Equivalent Noise Level Research Articles

Classification of Urban Road Traffic Noise based on Sound Energy and Eventfulness Indicators

Noise energetic indicators, like Lden, show good correlations with long term annoyance, but should be supplemented by other parameters describing the sound fluctuations, which are very common in urban areas and negatively impact noise annoyance. Thus, in this paper, the hourly values of continuous equivalent level LAeqh and the intermittency ratio (IR) were both considered to describe the urban road traffic noise, monitored in 90 sites in the city of Milan and covering different types of road, from motorways to local roads. The noise data have been processed by clustering methods to detect similarities and to figure out a criterion to classify the urban sites taking into account both equivalent noise levels and road traffic noise events. Two clusters were obtained and, considering the cluster membership of each site, the decimal logarithm of the day-time (06:00–22:00) traffic flow was used to associate each new road with the clusters. In particular, roads with average day-time hourly traffic flow ≥1900 vehicles/hour were associated with the cluster with high traffic flow. The described methodology could be fruitfully applied on road traffic noise data in other cities.

Noise Reduction Based on Training Intervention and Using Visual Signs in Neonatal Intensive Care Units (NICUs)

Noise may cause hearing damage and delayed growth and development in newborns in neonatal intensive care units. Hence, it is necessary to reduce noise in these environments. Training and use of visual signs have been investigated as the interventional strategies with the aim of reducing noise level and exposure in neonatal intensive care units. This quasi-experimental study (before and after design) was conducted in the NICU of Birjand University of Medical Sciences Hospital (BUMSH NICU). According to ISO9612 standard, equivalent and maximum noise level in the NICU was measured by a calibrated sound level meter TES model 1358C at various stations during different shifts. Subsequently, the training and visual signs (flags and posters) were utilized as the interventions and SPSS version 18 was used for data analysis. The average equivalent and maximum noise level were calculated between 43.5–69.2 and 55.3–79.2 dBA, respectively, which is above the standards recommended by the American Academy of Pediatrics (AAP). Staff conversation, equipment and alarms were among the main sources of noise pollution. The equivalent noise level showed meaningful reduction before and after the interventions (personnel training and visual signs usage) at night. Noise in our NICU was greater than the recommended sound levels of 45 dBA. However, training and visual signs interventions seemed effective in reducing noise levels, particularly during the night shift. Since conversation was identified as the main noise source, future research is recommended to determine personality traits in healthcare professionals and promote a culture of silence.

Оценка экономической эффективности мероприятий по борьбе с производственным шумом

An assessment of the socio-economic aspects of the negative impact of noise on the human body is given. The procedure for calculating the expected annual economic efficiency of implementing measures to reduce in-plant noise is considered. The dependence of the risk of hearing damage on the equivalent noise level and duration of operation is given. The relationship between measures to reduce in-plant noise and economic losses of the enterprise is established.

The Instensity Measurement And Noise Mapping in Fatty Acid Plant Area At PT. XYZ

PT. XYZ is a factory engaged in processing of palm oil derivatives in producing a fatty acid. The machines used in the processing process at PT. Permata Hijau Palm Oleo KIM II Mabar generate the noise. This research aimed to find out the existing noise level and noise mapping, also the proposal of noise control on the production floor. Then, the data collection method conducted through observation using the equivalent noise level (Leq) method and noise mapping was through surfer 14. The data collection conducted in 16 points on the production floor. Furthermore, the result and noise distribution pattern showed that the high noise level was in several points, those were point 5 (85.77); point 6 (86.82); point 7 (86.33), point 8 (88.18); point 10 (86.96); point 13 (86.85); point 14 (87.67). The allowed threshold value refers to the Decree of the Minister of Manpower and Transmigration No.Per.13/MEN/X/2011 is 85 dB. Thus, the company needs to perform noise control such as barrier usage, regularly and scheduled machine maintenance to prevent and decrease the effect of the noise

Assessment of Fluctuations in Traffic Noise Levels with Simultaneous Traffic Density

