Sound pleasantness evaluation of pedestrian walks in urban sound environments

ICA 2016, 22nd International Congress on Acoustics, BUENOS AIRES, ARGENTINE, 05-/09/2016 - 09/09/2016The health benefits of a daily physical activity, and of walking in particular, are widely acknowledged. However, walking in urban environment inevitably leads to an increased exposure to noise, which forms a drawback of choosing this transportation mode. Being able to estimate the sound pleasantness associated with an urban walk trip has many potential applications, such as informing pedestrians about the sound along their intended walk, which may help them to optimize their route choice. In the past decade, various studies have focused on characterizing and estimating the sound pleasantness perceived at specific locations, on the basis of perceptive and physical measurements. However, to estimate the sound pleasantness along an urban walking trip, an additional step is required, which consists of assessing how a pedestrian evaluates the overall pleasantness of a sound environment that varies along the walking trip. In this work, the results of two laboratory experiments and one field experiment are discussed, which were designed to assess the overall evaluation of the sound environment along an urban walk. Physical and perceptive measurements at specified positions or continuously along a series of tested routes are available, in addition to a global evaluation of the route. A comparison between the results of the three experiments provides a rich source of information to understand how the sound pleasantness of a pedestrian walk is evaluated. The main conclusion is that for short walks (of about 1 minute), a recency effect is observed, which tends to disappear when the duration of the walk increases

Negotiating Race and Status in Senegal, Saint Domingue, and South Carolina: Marie-Adélaïde Rossignol and Her Descendants

This article tells the story of a young Charleston physician, John W. Schmidt Jr., whose medical license was revoked in 1831 because he was accused of being of “mixed blood.” The physician’s ancestry was unusual: his grandmother Marie-Adélaïde Rossignol Dumont was born in Gorée, West Africa; she was not a slave but a wealthy merchant who came to the United States in the 1790s via the French colony of Saint Domingue, which she left in the wake of the Haitian Revolution. The grandmother used various strategies of social and racial self-reinvention as she roamed the Atlantic world. Her acceptance into the Charleston elite was consistent with a traditional definition of race that was social and political rather than biological. The decision by the Medical Society of South Carolina to revoke her grandson’s license following a denunciation by a fellow refugee from Saint Domingue and fellow physician, Vincent LeSeigneur, was a manifestation of the rising “scientific racism” whose early advocates were members of the medical profession

Comparison of noise indicators in an urban context

Inter-Noise 2016, 45th International Congress and Exposition of Noise Control Engineering, HAMBOURG, ALLEMAGNE, 21-/08/2016 - 24/08/2016Noise is a major environmental issue, which gave birth in the last decades to the development of many engineering methods dedicated to both its estimation and mitigation. The specificity of the noise pollution problem lies in the complexity of human hearing and subjective assessment, and in the high spatiotemporal variation and rich spectral content of the noise generated by a wide variety of sources in urban context. Indicators that encompass all these dimensions are required for the description of sound environments and for the evaluation of noise mitigation strategies. This paper compares usual and more specific indicators, dedicated to environmental noise analyses, by means of a literature review. The comparison is based on the three following criteria: i) the ability of indicators to describe and physically categorize the urban sound environments, ii) the relevance of indicators for describing the perceptive appreciations of urban sound environments, iii) the ability of indicators to be estimated through classical or more advanced traffic noise estimation models. A discussion compares the pro and cons of the selected indicators in an operational scop

Exhumation of the ultra high-pressure Tso Morari unit in eastern Ladakh (NW Himalaya): a case study.

Exhumation processes of the ultra-high pressure (UHP) Tso Morari dome (NW-Himalaya) are investigated using structural, petrological and geochronological data. The UHP Tso Morari unit is bounded by the low-grade metamorphic Indus Suture Zone to the NE and Mata unit to the SW. Three deformation phases (D1, D2 and D3) are observed. Only D3 is common to the UHP unit and the surrounding units. In the UHP unit, the first deformation phase (D1) produced upright folds, under eclogitic conditions (> 20 kbar; 580 ± 60 °C). D1 is overprinted by D2 structures related to a NW-SE trending open anticline. This phase is characterized by blueschist mineral associations, and corresponds to the quasi-isothermal decompression from a depth of 90 km (eclogitic conditions) up to 30-40 km. The final exhumation phase of the Tso Morari unit is dominated by tectonic denudation and erosion (D3), associated with a slight temperature increase. Radiochronological analyses indicate that the UHP exhumation process began during the Eocene. Exhumation was fast during D1-D2 and slowed down through D3 in Oligocene time. The change in the deformation style from D1-D2 to D3 in the Tso Morari unit coincides with changes in the exhumation rates and in the metamorphic conditions. These changes may reflect the transition from an exhumation along the subduction plane in a serpentinized wedge, to the vertical uplift of the Tso Morari unit across the upper crust

