Equivalent Continuous Sound Pressure Level Research Articles

Effects of acoustic environment on sleep and mental health in residential regions near railways

Noise is an important environmental risk factor for physical and mental health. Furthermore, long-term noise exposure is burdensome for the mind and body and has become a serious problem. Rail transportation is one of the main methods used to transport goods in China; however, the noise and vibrations generated by freight trains have serious impacts on residents in nearby regions. To further investigate the relationship between railway noise and road noise exposure and changes in sleep duration and mental health scores, a field study in Harbin, China, was conducted and a health risk prediction model was constructed. The results showed that for every 1 dB increase in the Equivalent continuous A-weighted sound pressure level (LAeq), the percentage of deep sleep among residents living near the railway decreased by 0.2 %. Although residents near the railway reported similar sleep evaluations compared to those living farther away, they exhibited poorer mental health. Cox risk modeling indicates that the risk of mental health problems is approximately three times higher for those living near the railway. These findings potentially provide benefits in developing strategies to reduce the risk of mental illness for people residing near railways.

Sound pressure level in the speech signal due to the use of a mask or face shield

Introduction: the use of masks and face shields became widespread during the COVID-19 pandemic, but their impact on vocal health, especially in those who use their voice as a work tool, is not yet fully studied. This study investigates the effect of different types of masks and face shields on the sound pressure level of the voice, with special attention to the risk of developing vocal pathologies.Methods: voice recordings were made of 18 participants (11 women and 7 men) in an audiometric booth, measuring the equivalent continuous sound pressure level (Leq) with a sound level meter. The results obtained with different types of masks (surgical, KN95, with transparent window) and a face shield were compared.Results: no significant differences were found in Leq between the groups with and without protective elements. However, it was observed that women tend to increase the intensity of their voice when wearing masks or face shields, which could lead to greater vocal effort and a potential risk of developing long-term vocal pathologies.Conclusions: Although the use of masks and face shields is necessary in certain contexts, it is important to consider the possible consequences for vocal health, especially in women. The use of non-verbal language is recommended to complement communication and avoid combining KN95 masks with face shields when not strictly necessary.

Silent Neonatal Incubators, Prototype Nica+

Objectives: The purpose of this study was to evaluate and compare the noise levels in current incubator models and a prototype designed to improve acoustic comfort in neonatal incubators. Methods: Tests were carried out on three different models of incubators and a prototype called Neonatal Incubator Acoustic Comfort Class (NICA). The tests measured both internal and external sound pressure levels under laboratory conditions. The noise index has been taken as the A-weighted equivalent continuous sound pressure level (LAeq,T) for a time interval of 1 min. Results: The results obtained show variations between the different models of incubators, although, overall, they are high values (around 56/60 dBA). The results prove that premature newborns under normal conditions of using these incubators are exposed to noise levels above international recommendations. The new incubator design minimizes noise generation and generates noise levels lower than international recommendations. Conclusions: The results obtained from the prototype (NICA+) show the effectiveness of the proposed design in improving acoustic comfort in neonatal incubators. The data show that the noise levels generated by the prototype under normal operating conditions are significantly lower than international recommendations.

Power saw noise levels during steel stud cutting tasks on commercial construction sites: a tool characterization from a worker exposure standpoint.

Construction framers who cut and install steel studs as part of their daily tasks are exposed to hazardous noise levels during their work shift in large part due to the power saws they use to cut steel studs. This investigation characterized the sound pressure levels of power saws used to cut steel studs on active construction sites. Further, the length of time it took to cut various studs on a construction site was investigated to understand worker exposure times to saw noise. In general, power saws used on the study sites to cut steel studs had a mean A-weighted equivalent continuous sound pressure level (LAeq) of 107.2 dB and a C-weighted peak sound pressure level (LCpeak) of 120.1 dB. Three of the saws-the chopsaw, the cut-off saw, and the grinder-had similar noise levels, whereas the cordless circular saw had higher noise levels. It took an average of 13.2s to cut each stud, and workers in the study used power saws to cut steel studs for an average of 371.5s per day. This average exposure time at the average recorded sound pressure levels (SPLs) suggests these saws can increase the risk of occupational noise-induced hearing loss, according to National Institute for Occupational Safety and Health (NIOSH) recommendations.