Transportation is one of the important pillars of the nation’s economic and overall growth. As transportation is very important, it has its negative impacts on the environment as well as human health. One of its negative impacts is traffic noise pollution. This paper focuses on the study of the relation between traffic density and an increase or decrease in noise levels. The study has been conducted in Surat city, India (tier 2). The noise levels were monitored in a total of 5 stretches and 12 locations of a busy commercial area of Surat city for the day time. Traffic count was done in the form of 2 wheelers, 3 wheelers, 4 wheelers, bus, and trucks. It was found that noise levels in the area are 77dBA, which is higher than the permissible standards set by the Central Pollution Control Board (CPCB) in the Government of India. Also, the study indicates that, if the number of vehicles is increasing, it is not necessary that the equivalent noise level should increase and vice versa, because noise levels are dependent on a lot of other factors like traffic flow, honking of horns, lane indiscipline, unauthorized parking, heterogeneity of vehicles in traffic. Heterogeneous nature of traffic in India and lane indiscipline by vehicle users, traffic often gets congested which results in honking of horns. Ttraffic noise levels are not always directly proportional to traffic count, they may fluctuate very randomly, due to reasons enumerated above.

The impact of port traffic activities on noise level at Jakarta international container terminal I (JICT I) port of Tanjung Priok, North Jakarta

One of the largest and busiest ports in Indonesia that handles more than 30% of Indonesia’s non-oil and gas commodities is located in Tanjung Priok. The purpose of this research is to analyze the noise level and compare it with the noise level standard by Ministry of Environmental regulations No. 48/11/1996 and analyze the noise levels from traffic activities in JICT I. The primary noise level data of Leq (Equivalent Noise Level) on sampling points number 9 at JICT I area was taken using the Sound Level Meter. Secondary data includes the schedule and type of incoming ships, as well as the JICT I Tanjung Priok Port layout. Sampling data was taken during 24 hours activities, which on daytime for 16 hours (06.00-22.00 WIB) and night time for 8 hours (22.00-06.00 WIB). The results showed a high level of noise almost occurred at all points, especially at night and the peak appeared on Saturdays which was with a noise range of 83-85 dB (A). The main noise source is caused by truck and container loading and unloading activities. Therefore, the conclusion is the noise level caused by JICT I Tanjung Priok activites has exceeded the noise level standard by Ministry of Environmental regulation No. 48/11/1996 and by Jakarta Governor’s Regulation No. 551/2001 which was 70 dB(A). The vehicle speed restriction and replacement of crane engine from diesel to electric has been implemented. However, it still have not been able to reduce the impact of the noise. An alternative that can be applied is to use a sound barrier or the construction of Onshore Power Supply (OPS).

Aggregate Impact of Anomalous Noise Events on the WASN-Based Computation of Road Traffic Noise Levels in Urban and Suburban Environments.

Environmental noise can be defined as the accumulation of noise pollution caused by sounds generated by outdoor human activities, Road Traffic Noise (RTN) being the main source in urban and suburban areas. To address the negative effects of environmental noise on public health, the European Environmental Noise Directive requires EU member states to tailor noise maps and define the corresponding action plans every five years for major agglomerations and key infrastructures. Noise maps have been hitherto created from expert-based measurements, after cleaning the recorded acoustic data of undesired acoustic events, or Anomalous Noise Events (ANEs). In recent years, Wireless Acoustic Sensor Networks (WASNs) have become an alternative. However, most of the proposals focus on measuring global noise levels without taking into account the presence of ANEs. The LIFE DYNAMAP project has developed a WASN-based dynamic noise mapping system to analyze the acoustic impact of road infrastructures in real time based solely on RTN levels. After studying the bias caused by individual ANEs on the computation of the A-weighted equivalent noise levels through an expert-based dataset obtained before installing the sensor networks, this work evaluates the aggregate impact of the ANEs on the RTN measurements in a real-operation environment. To that effect, 304 h and 20 min of labeled acoustic data collected through the two WASNs deployed in both pilot areas have been analyzed, computing the individual and aggregate impacts of ANEs for each sensor location and impact range (low, medium and high) for a 5 min integration time. The study shows the regular occurrence of ANEs when monitoring RTN levels in both acoustic environments, which are especially common in the urban area. Moreover, the results reveal that the aggregate contribution of low- and medium-impact ANEs can become as critical as the presence of high-impact individual ANEs, thus highlighting the importance of their automatic removal to obtain reliable WASN-based RTN maps in real-operation environments.