Influence of experimental conditions on sound pleasantness evaluations

ICA 2016, 22nd International Congress on Acoustics, BUENOS AIRES, ARGENTINE, 05-/09/2016 - 09/09/2016Being able to characterize and estimate the urban sound perception is a key point to improve the city dwellers environmental quality. In the past decade, various studies have focused on collecting perceived global sound pleasantness at specific locations. Some of them were carried out on field in order to evaluate the soundscape perception of the participants directly in their context. Other studies were realized in laboratory to better control the stimuli and to increase the number of participants who were subjected to the same sound environment. Most of the laboratory experiments are done in large or semi-anechoic chamber with calibrated and highly realistic audio reproduction in order to respect the ecological validity of the experiment. On one hand, even with a high immersive level, the laboratory context is not as rich as the field context and the two types of experiment could lead to different results. On the other hand, few studies exist showing the influence of decreasing ecological validity for the same experience. This work presents a short statistical analysis of perceptive evaluations of ten urban locations under 4 different test conditions. First, evaluations are carried out directly in-situ in the city of Paris. Then audio-visual recordings of these locations are evaluated in three different experimental conditions: (i) in a well-controlled acoustic laboratory in Paris region with French people, (ii) in an acoustic laboratory in Buenos Aires with Argentinean participants and lowest immersive conditions, (iii) in a habitational room with Argentinean participants and subjective calibration. The study reveals that both the 'country' factor and the experimental conditions in laboratory do not show any significant impact on the perceived sound pleasantness and perceived loudness assessments

Data mining on urban sound sensor networks

ICA 2016, 22nd International Congress on Acoustics, BUENOS AIRES, ARGENTINE, 05-/09/2016 - 09/09/2016Urban sound sensor networks deliver megabytes of data on a daily basis so the question on how to extract useful knowledge from this overwhelming dataset is eminent. This paper presents and compares two extremely different approaches. The first approach uses as much as possible expert knowledge on how people perceive the sonic environment, the second approach simply considers the spectra obtained every time step as meaningless numbers yet tries to structure them in a meaningful way. The approach based on expert knowledge starts by extracting features that a human listener might use to detect salient sounds and to recognize these sounds. These features are then fed to a recurrent neural network that learns in an unsupervised way to structure and group these features based on co-occurrence and typical sequences. The network is constructed to mimic human auditory processing and includes inhibition and adaptation processes. The outcome of this network is the activation of a set of several hundred neurons. The second approach collects a sequence of one minute of sound spectra (1/8 second time step) and summarizes it using Gaussian mixture models in the frequency-amplitude space. Mean and standard deviation of the set of Gaussians are used for further analysis. In both cases, the outcome is clustered to analyze similarities over space and time as well as to detect outliers. Both approaches are applied on a dataset obtained from 25 measurement nodes during approximately one and a half year in Paris, France. Although the approach based on human listening models is expected to be much more precise when it comes to analyzing and clustering soundscapes, it is also much slower than the blind data analysis

Auditory sensory saliency as a better predictor of change than sound amplitude in pleasantness assessment of reproduced urban soundscapes

The sonic environment of the urban public space is often experienced while walking through it. Nevertheless, city dwellers are usually not actively listening to the environment when traversing the city. Therefore, sound events that are salient, i.e. stand out of the sonic environment, are the ones that trigger attention and contribute highly to the perception of the soundscape. In a previously reported audiovisual perception experiment, the pleasantness of a recorded urban sound walk was continuously evaluated by a group of participants. To detect salient events in the soundscape, a biologically-inspired computational model for auditory sensory saliency based on spectrotemporal modulations is proposed. Using the data from a sound walk, the present study validates the hypothesis that salient events detected by the model contribute to changes in soundscape rating and are therefore important when evaluating the urban soundscape. Finally, when using the data from an additional experiment without a strong visual component, the importance of auditory sensory saliency as a predictor for change in pleasantness assessment is found to be even more pronounced

Modeling soundscape pleasantness using perceptual assessments and acoustic measurements along paths in urban context

