part of people's daily lives and work environments, so research projects and proposals that aim to improve this difficult reality are justified. Personal protection is an immediate measure. However, the control should aim mainly at the emitting source, whether in the noise generation mechanism or in the containment of the propagation. The general objective of this work is the developing of an acoustic booth proposal to reduce environmental noise from the motorcycle test area. The specific objectives are: to map the environmental noise level in the motorcycle testing area; propose an acoustic booth design. In the methodology sought practical results oriented to the problem of controlling environmental noise at the emitting source. An inductive approach is chosen when collecting noise data in the test sector and developing a design as a result of analysing that data. An exploratory, descriptive and explanatory study was developed. Exploratory in data collection, descriptive and explanatory in the development of the acoustic cabin. The investigation strategy uses a case study focused on specifying all qualitative aspects that allow the total reproduction of the results. So, the sound sources that generate noise from the motorcycle test area were verified; area noise levels were measured; the area with the highest noise level was evaluated; the place of installation of the cabin was evaluated; the noise absorbing material was defined; each item used to make the cabin was listed; the costs for making the cabin were defined; the way the panels were assembled was defined; and; The final design of the acoustic booth was designed. The highest noise level found was the motorcycle horn, which when performing the functional test reached an average of 100.91 dB. With the implementation of acoustic booth in the test area, it is proposed to reduce environmental noise in the areas of people circulation.

Fuzzy-based Driver Monitoring System (FDMS): Implementation of two intelligent FDMSs and a testbed for safe driving in VANETs

Vehicular Ad hoc Networks (VANETs) have gained a great attention due to the rapid development of mobile Internet and Internet of Things (IoT) applications. On the other hand, the competition in the automotive industry has turned into an unprecedented race to who will be the first to provide the fully autonomous cars. However, the fully autonomous driving is still a bit far from deployment, and for now, they are providing automation only at a certain level and, at the same time, are offering connected services through their mobility service platforms. With Fog and Edge computing integrated in VANETs, these mobility platforms will be standardized to provide services for every car on the road, which will help VANETs to accomplish one of its main goals, the road safety. In this paper, we propose an intelligent Fuzzy-based Driver Monitoring System (FDMS) for safe driving. We present and compare two fuzzy-based systems: FDMS1 and FDMS2. To make a decision, FDMS1 considers Vehicle’s Environment Temperature (VET), Noise Level (NL) and Heart Rate (HR). While, for FDMS2, we consider Respiratory Rate (RR) as a new parameter to decide Driver’s Situational Awareness (DSA). We evaluate the ability of the driver to safely operate the vehicle by monitoring his condition and subsequently, based on the system output, a smart box informs the driver and provides assistance. We show through simulations and experiments the effect of the considered parameters on the determination of the driver’s situation and demonstrate the actions that can be performed accordingly.

Effect of Factory Process and Location on Residential Area Noise Level

Tranquility is one of the healthy environment factors on the residential areas which elevate the standard of living of the people and their psychological well-being. On the contrary, when there is a high level of noise intrusion at home, it might deprive one of these benefits. This study measured the industrial noise intrusion level in the residential area with respect to distance. A total of 40 residences, with 8 each around 5 food and drug processing factory sites in three local government areas (Idemili North, Onitsha North, and South) of Anambra state, Nigeria were selected as study site locations. Benetech Model GM 1352 digital sound level meter was used for the measurement of environmental outdoor noise levels at a height of 1.5 m and 3 m from any reflecting surfaces. The distance between the factory sites and the residences assessed was calculated using the coordinates of the study site points obtained with A Garmin GPS 72H on the CDXzipdistance2WP function on Microsoft Office Excel. All measurements were carried out during the daytime between 6:00 am – 10:00 pm. Three categories of environmental outdoor samples of noise levels were obtained; off work-hour, and work hour which comprises of generator usage and the national grid connection hours. The computed LAeq noise intensity level obtained at the residences assessed showed that 12(30.0) and 28(70.0) of the residences assessed were quiet and moderately loud during national grid connection hours which was; quiet 32(80) and moderately loud 8(20) during off work-hours. It, however, translated to moderately loud 24(60.0) and very loud 16(40.0) during the engagement of the services of electricity generator. The Pearson correlation analysis showed that there was a strong negative correlation between the distances of the residences assessed from the factory sites and the noise level which were significant at p < 0.01 for values of r = -0.976 during generator use and 0.981 when compared with the national grid. This implies that the closer factory sites are on the residential area the higher the noise intrusion level which is not healthy.

