Search

Introduction: Forests managed for timber production can also be managed for biodiversity conservation by retaining structures typical of old-growth forests, which provide heterogenous structures for forest-dwelling species, including birds. Ecoacoustic monitoring of forest birds is now a well-studied field, however the extent to which acoustic indices can reflect bird assemblage responses to stands of lower or higher structural heterogeneity is disputed. Method: In this study, we acoustically surveyed 75 plots over two years in mature, previously managed forests and computed acoustic indices from the recordings. We first identified an acoustic index that significantly correlated with bird richness over more than one spring season. Next, we tested the response of bird richness to individual forest structural elements using linear regressions. We then repeated this analysis but combined the individual structural elements into one structural composition variable using an NMDS and gam smooth overlay, to compare the effect of individual forest structures versus overall forest heterogeneity on bird richness. We then repeated this analysis using our selected acoustic index, the Normalized Difference Soundscape Index (NDSI), to see if it followed the same patterns as bird richness in response to individual and collective forest structural elements. Results: Our results showed that plots with high bird richness were also associated with high NDSI values, and high values of both variables occurred in plots with high structural heterogeneity (tree species richness, tree size variability, and snag height variability) and low amounts of standing and lying deadwood. Discussion: Our findings suggest that once an acoustic index can be identified as a robust correlate of bird richness, it can serve as a proxy for the response of birds to differences in forest structural heterogeneity within a managed forest context. It is therefore possible for forest managers interested in conserving or increasing bird richness in their production forests to identify a robust acoustic index to track the response of bird richness to management decisions over time. [ABSTRACT FROM AUTHOR]

Eco-acoustic indices allow us to rapidly evaluate habitats and ecosystems and derive information about anthropophonic impacts. However, it is proven that indices' values and trends are not comparable between studies. These incongruences may be caused by the availability on the market of recorders with different characteristics and costs. Thus, there is a need to reduce these biases and incongruences to ensure an accurate analysis and comparison between soundscape ecology studies and habitat assessments. In this study, we propose and validate an audio recording equalization protocol to reduce eco-acoustic indices' biases, by testing three soundscape recorder models: Song Meter Micro, Soundscape Explorer Terrestrial and Audiomoth. The equalization process aligns the signal amplitude and frequency response of the soundscape recorders to those of a type 1 level meter. The adjustment was made in MATLAB R2023a using a filter curve generated comparing a reference signal (white noise); the measurements were performed in an anechoic chamber using 11 audio sensors and a type 1 sound level meter (able to produce a.WAV file). The statistical validation of the procedure was performed on recordings obtained in an urban and Regional Park (Italy) assessing a significant reduction in indices' biases on the Song Meter Micro and Audiomoth. [ABSTRACT FROM AUTHOR]

In this paper, we present the results of the noise monitoring in the urban area of Milan, Italy, associated with COVID-19 outbreak. In order to limit the diffusion of the pandemic, Italy adopted growing levels of restrictive measures, which ended with a 41-day lockdown from March 23 to May 3 2020. This action created a new kind of environment including a remarkable reduction of air, water and soil pollutants, together with a partial recovery of the ecosystems otherwise compromised. The presence of a permanent noise monitoring system made of 24 sensors installed in the city of Milan, allowed capturing the changes in the urban sound environment in a pre, during and post-lockdown period (months from February to June 2020). The comparison of the noise levels in terms of both absolute noise levels (Lden) and hourly noise profiles (median over lockdown period) with the same period of 2019, showed a dramatic reduction of the noise levels of approximately 6 dB. Splitting the contribution of all-non-traffic noises or anomalous noise events (ANE) from the recorded noise levels, we observe a greater contribution of the latter during the lockdown period. The use of DYNAMAP noise prediction system over an extended urban area allowed the evaluation of the population exposure to noise, estimating an increase of 14.9% and 16.4% of the exposed population to noises with Lden below 53 dB(A) and Lnight below 45 dB(A) with respect to 2019.

From March 23rd to May 3rd 2020, Italy underwent a complete lockdown in the attempt to contain the spread of the pandemic due to Covid-19 outbreak. During this period, a new kind of environment has been experienced in all cities, resulting in an abatement of traffic noise levels. Consequently, due to the prohibition of all non-essential activities, traffic noise dynamics changed as well. In this paper, we analyse the data recorded from the permanent noise monitoring network installed in the pilot area of the city of Milan, Italy. The results show how, besides a dramatic reduction of the noise levels (about 6 dB on average), also the noise pattern was profoundly changed. This is particularly important in the framework of DYNAMAP, a statistically based European project able to predict traffic noise over an extended area based on the noise recorded by limited number of monitoring stations. The change of the traffic dynamics, resulting in different noise patterns of the normalized hourly median profiles for each sensor, pose some limitations about the use of such predicting tool during extraordinary situations such as that experienced during a lockdown.

