Community Noise Survey Research Articles

Dose error impacts on a collection of realistic dose-response curves based on a NASA sonic boom community noise survey

The National Aeronautics and Space Administration (NASA) plans to conduct surveys of community response to quiet supersonic flight to collect dose-response data for international regulators. Previous models of noise dose versus annoyance response ignored uncertainty in the noise dose experienced by survey respondents. This dose error causes attenuation bias and results in inaccurate dose-response relationships. The impacts of dose errors can be explored by introducing error into the dose estimates of a simulated community noise survey. The simulated population annoyance response is determined by specific noise response characteristics, including the onset of annoyance intercept, rate of increasing annoyance, participant intercept variability, and response rates. This paper explores the effects of dose errors on notional populations created by perturbing the noise response characteristics observed in participants in a recent NASA flight test, Quiet Supersonic Flights 2018 (QSF18). The QSF18-based population parameters were shifted up to ±20% to create the study populations. For the anticipated dose range of the X-59, changes to the onset of annoyance intercept have the greatest impact on erroneous model results. Quantifying point estimate errors illustrates the impact of dose error, with errors up to 14 dB observed for a fixed high annoyance percentage.

Turbulence effects on shaped booms: Central composite design of modeled atmospheric turbulence parameters for sonic boom propagation

Propagation of sonic booms through turbulence reduces mean sonic boom perception metric levels and also causes considerable variability. NASA's PCBoom suite of sonic boom acoustic propagation modules includes an approximate method for accounting for the effects of turbulence on traditional N-wave sonic booms. The current implementation is ineffective for shaped sonic booms or low-booms, and it also has limited values for turbulence and ambient input parameters. NASA's future X-59 low-boom community noise surveys require an accurate estimate of the effects of turbulence in regions across the USA, so the module must be improved. This work presents the methods of selecting which ambient and turbulence parameters should be included in an improved PCBoom turbulence module. Turbulence and ambient data were collected from two atmospheric model databases, the Climate Forecast System Version 2 and European Centre for Medium-Range Weather Forecast Reanalysis Version 5 (ERA5), hourly from 7 AM to 7 PM local time for 10 years at 19 locations across the USA. A fully-factorial propagation analysis using these parameters would be exceedingly computationally expensive. Instead, a central composite design was chosen resulting in 45 combinations of ambient and turbulence parameters. These 45 cases effectively sample the space balancing computational burden.

Constructing noise-reaction questions for community noise surveys in nine different languages. Experiences and lessons learned

Studies of peoples’ reaction to community noise had been published since the early 1960ties, but differences in survey questions’ wordings had interfered with inter-survey comparisons. In 1993 an ICBEN team set the goal of creating high-quality survey questions that would yield internationally comparable measures of overall reactions to noise sources. After 7 years of discussions and research the team presented their recommendations. This paper presents some of the issues that were discussed by the ICBEN team and describes how they were dealt with.

Updated noise dose range of NASA’s X-59 aircraft estimated from propagation simulations

A follow-on study to Doebler and Loubeau [“The noise dose range of the X-59 estimated from propagation simulations,” JASA 150(4), A208 (2021)] is described. In the previous work, propagation simulations of NASA’s X-59 sonic thump were conducted using two near-field pressure solutions from NASA’s Cart3D computational fluid dynamics (CFD) code. The near-fields were propagated through realistic atmospheric profiles from the Climate Forecast System Version 2 database across the USA, and perceived level statistics of the thumps were presented. The current work repeats the previous analyses, instead using near-field CFD solutions from NASA’s Fully Unstructured Navier-Stokes (FUN3D) code for the same aircraft conditions (Mach 1.4 at 53 200 feet and Mach 1.3 at 43 000 feet), which achieve the minimum and maximum cruise loudness. NASA and contractors in the X-59 development and community noise testing project mutually agreed upon using FUN3D for generating near-field pressures. Sonic thump loudness statistics using the FUN3D near-fields are similar to those of Cart3D. The min loudness condition is about 1 dB (PL) greater when using the FUN3D solution, and the max loudness condition results are nearly identical. Understanding the X-59’s dose range for various flight and atmospheric conditions is important for planning X-59 community noise surveys.