Improving Low-contrast Detectability and Noise Texture Pattern for Computed Tomography Using Iterative Reconstruction Accelerated with Machine Learning Method: A Phantom Study

To evaluate the performance of iterative reconstruction (IR) and filtered back projection (FBP) images in terms of low-contrast detectability at different radiation doses, IR levels, and slice thickness using the mathematical model observer with a focus on low-contrast detectability. The CCT189 MITA CT IQ Low-Contrast Phantom was used and helical scans were performed using a 64-detector CT scanner. Tube voltage was set at 120 kVp and tube current was adjusted from 45 to 600 mA. Images were reconstructed at slice thicknesses of 0.625 and 5.0 mm with FBP and five types of iterative progressive reconstruction with visual modeling (IPV) algorithms. The noise power spectrum (NPS) and normalized NPS were calculated. To evaluate low-contrast detectability, the model observer with the channelized Hotelling observer model was applied using low-contrast modules in the phantom. The NPS and normalized NPS for IPV images had similar curves as that for FBP images. At a slice thickness of 0.625 mm and equivalent radiation dose level, the mean improvement of low-contrast detectability for IPV images was 1.19-2.15-fold greater than FBP images with corresponding noise reduction levels. At equivalent noise levels of 5.0-8.0 HU, low-contrast detectability of the IPVstd2 to IPVstr2 images as almost the same or better than that of the FBP images. However, the detectability of the IPVstr4 image was lower than that of the FBP image (p = 0.02). Low-contrast detectability of the IPV images was improved with a similar normalized NPS as with FBP images. Furthermore, a radiation reduction of >50% was achieved for the IPV images, while maintaining similar low-contrast detectability.

Influence of Honking on the Road Traffic Noise Generated at Urban Rotaries for Heterogeneous Traffic

Abstract This paper presents a study conducted at major rotaries for quantifying the traffic noise levels by considering the vehicle volume and their respective honking as governing parameters for heterogeneous traffic. Traffic volume and traffic noise data was collected using a digital video camera and a class 1 sound level meter, respectively. The traffic noise data was analysed using noise tools for identifying the noise level variation. The data collected was subjected to statistical analysis for light, medium and heavy vehicles, and their contribution towards noise levels is proven to be effective with the forthright fact that, heavy vehicles and their corresponding honking were majorly affecting the equivalent noise level compared to other vehicular proportion. An equivalent noise level [LAeq (dB)] rise of 2 to 6 dB (A) is solely caused by heavy vehicles, which is an important observation to be considered for traffic noise analysis at the rotaries. Based on the obtained results from one of the rotaries, noise prediction model is developed for estimating the LAeq (dB), which is able to predict the noise levels with good precision when validated with the data collected at second rotary intersection for different vehicle volumes.