We studied the interaction of a double-spot laser beam with targets using the Prague Asterix Laser System (PALS) iodine laser working at 0.44 μm wavelength and intensity of about 1015 W/cm2. Shock breakout signals were recorder using time-resolved self-emission from target rear side of irradiated targets. We compared the behavior of pure Al targets and of targets with a foam layer on the laser side. Results have been simulated using hydrodynamic numerical codes.

The Environmental Noise Directive (END) requires that regular updating of noise maps is implemented every five years to check and report about the changes occurred during the reference period. The updating process is usually achieved using a standardized approach, consisting in collating and processing information through acoustic models to produce the updated maps. This procedure is time consuming and costly, and has a significant impact on the budget of the authorities responsible for providing the maps. Furthermore, END requires that simplified and easy-to-read noise maps are made available to inform the public about noise levels and actions to be undertaken by local and central authorities to reduce noise impacts. To make the updating of noisemaps easier and more cost effective, there is a need for integrated systems that incorporate real-time measurement and processing to assess the acoustic impact of noise sources. To that end, a dedicated project, named DYNAMAP (DYNamic Acoustic MAPping), has been proposed and co-financed in the framework of the LIFE 2013 program, with the aim to develop a dynamic noise mapping system able to detect and represent in real time the acoustic impact of road infrastructures. In this paper, after a comprehensive description of the project idea, objectives and expected results, the most important steps to achieve the ultimate goal are described.

Featured Application: The efficiency of temporal sampling of road traffic noise could be improved considering the stabilization time ST of the running equivalent level LAeq,ST, rather than referring to a fixed measurement time t, often used in common practice and chosen regardless of the amount of road traffic flow. In urban areas, noise levels can largely vary in space and time due to the great complexity of these environments. The time required for the fluctuations of the running equivalent level LAeq to be limited within a preset variability range is a key issue for determining a statistically representative sample of the urban acoustic environment. The goal of the present study is to evaluate the potential of the stabilization time, defined as the minimum time ST after which the difference between the corresponding continuous equivalent sound pressure level LAeq,ST and the continuous equivalent sound pressure level LAeq,T referred a longer time T, including ST, is never greater than a preset uncertainty interval ε. For this purpose, a dataset of road traffic noise continuously monitored in 97 sites in the city of Milan, Italy, is considered, providing 268 time series of 1 s short LAeq,1s, each lasting 24 h. The stabilization time ST referred the hourly LAeq,1h was determined for three preset uncertainty intervals ε, namely ±0.5, ±1.0 and ±1.5 dB(A). The results are promising and provide useful hints to obtain short-time noise monitoring as a statistically representative sample of the urban acoustic environment and, therefore, can be a tool to increase the low spatial resolution usually achievable by unattended permanent monitoring units. [ABSTRACT FROM AUTHOR]

To test the effect of imagery in the training of skilled movements, an experiment was designed in which athletes learned a new motor action and trained themselves for a month either by overt action or by mental imagery of the action. The experiment was carried out with 30 male karateka (M age=35 yr., SD=8.7; M years of practice=6, SD=3) instructed to perform an action (Ura-Shuto-Uchi) that they had not previously learned. The athletes were divided into three groups: Untrained (10 subjects who did not perform any training), Action Trained (10 subjects who performed Ura-Shuto-Uchi training daily for 16 minutes), and Mental Imagery (10 subjects who performed mental imagery training of Ura-Shuto-Uchi daily for 16 minutes). The subjects were tested five times, once every 7 days. During each test, they performed a series of 60 motor action trials. In Tests 1, 3, and 5, they also performed a series of 60 mental imagery trials. During the trials, an electroencephalogram (EEG), electromyography (EMG), muscle strength and power, and other physiological parameters were recorded. The results differed by group. Untrained subjects did not show significant effects. In the Action Trained group, training had an effect on reactivity and movement speed, with a reduction of EMG activation and reaction times. Moreover, muscle strength, power, and work increased significantly. The Mental Imagery group showed the same effects on muscle strength, power, and work, but changes in reactivity were not observed. In the Mental Imagery group, the study of Movement Related Brain Macropotentials indicated a progressive modification of the profile of the waves from Test 1 to Test 5 during imagery, showing significant variations of the amplitude of the waves related to the premotor and motor execution periods. Results show that motor imagery can influence muscular abilities such as strength and power and can modify Movement Related Brain Macropotentials, the profile of which potentially could be used to verify the effectiveness of motor imagery training.