Environmental noise levels and noise annoyance in Novi Sad, 2012-2016

Abstract Objective Increased noise level represents a significant public health problem in urban environments. The aim of this paper is to examine the annoyance of the population by road traffic noise in the City of Novi Sad. Methods The results of 161 24-hour noise measurements in Novi Sad were analyzed. Measurements were done by Public Health Institute of Vojvodina, according to accredited and standardized national methodology during 2012 - 2016. Results Total noise indicator (Lden) / night noise indicator (Lnight) ranged from 61,1 dB / 50,7 dB in residential, up to 66,3 dB / 58,1 dB in recreation / hospital areas, 68,0 dB / 60,3 dB in city traffic areas and 70,2 dB / 62,7 dB in business and residential areas. Taking into account the results and using methodology prescribed by national regulations, the percentage of highly annoyed population (% HA) was found to be in the range 11-25% during the day, and 6-13% during the night. Using ISO 1996-1:2016, prevalence of a population highly annoyed (PHA) was established to be in the range 9,2-33,9% in residential; 18,4-45,7% in recreation / hospital areas 22,9-50,6 in city traffic; 27,7-55,4% in business and residential areas. Conclusions The results confirm that urban noise seriously disturbs people. It was established that about a half of the population was highly annoyed which poses a serious challenge for public health. The results have social, health and economic importance for the population. Activities to reduce the noise level could also stimulate economic, health, social and community programs for sustainable development aiming to preserve and improve human health. Acknowledgment: Supported by the Ministry of Education and Science of the Republic of Serbia - Project “Biosensing Technologies and Global System for Continuous Research and Integrated Management”, No.43002 Key messages Continous noise monitoring is important for understanding the impact of noise on human health. About a half of the population was highly annoyed by noise, which poses a big challenge for public health in urban areas.

Hubungan Tingkat Kebisingan Lalu Lintas Terhadap Kegiatan Belajar Mengajar Di Sekolah (Studi Kasus SDN Buaran 01, Tangerang Selatan)

This study aims to analyze the noise level in the Buaran 01 Elementary School and compare it with the standard noise level, and analyze the relationship of traffic to the disturbance of the school community. Data were collected for 2 weeks at 8 sampling points in the elemtary school area and 1 sampling point on the roadside with a sound level meter. Measurement and data processing methods are in accordance with KepMenLH No.48 of 1996. The results showed the relationship between the number of vehicles and the types of vehicles that passed by is 76.3 dB (A) with the noise level at 01 Buaran Elementary School of 74.6 dB (A). The environment noise level in the elementary school has exceeded the 55 dB (A) from noise level standard for the education area. The correlation between noise level and vehicle equivalent are 4.19% to 54.73% which shows that the noise level can also be influenced by the number of vehicles that passed. As many as 59% of respondents feel disturbed by the noise that occurs. The control efforts that can be done include making barriers in the form of plants, using sound dampening in the room, using door closer to doors and windows, avoiding doors with curved motives, and installing weather stripping in each window so that noises do not enter the window.

Spatial Analysis of Environmental Noise and Auditory Health of Abeokuta Residents, Ogun State, Nigeria