Wireless Multi-Hop Energy-Efficient System for High-Density Seismic Array

High-density seismic array method has attracted enormous interest in geophysical methods, and it is an advanced seismic observation technology which is of great significance in oil and gas resource detection and underground space exploration. However, designing a portable sensor node that prolongs the lifetime and equips wireless monitoring system to improve construction efficiency has been still a challenge for the high-density seismic array method. In this paper, a portable energy-efficient wireless sensor node and a hybrid communication system that content themselves with complex terrain, large-scale and reliable transmission are proposed to tackle the restrictions of high-density seismic survey. A Wi-Fi communication system based on the star network structure at the core network layer and a ZigBee communication system based on wireless multi-hop structure in the extended network layer form the hybrid communication system. In order to balance the energy of nodes in the extended network and prolong the network lifetime, this paper proposes a multi-hop variable weight routing method (MVWRM). The method selects the cluster-head node and the multi-hop route by changing the weight of the residual energy of the node and the weight of the distance at different periods. Then, a series of simulations and experiments are carried out for verification. The experiments show that the proposed sensor node suggest good performance in equivalent noise level (0.8μV@500Hz, PGA = 1), total harmonic distortion (124dB). Simulation results and performance analysis validate that the effectiveness of the proposed MVWRM can extend about 10% of the node lifetime.

Traffic Noise Assessment among Residential Environment in Batu Pahat, Johore, Malaysia

Noise pollution arises as a severe problem to the community and ground transportation has highly impacted noise environment of the neighbourhood. In the present study, six stations were selected from three different locations in order to assess the traffic noise impact among residential area along Jalan Kluang, Batu Pahat. The objectives of this study focused on two main stages: (1) determination of noise indices; and (2) assessment of traffic noise impact. The noise indices such as equivalent continuous noise level (LAeq), noise level exceeded 10% (L10), 90% (L90) and the maximum noise level (LAFmax) of peak hours measurement time were determined using sound level meter (SLM) at all six stations. Besides, traffic noise index (TNI) and noise pollution level (LNP) were calculated based on the measured noise indices to expose the traffic noise impact. Overall, the result of the present study showed that residential area faces traffic noise disturbance partially whereby 50% of the stations exceeded the DOE standard which was 55dBA. Nevertheless, the residents living nearby Jalan Kluang are commonly facing traffic noise nuisance, but stations located further inside residential areas tend to have more residential background noises apart from traffic influence.

Estimation of Acoustic Safe Distances for Site of a Cassava Processing Mill from Residential Areas of Nigeria

Noise from a source like a cassava processing mill degrades the quality of our environment. The distances at which its sound can be tolerated have to be professionally estimated. This work therefore presents estimation of acoustic safe distances for site of a cassava processing mill from residential areas. Hence, measurements of noise levels with respect to distance, x from the cassava processing mill were considered. The linear regression method was used in analysing the data. Environmental noise models were developed by using the relevant displayed parameters. The results obtained from the models developed in this work, L (modelled) were compared with the results obtained from the physical measurements, L (measured) . The results were also compared with the World Health Organisation tolerant levels. The results reveal that the maximum noise level of the Mcassava processing mill is ((107.97±0.72) dBA. The distances, x c in metres at which its adverse effects covered in the residential areas are , while the distances, x s in metres at which it can be sited from the residential areas are . The results indicate that the equivalent continuous noise level, L eq decreased as x increased. It was shown that there was no significant difference between L (measured) and L (modelled) . Therefore, with the existence of x, the models developed in this work are recommended to be used as more reliable tools for environmental noise impact assessments.