Simulation and Regression Modeling of NASA’s X-59 Low-Boom Carpets Across America

NASA’s X-59 aircraft is predicted to produce a significantly quieter cruise sonic boom than traditional -wave-producing aircraft. A propagation simulation study was undertaken to quantify loudness levels, exposure size, and variability of the X-59’s low-boom carpet using realistic atmospheric profiles across the contiguous United States of America (CONUS). Near-field pressure data of the X-59 in supersonic cruise from NASA’s fully unstructured Navier–Stokes three-dimensional (known as FUN3D) computational fluid dynamics code were propagated using NASA’s PCBoom code, which solves an enhanced Burgers equation along acoustic rays. Atmospheric profiles from the National Oceanic and Atmospheric Administration’s Climate Forecast System Version 2 database were used for propagation at 138 locations across the CONUS. Carpets at each location were generated for aircraft headings in the four cardinal directions. Over one million X-59 carpets were generated in total. The effects of the heading, season, geography, and climate zone on boom levels and exposure size are presented. Multiple linear regression models were developed to estimate carpet width and loudness metrics across the CONUS. These results inform regulators and mission planners on expected variations in boom levels and carpet extent from atmospheric variations. Understanding potential carpet variability is important when planning community noise surveys using the X-59.

Experiment design considerations for longitudinal community noise surveys

NASA is planning community noise surveys in the coming years to collect data that might enable the return of overland supersonic flight. Community noise surveys are typically cross-sectional, with only a single response per respondent. However, to determine community response to individual supersonic over flights, longitudinal surveys with repeated responses per respondent are more practical. The downside of repeated responses is the potential for response bias, such as a carryover effect in which previous test conditions affect current behavior. Subjective sonic boom listening test data collected at NASA Langley Research Center were reanalyzed to look for evidence of carryover effects. Initial results do not suggest strong carryover effects. This presentation will provide results and suggestions for experiment design of future community surveys.

The noise dose range of the X-59 estimated from propagation simulations

NASA’s X-59 aircraft will soon be flown in a series of low-boom community noise surveys across the USA. Community test experimental designs will include noise dose schedules, which require an estimate of the noise dose range that X-59 can produce. To determine the dose range, propagation simulations using NASA’s PCBoom code were completed using CFD-generated X-59 C612A near-field pressure data for an on-design condition (Mach 1.4 at 53 200 ft) and two off-design conditions (Mach 1.4 at 46 000 ft and Mach 1.3 at 43 000 ft). Near-field data at four cardinal aircraft headings were propagated through one year of realistic atmospheric profiles from the Climate Forecast System Version 2 database at several USA locations. Statistics of the mean and range of the Perceived Level (PL) of the booms in the inner 40 km of each carpet as well as the carpet width were computed. Results indicate the typical inner carpet mean PL is approximately 70–87dB depending on the aircraft condition. The typical PL range across the inner carpet is 6–8 dB (on-design) and 5–13 dB (off-designs). The carpet widths ranged from 32–55 km. Understanding these quantities for various flight and atmospheric conditions is important for planning X-59 community noise surveys.

Comparing two statistical models for low boom dose-response relationships with correlated responses

This study compares two statistical modeling approaches to construct summary dose-response curves for low boom community noise surveys. NASA field survey data were used that consist of multiple responses from a survey participant. These data require an approach that accounts for the correlation among repeated annoyance observations from the same participant. A multilevel model accounts for the correlation by allowing estimated parameters to vary with each survey participant. On the other hand, a population average model utilizes generalized estimating equations and accounts for the correlation via a user-specified within-subject correlation structure. A visual comparison of the dose-response curves for these two methods reveals similar results. When comparing specific points along the summary curves, the multilevel model yields more precise confidence bounds than the population average model. The similarity between the summary curves derived from each model lends validity to both approaches for approximating a population representative summary curve.

The effect of modeling dose uncertainty on low-boom community noise dose-response curves

In logistic dose-response modeling, failing to account for uncertainty in estimated doses can cause an artificial flattening or attenuation of the slope of the summary curve. In Lee et al. [J. Acoust. Soc. Am. 147(4), 2222–2234 (2020)], data from two NASA low-amplitude sonic boom community noise survey tests were modeled using a Bayesian multilevel logistic regression (MLR) statistical model that assumed there was no uncertainty in the noise dose estimates. However, in these community tests, the noise dose uncertainty was estimated by Page et al. (NASA/CR-2014-218180 and NASA/CR-2020-220589/Volume I) using a leave-one-out method. In the current work, a term was added to extend the Bayesian MLR model to account for the estimated noise dose uncertainty quantified in the analyses of Page et al. This uncertainty term was included in two ways, either as classical or as Berkson uncertainty, and yielded similar results. When the uncertainty is accounted for in the Bayesian MLR model, the dose-response curves become 5%–10% steeper, but the difference in the noise dose that elicits a 5% highly annoyed response is small (less than 1 dB). This result is encouraging for future X-59 community tests whose survey area will be sparsely populated with noise monitors.