Forecasting an urban sound model using space syntax theory in three different urban patterns in Egypt

The objective of this study is to investigate an acoustic environment based on spatial configurations. To achieve this objective, two types of data were utilized. First, the urban acoustic data was collected from 96 measurements based on equivalent continuous A-weighted sound pressure levels across three different urban areas in Cairo, Egypt, during weekends and at night. The data was plotted on a contour map in an effort to investigate their distribution in the urban area. Secondly, the data was collected using DepthMapX software, and in this way, spatial analysis was produced with diverse spatial attributes. Moreover, on-site observations of pedestrian and traffic rates were made, and land use distribution was observed.Statistical analysis was also conducted using the Statistical Package for Social Sciences (SPSS). Our statistical analysis showed that the value of sound pressure level (LAeq) is greatly influenced by spatial attributes in highly accessible spatial configurations, with Normalized Angular Integration (NAIN) being the most accurate predictor of sound pressure level. Our findings also verified the existence of a high correlation between commercial and mixed land uses and (LAeq).Additionally, this study revealed that the urban sound model can predict sound pressure level (LAeq) in an urban setting. This dataset functions as a valuable resource for future research, urban designers, and policymakers who are addressing sustainable issues pertaining to soundscape, noise pollution, and urban planning.

Study on impact of robotic-assisted orthopaedic industrial noise (SIREN).

The aim of this study was to evaluate noise exposure to the operating room staff consisting of the surgeon, assistant, anaesthetist and Mako Product Specialist (MPS) during Mako robotic-arm assisted total knee arthroplasty (TKA) and total hip arthroplasty (THA). We aimed to determine whether employees were exposed to noise at or above a lower exposure action value (LEAV) set out by the Noise at Work Regulations 2005, Health and Safety Executive (HSE), UK. We prospectively recorded intra-operative noise levels in Mako robotic-arm assisted TKA and THA over a period of two months using the MicW i436 connected to an iOS device (Apple), using the Sound Level Meter App (iOS) by the National Institute for Occupation Safety and Health (NIOSH). Data obtained was then used to calculate "worst case" daily exposure value to assess if sound levels were compliant with UK guidelines. Comparison between operating room staff groups was performed with ANOVA testing. A total of 19 TKA and 11 THA operations were recorded. During TKA, for the primary surgeon and the assistant, the equivalent continuous sound pressure level (LAeq) was over 80 dB, exceeding the LEAV set out by the Noise at Work Regulations by HSE. During THA, the average LAeq and peak sound pressure levels did not exceed the LEAV. The calculated daily exposure for the primary surgeon in TKA was 82 dB. A Tukey post hoc test revealed that LAeq was statistically significantly lower in the anaesthetist and MPS (p < .001) compared to the primary surgeon and assistant in both TKA and THA. Operating room staff, particularly the primary surgeon and assistant are exposed to significant levels of noise during Mako robotic-arm assisted TKA and THA. Formal assessments should be performed to further assess the risk of noise induced hearing loss in robotic-arm assisted arthroplasty.

Coupling Different Road Traffic Noise Models with a Multilinear Regressive Model: A Measurements-Independent Technique for Urban Road Traffic Noise Prediction.

Road traffic noise is a severe environmental hazard, to which a growing number of dwellers are exposed in urban areas. The possibility to accurately assess traffic noise levels in a given area is thus, nowadays, quite important and, on many occasions, compelled by law. Such a procedure can be performed by measurements or by applying predictive Road Traffic Noise Models (RTNMs). Although the first approach is generally preferred, on-field measurement cannot always be easily conducted. RTNMs, on the contrary, use input information (amount of passing vehicles, category, speed, among others), usually collected by sensors, to provide an estimation of noise levels in a specific area. Several RTNMs have been implemented by different national institutions, adapting them to the local traffic conditions. However, the employment of RTNMs proves challenging due to both the lack of input data and the inherent complexity of the models (often composed of a Noise Emission Model-NEM and a sound propagation model). Therefore, this work aims to propose a methodology that allows an easy application of RTNMs, despite the availability of measured data for calibration. Four different NEMs were coupled with a sound propagation model, allowing the computation of equivalent continuous sound pressure levels on a dataset (composed of traffic flows, speeds, and source-receiver distance) randomly generated. Then, a Multilinear Regressive technique was applied to obtain manageable formulas for the models' application. The goodness of the procedure was evaluated on a set of long-term traffic and noise data collected in a French site through several sensors, such as sound level meters, car counters, and speed detectors. Results show that the estimations provided by formulas coming from the Multilinear Regressions are quite close to field measurements (MAE between 1.60 and 2.64 dB(A)), confirming that the resulting models could be employed to forecast noise levels by integrating them into a network of traffic sensors.