EXPERIMENTAL STUDY OF CARRIAGEWAY OPERATIONAL CONDITION INFLUENCE ON ACOUSTIC ROADSIDE AREA POLLUTION

Environmental noise management is an important part of the policy across the EU policy context, because transportation noise is a significant local environmental problem for most of the urban population. Increasing numbers of vehicles are associated with growing noise levels from road transport in urban areas and rising public health problems. Motor transport is considered to be a main source of noise pollution, so it is important to investigate the level of traffic noise and assess the relationship with traffic flows. The paper describes the main methods for determination of noise characteristics of traffic flows. The dependences for the prediction of the equivalent noise level and the results of field measurements of sound levels are presented. The results of field experiments and the calculated values of sound levels obtained by the analytical method are tested for homogeneity, using the Wilcoxon test. Experimental studies have established that the external sound level depends largely on the speed of vehicles, road conditions, and basic operating characteristics of highways. The analytical method associated with the use of deterministic and probabilistic models makes it possible to predict the traffic noise. But when dealing with the foregoing methods, there arise specific problems, many of which have not been resolved: there is no uniform terminology, nor is there any consensus on the use of noise characteristics of traffic flows in calculations at different stages of construction and reconstruction of highways of a certain traffic flow model under conditions of human settlements. Standardized measurement methods have been established and revised throughout the years by many renowned researchers. These methodologies have been revised in order to minimize problems that may occur and may not be foreseen by a less experienced researcher when adopting the measurement methods. Standardizing the measurement method is also useful for researchers because it becomes possible for researchers from around the world to compare their data. The joint effect of road conditions and the operational status of the roadway on the acoustic pollution of the roadside area is not fully taken into account. Therefore, applying the internationally recognized acoustical measurement standards is a good way to start any noise measurement experiment. The purpose of experimental research is to investigate the joint effect of road conditions and the operational status of the roadway on the acoustic pollution of the roadside area of settlements: identify the main characteristics of noise produced by traffic flows, consider the comparability of results of the field experiment and analytical computations. Slopes of 20…40‰ have little impact on the noise caused by the movement of passenger cars and trucks. In this case, the average acoustic emissions are identical to those used in the prediction of noise mode.

An innovative approach of urban noise monitoring using cycle in Nagpur, India.

Noise is one of the most significant sources of environmental pollution in metro cities. Traffic noise plays an important role to contribute to ambient noise pollution. Noise pollution monitoring was carried out using sound level meter mounted on the cycle with the help of mould fixed on it. Cycle is a noiseless mode of transport and therefore, it was used for noise monitoring over 700 locations in Nagpur City. Noise levels were recorded at each location for 5 min during peak rush hours of traffic in the morning and in the evening at an interval of 1 s leading to around 300 readings each. Noise indices like Leq, L90, L10, Lmax and Lmin were calculated for noise level data analysis. TNI was also determined for analysis of traffic noise on intersections of roads. Equivalent noise levels were transferred into the Geographic Information System (GIS) and spatial analysis tool was used to create spatial and strategic noise maps. Based on the maps, it is revealed that noise levels are exceeded all over the city with respect to ambient noise standards. It was experienced that intersections of roads during peak rush time are very noisy due to honking. The study recommends the noise monitoring through cycle-mounted sound level meter since it covers unapproachable sites, more coverage in the city that helps in identifying hotspot area of concern for noise abatement strategies and planning.

Performance of a Low-Height Acoustic Screen for Urban Roads: Field Measurement and Numerical Study

Field measurements and numerical modelling were used to study the acoustic performance of a low screen in an urban road setting. The results show the usefulness of low screens as well as suggests improvements in screen design. For the measurements, an acoustic screen built up from concrete modules was temporarily installed beside a small park on the reservation between a two-lane road and a track for walking and cycling. A larger traffic system, of which the two-lane road is a part, determines the daytime equivalent noise level within the urban area. The screen height was about 1.4 m as measured from the level of the road surface and the width of the screen top was 0.3 m. Measurements were carried out both at 20 m distance from the road (within the park) and at 5 m distance from the road (at the cycle track). Insertion loss in maximum level, using controlled lightvehicle pass-by at 50 km/h, was measured to 10 dB at 5 m distance and to 6 dB at 20 m distance, at 1.5 m height. Insertion loss in equivalent level was measured within the park to 4 dB at 1.5 m height. A listening experiment confirmed a perceived improvement from installing the screen. The measured results were also compared with predicted results using a boundary element method (BEM) and a noise mapping software, the latter showing good agreement, overestimating the equivalent level insertion loss by 1 dB in the park. The BEM comparison showed reasonable agreement in maximum level insertion loss considering that facade reflections were excluded, with an overestimation of 5 dB at the cycle track, and good agreement in the park, overestimating by up to 1 dB the equivalent and maximum level insertion losses. BEM predictions were used to also investigate other screen designs, showing a positive effect of an acoustically soft screen top, significant for a screen width of 0.2 m and increasing for wider screens.