Mapping the pleasantness of an urban environment is an alternative approach, closer to the city dweller's perception, than standardized sound levels cartography. This study reports on modeling pleasantness in urban context using perceptual assessments and sound measurements for specific locations during an urban walk. These assessments have been collected from four groups of approximately ten participants on 19 different assessment locations, along a 2.1 km-long path traveled in both directions. Simultaneously, 1/3-octave band sound levels and audio were recorded. Perceptual and physical models of pleasantness are proposed for specific locations based on multiple linear regressions. A multilevel analysis was performed, and it is shown that a perceptual model that includes perceived loudness joined to the perceived time of presence of traffic, voices and birds explains 90% of the pleasantness variance due to the sound environment variations. Physical models that include the original acoustic indicators that are most correlated with perceptual variables explain 85% of this variance. Thanks to these models, a unique averaged pleasantness value is defined for each assessment location from the perceptual or physical collected assessments. The Pearson's correlation coefficient between the averaged perceived pleasantness and the modeled values from perceptual assessment reaches r(19) = 0.98, and r(19) = 0.97, with the modeled values from physical measurements. These results make it possible to consider the use of this kind of models in a cartographic context. As the path was traveled in both directions, the presentation-order effect has also been assessed, and it has been found that path direction did not have a significant impact on the pleasantness assessment at specific locations, except when very strong sound environment changes occurred. Finally, the study gives some insights about the retrospective global pleasantness assessment for urban walks. For very short walks between two assessment locations, a recency effect is shown. Nevertheless, this effect doesn't seem to be significant when longer routes are assessed

Probabilistic modelling of the temporal variability of urban sound levels

Relying on monitoring networks to compute or improve noise maps is an increasingly used approach. To be able to use this approach to provide adequate temporal treatments, a good understanding of the temporal variations within urban sound level time series is required. This paper provides an in-depth statistical analysis of the temporal characteristics of urban sound environments, on the basis of a wide measurement campaign during 8 month, at 23 measurement stations in Paris, which cover a large variety of urban sound environments. The time series of sound levels were recorded continuously with a 125 ms-time resolution, from which LA(50,1h) values were extracted. In total, 72 time-slots of interest are defined (24 1h-periods covering all days of the week). The statistical analysis determines for each station the Daily Average Noise Pattern (DANP), and for each of the 72 time-slots the 1h-Generalized Extreme Values distributions. The Generalized Extreme Values distributions are found to outperform the normal distributions to model the LA(50,1h) distributions. In addition, the average sound level differences between these 72 1h-time periods are calculated along with their variability, resulting in 72x72 delta matrices that describe the temporal relations between sound levels. This database is then used to develop two models, which aim to estimate DANP based on a limited amount of measurements. The model M1 relies on the delta matrices, whereas the model M2 consists of a weighted average of the DANP that are stored in the database in which the weights are based upon measures of similarity between the stations. Both models rely on probability density functions, and provide a measure for the reliability of the estimated noise levels. A test of both modelling approaches through simulated measurements shows that the model M1 seems to be more robust in case measurements are inaccurate. Beyond these two models, the proposed database could serve in the development of further models that aim to estimate sound levels based on a limited amount of measurements

Soil organic carbon pools across paired no-till and plowed Alfisols of central Ohio

No-till (NT) farming can restore the soil organic carbon (SOC) pool of agricultural soils, but the SOC pool size and retention rate can vary with soil type and duration of NT. Therefore, the objectives of this study were to determine the effects of NT and soil drainage characteristics on SOC accumulation across a series of NT fields on Alfisols in Ohio, USA. Sites under NT for 9 (NT9), 13 (NT13), 36 (NT36), 48 (NT48) and 49 (NT49) years were selected for the study. Soil was somewhat poorly drained at the NT48 site but moderately well drained at the other sites. The NT48 and NT49 on-station sites were under continuous corn (Zea mays), while the other sites were farmers' fields in a corn–soybean (Glycine max) rotation. At each location, the SOC pool (0–30 cm) in the NT field was compared to that of an adjacent plough-till (PT) and woodlot (WL). At the NT36, NT48 and NT49 sites, the retention rate of corn-derived C was determined using stable C isotope (13C) techniques. In the 0- to 10-cm soil layer, SOC concentration was significantly larger under NT than PT, but a tillage effect was rarely detected below that depth. Across sites, the SOC pool in that layer averaged 36.4, 20 and 40.8 Mg C/ha at the NT, PT and WL sites, respectively. For the 0- to 30-cm layer, the SOC pool for NT (83.4 Mg C/ha) was still 57% greater than under PT. However, there was no consistent trend in the SOC pool with NT duration probably due to the legacy of past management practices and SOC content differences that may have existed among the study sites prior to their conversion to NT. The retention rate of corn-derived C was 524, 263 and 203 kg C/ha/yr at the NT36, NT48 and NT49 sites. In contrast, the retention rate of corn-C under PT averaged 25 and 153 kg C/ha/yr at the NT49 (moderately well-drained) and NT48 (somewhat poorly drained) sites, respectively. The conversion from PT to NT resulted in greater retention of corn-derived C. Thus, adoption of NT would be beneficial to SOC sequestration in agricultural soils of the region