Acute effects of military aircraft noise on sedative and analgesic drug administrations in psychiatric patients: A case-time series analysis

BackgroundExisting evidence suggests that psychiatric patients are highly noise sensitive, and that noise exposure increases the risk for adverse mental health outcomes, such as psychiatric hospitalizations and even suicide. To investigate acute effects of noise in this vulnerable population, we assessed short-term associations between fighter jet noise and on-demand sedative and analgesic drug administrations in a psychiatric clinic located close to a military airfield in Switzerland. MethodsWe applied a case time series analysis with an hourly time resolution using distributed-lag models. Analysis was adjusted for long-term and seasonal trends, day of week, time of day, time-varying weather conditions and the week of stay. Noise exposure (hourly A-weighted equivalent continuous sound pressure levels (LAeq)) was modelled using detailed flight plans and noise footprints for different fighter jet and route combinations. Outcome data were available from the clinic’s records. OutcomesDuring the study period (06/2016–12/2021), 23,486 flights occurred. 5,968 clinical stays with a median length of 41 days (IQR: 28d, 50d) were recorded. The odds ratio (OR) for medication administration over the lag period of 3 hours after exposure was 1.016 (95 %CI: 1.006, 1.026) per 10 dB LAeq for sedatives and 1.032 (95 %CI: 1.016, 1.048) per 10 dB for analgesics. Effects were larger in multimorbid patients. InterpretationCase time series analysis is a novel method to investigate transient associations in observational data while minimizing risk of bias. Using an objectively recorded outcome measure, our results demonstrate that psychiatric patients are a vulnerable population, in which noise exposure can lead to symptom exacerbations and adverse events.

Real-time Noise Risk Assessment as Preventive Action to Occupational Disease in A Pharmaceutical Industry

Noise is a form of dangerous exposure that occurs around humans because of sound sources from industrial machines, work equipment, alarms, transportation equipment, etc. Continuous exposure to noise with noise levels higher than 85 dBA can lead to psychological and psychological health problems. The aim of this research is to identify the intensity of noise in the pharmaceutical industry and to map the noise to humans. Noise evaluation began by conducting a survey of conditions on the production floor by arranging a production floor layout accompanied by the location of machines and other work facilities. The next step was to determine the size and number of networks that would help in identifying interference measurement points. It took around 100 points to identify interference and then measurements were carried out using a noise meter with 6 repetitions per point. The equivalent continuous sound pressure level (Leq) was calculated first before being used as input to the Surfer software to obtain interference on the production floor. The research results showed that there were 100 points spread across 12 workstations in this drug manufacturing industry. The results showed that there were 19 points that received interference ≥ 85 dBA. The areas with the biggest disturbances were the EPM machine area, spooling machine, and slitting room.

Psychological and physiological evaluations of time-varying noises produced by air conditioners

Air conditioners are widely used in buildings to maintain thermal comfort for long time. Air conditioners produce sounds during operation, and air conditioners are regarded as one of the main noise sources in buildings. Most sounds produced by the air conditioner do not fluctuate over time and sound quality of the steady sounds produced by the air conditioner have been evaluated. However, air conditioners sometimes produce time-varying noises. Customers criticizes such noises are annoying when they sleep and they spend time quietly in the living room. The aim of this study was to determine the factors that significantly influence the psycho-physiological response to the time-varying noises produced by air conditioners. We assessed the A-weighted equivalent continuous sound pressure level (LAeq) and factors extracted from the autocorrelation function (ACF). Subjective loudness, sharpness, annoyance, and electroencephalography (EEG) were evaluated. Relationships between psychological and physiological responses and physical parameters, LAeq, the ACF factors, and their standard deviation, were determined. The LAeq and peak of the first maximum peak of the ACF were identified as significant factors for the time-varying noises.