HYGIENIC ASSESSMENT OF INTERVENTIONS FOR REDUCING EXCESSIVE ACOUSTIC IMPACT ON RESIDENTIAL AREAS

Introduction. The most important external sources of excessive noise levels on the territories of residential development are transportation sources (road, rail, aviation). The aim of the present study is the hygienic assessment of the acoustic situation in the areas in the zone of influence of traffic flows and currently used measures to reduce the excess acoustic impact on residential premises. Material and methods. The studies were carried out on the territories along the roads and Railways, with different intensity of traffic flows in accordance with GOST 23337-2014 Noise. Methods of noise measurement in residential areas and in the premises of residential and public buildings, MUK 4.3.2194-07 “Methods of noise measurement in residential areas and in the premises of residential and public buildings.” Experimental studies of materials used for the construction of acoustic screens were carried out. Here were investigated window units were used to reduce external noise in the house. Sound pressure levels in octave bands (dB) and sound levels (dBA) in the sound-measuring reverberation chamber were measured in accordance with GOST 27296-2012. Results. Exceeding the permissible equivalent noise levels at a distance from 2 to 7.5 m from the roadway of vehicles in the daytime reaches 25-32 dBA. Noise from railway transport at a distance of 25 m from the source in terms of the equivalent sound level for freight transport is of 77 dBA, maximum - 83 dBA; for cargo transport, Sapsan, Lastochka, Allegro identical data were obtained; for passenger trains, the equivalent sound level accounted for 71 dBA, for electric trains - 66-69 dBA. Exceeding the standards for octave frequencies were most often observed at low frequencies from 31.5 to 500 Hz. The air noise insulation index (dB) is higher for the concrete and wood chips material, i.e. the material with higher density. The study of the parameters of the window blocks allowed us to establish all the studied samples to provide a reduction in the equivalent noise level by more than 20 dBA, but differ in the spectral characteristics of noise damping. Conclusion. Traffic flows create excessive noise levels in urban and rural settlements and impair the quality of life of the population. The effectiveness of existing measures aimed to mitigating noise in the source of generation by both road and rail transport has been exhausted. Acoustic screens in high-rise buildings have very limited efficiency. An option to reduce the adverse impact of external noise on public health is the construction of buildings protected from noise. Placement of buildings along the linear objects of road and rail transport should be provided at the stage of planning of quarters, the construction of such buildings should be carried out on special projects. When designing and building, special attention should be paid to the window units used and the quality of their installation. Window blocks should be selected on the basis of frequency characteristics of noise attenuation.

Status quo analysis of noise levels in pig fattening units in Germany

This study was conducted within the MulTiViS-project consortium on multivariate animal welfare assessment. The aim of this investigation was to perform a status quo analysis of the noise level in fattening pig farms (n = 214) and to evaluate the suitability of noise as an animal welfare indicator. In 755 conventional fattening compartments, noise measurements were carried out for one minute at animal height using the Acoustic Analyser XL2, including microphone M2210 (NTI Audio, Schaan, Liechtenstein). In addition, various animal health and environmental factors of 33,668 pigs were recorded in randomly selected pens (n = 1,668) of these compartments. The mean equivalent noise level was 70.2 ± 5.2 dB (min 52.5, max 92.4 dB). Noise levels in compartments housing older pigs were higher (72.0 ± 5.2 dB) than those in compartments housing younger pigs (68.5 ± 4.7 dB, ***P < 0.001). Compartments in which the pigs were fed liquid feed were louder (70.3 ± 4.1 dB) than compartments with dry feed (67.5 ± 6.9 dB, ***P < 0.001). Slightly more noise was caused by partially slatted floors (70.3 ± 6.7 dB) compared to fully slatted floors (70.2 ± 5.0 dB, **P < 0.01), whereas straw bedding tended to reduce the noise level. In addition, the noise level in diffuse fresh air systems was lower (66.7 ± 5.1 dB, **P < 0.01) than in all other ventilation systems. There were no statistical associations identified between animal health factors (e.g. tail biting, ear biting, superficial skin lesions and Bursa auxiliaris) and noise levels. The present study provided useful indications on the status of the noise level in fattening compartments.