This study assessed environmental noise levels, mapped the spatial pattern at different times of the day and examined the association with morbidity of auditory ailments in Abeokuta metropolis. The entire metropolis was divided into 80 cells (areas) of 1000 m 2 ; out of which 33 were randomly selected for noise levels assessment. Portable noise meter (AR824) was used to measure noise level and Global Positioning System (Garmin GPS-72H) was employed to take the coordinates of the sample sites for mapping. Risk map of the noise levels were produced using Kriging interpolation techniques based on the spatial spread of measured noise values across the study area. Data on cases of hearing impairments were collected from four major hospitals in the city. Data collected from field measurements and medical records were subjected to descriptive (frequency and percentage) and inferential (Mean, ANOVA and correlation) statistics using SPSS (version 20.0). ArcMap 10.1 was employed for spatial analysis and mapping. Results showed mean noise levels range at morning (42.4±4.14 – 88.2±15.1 dBA), afternoon (45.0±6.72– 86.4±12.5 dBA) and evening (51.0±6.55–84.4±5.19 dBA) across the study area. The interpolated maps identified Kuto, Okelowo, Isale-Igbein and Sapon as high noise risk areas. The monitored noise levels varied significantly among the sampled areas at morning, afternoon and evening (p <0.05). Significant correlation was found between diagnosed cases of auditory ailments and noise levels measured in the morning (r=0.39 at p<0.05). Common auditory ailments found across the metropolis included impaired hearing (25.8%), tinnitus (16.4%) and otitis (15.0%) respectively. Keywords : Abeokuta metropolis, Noise, spatial pattern, auditory impairment

Comparison of land use regression and random forests models on estimating noise levels in five Canadian cities

Chronic exposure to environment noise is associated with sleep disturbance and cardiovascular diseases. Assessment of population exposed to environmental noise is limited by a lack of routine noise sampling and is critical for controlling exposure and mitigating adverse health effects. Land use regression (LUR) model is newly applied in estimating environmental exposures to noise. Machine-learning approaches offer opportunities to improve the noise estimations from LUR model. In this study, we employed random forests (RF) model to estimate environmental noise levels in five Canadian cities and compared noise estimations between RF and LUR models. A total of 729 measurements and 33 built environment-related variables were used to estimate spatial variation in environmental noise at the global (multi-city) and local (individual city) scales. Leave one out cross-validation suggested that noise estimates derived from the RF global model explained a greater proportion of variation (R2: RF = 0.58, LUR = 0.47) with lower root mean squared errors (RF = 4.44 dB(A), LUR = 4.99 dB(A)). The cross-validation also indicated the RF models had better general performance than the LUR models at the city scale. By applying the global models to estimate noise levels at the postal code level, we found noise levels were higher in Montreal and Longueuil than in other major Canadian cities.

Auditory EEG Biomarkers in Fragile X Syndrome: Clinical Relevance.

Sensory hypersensitivities are common and distressing features of Fragile X Syndrome (FXS). While there are many drug interventions that reduce behavioral deficits in Fmr1 mice and efforts to translate these preclinical breakthroughs into clinical trials for FXS, evidence-based clinical interventions are almost non-existent potentially due to lack of valid neural biomarkers. Local circuit function in sensory networks is dependent on the dynamic balance of activity in inhibitory/excitatory synapses. Studies are needed to examine the association of electrophysiological alterations in neural systems with sensory and other clinical features of FXS to establish their clinical relevance. Adolescents and adults with FXS (n = 38, Mean age = 25.5, std = 10.1; 13 females) and age matched typically developing controls (n = 40, Mean age = 27.7, std = 12.1; 17 females) completed auditory chirp and auditory habituation tasks while undergoing dense array electroencephalography (EEG). Amplitude, latency, and percent change (habituation) in N1 and P2 event-related potential (ERP) components were characterized for the habituation task; time-frequency calculations using Morlet wavelets characterized phase-locking and single trial power for the habituation and chirp tasks. FXS patients showed increased amplitude but some evidence for reduced habituation of the N1 ERP, and reduced phase-locking in the low and high gamma frequency range and increased low gamma power to the chirp stimulus. FXS showed increased theta power in both tasks. While the habituation finding was weaker than previously found, the remaining findings replicate our previous work in a new sample of patients with FXS. Females showed less deficit in the chirp task but not the habituation task. Abnormal increases in gamma power were related to more severe behavioral and psychiatric features as well as reductions in neurocognitive abilities. Replicating electrophysiological deficits in a new group of patients using different EEG equipment at a new data collection site with differing levels of environmental noise that were robust to data processing techniques utilizing multiple researchers, indicates a potential for scalability to multi-site clinical trials. Given the robust replicability, relevance to clinical measures, and preclinical evidence for sensitivity of these EEG measures to pharmacological intervention, the observed abnormalities may provide novel translational markers of target engagement and potentially outcome measures in large-scale studies evaluating new treatments targeting neural hyperexcitability in FXS.