Environmental controls of air-conditioned noise with the aid of the Psychoacoustics Perception Scale (PPS)

It is known that an air-conditioning system is an essential component of modern buildings for maintaining good indoor environmental quality. However, the adverse effect due to air-conditioned noise can offset its benefits. Although several noise indices such as Noise Criteria (NC), Noise Rating (NR), Room Criteria (RC), and A-weighted equivalent continuous sound pressure level (LAeq) have been developed to assess the acceptability of indoor noise environments, the noise feature of the environments and its psychological impacts on the occupants are not comprehensively evaluated. Psychoacoustics Perception Scale (PPS) is a psychometric tool to assess the psychological impacts about general judgment (Evaluation, E), sensitivity to the magnitude (Potency, P), and sensation of the temporal and spectral compositions (Activity, A) of noise on occupants. This study aimed to evaluate the air-conditioning building environments by using the traditional noise indices, psychoacoustic metrics, and the PPS. The significant correlations were found between the objective and subjective data. The results of the study provided the useful knowledge on future designs of the environmental controls of air-conditioned noise.

A Statistical Analysis of Robust Cicada Noise Level

When cicadas are chirping loudly during the traffic noise measurements in summer, it is difficult to obtain the correct traffic noise level. In the previous study, there were few reports on cicada noise levels, and the reports showed that the levels were uncertain, for example, as the cicada noise reached around 56 dB in the forest. Our aim was to investigate the details of the noise levels of robust cicadas. We measured the sound pressure level of the cicada noise in a free field. In addition, they were measured some features; the noise waveform, body length, total length and weight. The waveform was estimated to the equivalent continuous sound pressure level (LAeq) at 1 m per a cicada, where the level was extracted while the cicada sounds violently. The measurement data included of the levels of 77 cicada noises for statistical analysis. The type of LAeq distribution was normally distributed, and the mean value was 73.1 dB (standard deviation = 3.5 dB). The cicada measurements were normally distributed for body length, total length, and weight. However, there were no correlations between the LAeq and body length in the scatter plot results.

Variations in sound environment in an urban apartment building: A case study during and after the COVID-19 lockdown

Quiet communities, which are encouraged to maintain a harmonious and tranquil urban living environment, have attracted increasing attention in designing method in recent years. The relevant residential standards specify quiet thresholds with regard to noise pollution issues. However, the variation in height across floors of high-rise buildings and variation with time in sound environments have not been examined in detail. The city of Shanghai experienced a city-wide lockdown to control the spread of COVID-19, showing evidence of quietness and a significant reduction in anthropogenic noise. Here, we conducted noise monitoring in a 14-storey apartment building that was surrounded and shielded by other buildings in a typical urban community during and after the lockdown. The mean value of all 14 floors of equivalent continuous A-weighted sound pressure level (LAeq,T) after lockdown was systematically greater than that during lockdown, with differences of 3.6 and 3.1 dB during the daytime and night-time periods, respectively. We suggest that in practice, it is useful to consider the specific floor or time of day.

Risk of noise-induced hearing loss in the spine surgeon

Occupation-related noise-induced hearing loss (NIHL) has both negative economic and quality of life implications. The risk spine surgeons undertake in regards to NIHL during operative intervention is unknown. Governing bodies, including the National Institute for Occupational Safety and Health, have recommended exposure limits not to exceed 85 decibels (dB) over 8 hours. The purpose of this study is to characterize noise exposure to spine surgeons in the operating room (OR). Prospective collection of intraoperative recordings of spinal surgeries (cervical and thoracic/lumbar) was undertaken. Data gathered included procedure, operative duration, presence of background music, and noise information. Noise information included maximum decibel level (MDL), Peak level (LCPeak), Equivalent continuous sound pressure level, time weighted average (TWA), dose, and projected dose. Noise measurements were compared with baseline controls with and without music (empty ORs). Two hundred seven noise recordings were analyzed. One hundred eighteen of those being spinal surgeries, 49 baseline recordings without music, and 40 with music. Maximum decibel level reached a maximum value of 111.5 dBA, with an average amongst surgical recordings of 103 dBA. Maximum decibel level exceeded 85 dBA in 100% of cases and was greater than 100 dBA in 78%. The maximum LCPeak recorded was 132.9 dBC with an average of 120 dBC. Furthermore, the average dose was 7.8% with an average projected dose of 26.5%. The highest dose occurred during a laminectomy at 72.9% of daily allowable noise. Maximum projected dose yielded 156% during a 3-level anterior cervical discectomy and fusion. Spine surgeons are routinely exposed to damaging noise levels (>85 dBA) during operative intervention. With spine surgeons often performing multiple surgeries a day, the cumulative risk of noise exposure cannot be ignored. The synergistic effects of continuous and impact noise places spine surgeons at risk for the development of occupation-related NIHL.