Impact of Adjustment of the Static Working Point on the 1/f Noise in a Negative Feedback GMI Magnetic Sensor

The resolution of giant magneto-impedance (GMI)-based magnetic sensor is limited by its equivalent magnetic noise level. It presents a white noise and a low-frequency 1/ f noise behavior. Previous works have showed that the white noise is mainly determined by the electronic conditioning noise, nevertheless, the 1/ f noise’s origin is not totally clear yet. To optimize the 1/ f noise, in this paper, first, we develop an optimized negative feedback GMI sensor. It contains of a low-distortion oscillator, a high-performance amplitude detector, and a GMI sensing element with adjustable static working point. And then, the sensitivity and the 1/ f noise level of the GMI sensor are studied when considering the electronic conditioning parameters and the static working point. The experiment results show that the adjustment of the static working point has a significant effect on the 1/ f noise at low frequencies. The optimal 1/ f noise is obtained by setting the static working point at the position where the GMI element possesses with the maximum intrinsic sensitivity. Finally, we achieve the GMI sensor noise performance of 20 pT/ $\surd $ Hz at white noise region and 100 pT/ $\surd $ Hz at 1 Hz.

Variability of radiated underwater noise measurements for a small research vessel in shallow water

The increased interest in the potential environmental impact of noise from shipping is resulting in the development of measurement methods for determining the radiated noise level and equivalent monopole source level of vessels. It is important to understand the random and systematic uncertainties associated with such techniques. The EU SONIC project provided an opportunity to make repeated measurements on the University of Newcastle research vessel, the Princess Royal, in a shallow water environment (100 m deep) over a number of days. Two multiple hydrophone arrays operated by two of the project partners, CETENA and the University of Southampton, were deployed from the same moored support vessel. This data is reviewed to illustrate the variation associated with such measurements and the impact of using multiple hydrophones and multiple measurement runs on the uncertainty in the radiated noise level and the calculated source level. The results are also compared with a later measurements of the same vessel in a different shallow water environment (20 m deep) using bottom moored hydrophones.

Improving the clinical environment soundscape

This project examines the impact of the clinical acoustic environment on both patients and staff within a large modern inner-city acute hospital (1677 beds). It aims to both summarize and improve the hospital soundscape. Three key parts of experimental work were carried out: noise level measurements were taken in the Queen Elizabeth University Hospital atrium in Glasgow, interviews were undertaken with medical personnel and listening experiments were conducted to assess if adding natural sounds into the environment could reduce the negative effects noise can have on the occupants of the hospital. The atrium area of the hospital was found to be far louder than needed for rest and relaxation, with all recorded equivalent noise levels over 55 dB(A). Relaxing sounds of nature were added to the hospital soundscape to harness the restorative power of nature. The effect of this was tested using the perceived restorativeness soundscape scale; there was mixed evidence that the introduction of natural sounds led to an increase in the environment’s restorative power, with four out of eight attention restoration theory components tested displaying a statistically significant difference. The medical personnel interviewed indicated that the idea of introducing natural sounds is promising and requires further research.This project examines the impact of the clinical acoustic environment on both patients and staff within a large modern inner-city acute hospital (1677 beds). It aims to both summarize and improve the hospital soundscape. Three key parts of experimental work were carried out: noise level measurements were taken in the Queen Elizabeth University Hospital atrium in Glasgow, interviews were undertaken with medical personnel and listening experiments were conducted to assess if adding natural sounds into the environment could reduce the negative effects noise can have on the occupants of the hospital. The atrium area of the hospital was found to be far louder than needed for rest and relaxation, with all recorded equivalent noise levels over 55 dB(A). Relaxing sounds of nature were added to the hospital soundscape to harness the restorative power of nature. The effect of this was tested using the perceived restorativeness soundscape scale; there was mixed evidence that the introduction of natural sounds led to...