Assessment of noise pollution of fireworks during Christmas and New Year in the city of Buenos Aires: comparison with a different management strategy applied to the city of Santiago de Chile

Fireworks are widely celebrated worldwide but have raised environmental concerns due to pollutant emissions. This has prompted evolving legislation in many countries, necessitating scientific evidence for policy development. Existing literature mainly focuses on characterizing individual fireworks and quantifying noise variations between festive and non-festive periods. However, no such studies have been conducted in Argentina. This study aims to characterize noise levels generated by fireworks during the 2020 Christmas and New Year celebrations in Buenos Aires. Nine measurement systems were used, obtaining acoustic descriptors reflecting noise levels during these events. Results were compared with typical ambient noise levels in the city and those during the New Year's fireworks display in Santiago de Chile, where public access to individual fireworks is restricted. Findings indicate significant noise level increases during the Christmas and New Year celebrations, supported by the L01 percentile acoustic parameter, more effective in characterizing impulsive events than Equivalent continuous sound pressure level LeqA. Comparing results with Santiago de Chile, noise values in Argentina remained similar within a 1.1 km proximity to the fireworks show, whereas beyond that distance, Chilean residents experienced lower noise levels.

Sound Environment during Dental Treatment in Relation to COVID-19 Pandemic

This study delves into the acoustic environment within dental clinics, particularly focusing on the impact of extraoral suction devices employed for infection control amid the COVID-19 pandemic. The research encompasses a comprehensive investigation, including a questionnaire survey of dental professionals, sound level measurements at suction device openings, acoustic imaging, and a detailed analysis of sound levels and their spectral characteristics during dental procedures. Additionally, ambient sound levels within clinical settings were monitored over two consecutive days. The findings reveal notable observations. Dental professionals expressed concerns regarding increased sound levels and associated distress caused by extraoral suction device operation. Objective measurements identified varying A-weighted sound pressure levels ranging from 86.0 dB to 96.7 dB at suction device openings, highlighting elevated sound pressure levels and a wide frequency range, especially in the vicinity of both the dentist and the patient’s facial area during dental aerosol procedures. On the other hand, for the entire clinical room, the equivalent continuous A-weighted sound pressure level during the consultation hours was not considered problematic. In light of these findings, it becomes evident that there is a pressing necessity to refine the acoustic characteristics of extraoral suction devices to foster a more accommodating acoustic environment for both patients and dental healthcare professionals within dental clinics.

Effects of Audio-Visual Environmental Factors on Emotion Perception of Campus Walking Spaces in Northeastern China

In the context of urban sustainable development and the creation of pedestrian-friendly campus environments, optimizing campus walking spaces has emerged as a central focus in urban planning research. Presently, research in pedestrian environments predominantly adopts a macroscopic perspective, offering limited insights into pedestrians’ subjective experiences and emotional perceptions at a micro level. Therefore, this study conducted on-site experiments in 21 walking spaces across three campuses, utilizing image semantic analysis, multifunctional sound level meter, wearable electrocardiography devices, and the Profile of Mood States (POMS) to collect data separately on audio-visual environmental factors and pedestrians’ emotional states. This study’s findings revealed significant correlations (p &lt; 0.01) among factors such as the Green Visual Index, Spatial Enclosure Index, Sky Visibility Index, Spatial feasibility Index, and Equivalent Continuous A-weighted Sound Pressure Level with physiological and psychological alterations in pedestrians’ emotions. Additionally, the various proportions of audio-visual environmental factors also exerted significant influences on emotions (p &lt; 0.05). The relevant conclusions can provide a reference for optimizing the audio-visual environment of walking space and promoting the sustainable development of the campus. In future research, the effects of audio-visual environments on both emotional and physiological indicators, as well as subjective evaluations, can be explored further.

Clustering analysis of noise sources in healthcare facilities

Hospital environmental noise can impact the comfort of both workers and patients, causing sleep disturbances and hindering the recovery process. Environmental noise in hospitals is typically due to the mixture of various sound sources, including staff, outdoor noises, and mechanical equipment. Patients and staff experience different effects from noise contributions: the former's recovery process is influenced, while the latter's communication efficiency is compromised. Conventional measurements are based on equivalent continuous sound pressure levels. However, the latter does not provide any kind of details about the hospital's sound context. Unsupervised acoustic measurements have been already used in many fields, but still in a few healthcare scenarios. For this reason, a clustering technique has been used to deepen the conventional noise analysis. The Gaussian Mixture Model (GMM) is used to identify and quantify the contributions of the main types of sound sources. This analysis has been conducted within two four-bed bays: one in active conditions and the other unoccupied. The GMM analysis involves the noisiest period of the day, the morning round. The results demonstrate the GMM's ability to overcome conventional practices by providing significant insight into environmental noise, even in active conditions. In the active room, noise sources were tagged and measured. The spectral matching, based on the empty room's outcomes and standard references, represents the benchmark to assess the reliability of the method.

Daily sound exposure of hearing aids users during COVID-19 pandemic in Europe.

This study aimed to investigate the daily sound exposure of hearing aid (HA) users during the COVID-19 pandemic, with a specific focus on the impact of different governance intervention levels. Modern HA technology was employed to measure and compare the sound exposure of HA users in three distinct periods: pre-pandemic, and two 14-day periods during the pandemic, corresponding to varying levels of governance interventions. The study sample comprised a total of 386 HA users in Europe during the pandemic, with daily sound exposure data collected as part of the main dataset. The results revealed that, during the pandemic, the equivalent continuous sound pressure level (SPL) experienced by HA users decreased, while the signal-to-noise ratio (SNR) increased compared to the pre-pandemic period. Notably, this impact was found to be more pronounced (p < 0.05) when individuals were subjected to stronger governance intervention levels, characterized by lower SPL and higher SNR. This study highlights the changes in daily sound exposure experienced by HA users during the COVID-19 pandemic, particularly influenced by the extent of governance interventions that restricted social activities. These findings emphasize the importance of considering the effects of pandemic-related governance measures on the sound environments of HA users and have implications for audiological interventions and support strategies during similar crises.

Comparison of cabin noise of turboprop and turbofan aircrafts

Turboprop aircrafts are typically used for transporting cargos and for low-capacity short-haul air transport between regional cities. The new designs of turboprop aircrafts tend to focus on noise and comfort level of the aircrafts. Although turboprop aircrafts are known to have relatively higher cabin noise, there are limited reported studies in the open literature examining the actual cabin noise level in commercial flights. In this study, the cabin noise of the ATR 72-500 turboprop aircraft was examined and compared with that of the Bombardier CRJ 900 turbofan aircraft during actual commercial flights. Both are passenger planes which are designed to carry fewer than 100 passengers and are deemed to be a more compatible comparison. Both are single isle aircraft with two seats on each side of the isle. The Bombardier CRJ 900 is found to have a lower cabin noise in terms of both dBA and dBC for both taxing and cruising. As the average equivalent continuous sound pressure level (Leq) for cabin noise is found to be well below 85 dBA, there is no risk of exceeding the daily exposure to noise of 85 dBA for eight hours under the National Institute for Occupational Safety & Health (NIOSH) regulation. However, as many reported studies have shown that prolonged exposure to low frequency noise may lead to disorders, discomfort, sensitivity to and irritability from noise, annoyance, hearing loss, and cardiovascular diseases, there may be a need to carry out a more detailed study of the effect of low frequency noise on passengers.