A community noise survey in Southwest Detroit and the value of supplemental metrics for truck noise

Noise exposure can affect sleep, health and cognitive performance, and it disproportionately affects communities of color. This study has the objective of evaluating both conventional and supplemental noise metrics in a community noise survey examining Southwest Detroit, Michigan, a densely populated and industrialized area with extensive truck traffic on residential streets. Sound pressure level (SPL) monitors were deployed at 21 residential sites within 900 m of a major interstate highway. With assistance from youth volunteers, continuous SPL measurements were obtained for 1.5–7 days at each site, and short-term vehicle counts on local roads were recorded. We calculated conventional noise metrics, including the day-evening-night average sound level LDEN and the 90th percentile 1-hr maximum L10(h), and evaluated the effect of distance from highways, traffic volume, time-of-day, and other factors. Supplemental metrics potentially appropriate for intermittent traffic noise were calculated, including fraction of time over specific SPL thresholds using a new metric called FDEN, which is the fraction of time over 60, 65 and 70 dB during night, evening and daytime periods, respectively, and a peak noise metric called L2P(h), which utilizes the 98th percentile SPL within time blocks to increase robustness. The conventional metrics indicated five sites that exceeded 70 dB, and the highest noise levels were found within ~50 m of truck routes, arterials and freeway ramps. The estimated impact of truck traffic ranged up to 17 dB for hourly averages and to 33 dB for 1-s peaks. The conventional metrics did not always capture short-term noise exposures, which may be especially important to annoyance and sleep issues. In addition to showing widespread exposure to traffic noise in the study community that warrants consideration of noise abatement strategies, the study demonstrates the benefits of supplemental noise metrics and community engagement in noise assessment.

Simulated X-59 on- and off-design sonic boom levels in realistic atmospheres for noise dose range estimation

NASA is planning several community noise surveys across the USA using the X-59 low-boom aircraft. These surveys require a range of noise levels to resolve a dose-response relationship. The X-59 was designed to produce a shaped sonic boom with a Stevens’ Perceived Level (PL) of 75 dB or less across the boom carpet in a standard atmosphere. However, the X-59’s flight condition can be adjusted to produce levels other than 75 PLdB to obtain a range of doses during community testing. Simulated nearfield pressure waveforms of the X-59 C612A in its on-design condition (Mach 1.4 at 53 200 ft) and an off-design condition at a lower altitude (Mach 1.4 at 46 000 ft) were propagated using PCBoom through realistic atmospheres over the span of one year at several locations across the country. The predicted on-design and off-design boom levels and carpet widths are presented, resulting in a preliminary estimate of the dose range that the X-59 may produce. Future work is planned with additional off-design conditions to assess the true capable dose range of the X-59.

Simulations of X-59 low-booms propagated through measured atmospheric profiles in Galveston, Texas

During NASA's Quiet Supersonic Flights 2018 (QSF18) test, residents of Galveston, Texas and surrounding communities were exposed to low amplitude sonic booms for a community noise survey. Despite the flight test lasting only 11 days, substantial weather variability occurred including snow and record high temperatures. Similar atmospheric variability could occur in future community noise flight tests with the X-59 Quiet Supersonic Technology aircraft that is currently being constructed. X-59 is designed to have a Stevens Mark VII Perceived Level (PL) of 75 dB in a standard atmosphere. In this work, X-59's low-boom performance in real atmospheres was tested by using NASA's PCBoom code to simulate propagation of its nearfield pressure through the atmospheric profiles measured during QSF18. Results indicate undertrack booms would not exceed 75 PLdB in these atmospheres. A range of about 8.5 PLdB between the loudest and quietest undertrack boom was observed indicating adjustments to the X-59 flight condition may be needed to achieve target loudness levels during future sonic boom community noise surveys. Attenuation rate, ray tube area, path length and other quantities throughout propagation of the loudest and quietest booms are presented, which indicate humidity differences below 15kft were a primary driver of the PL differences.

Traffic-Noise Assessment at Rush Hours in Quetta City

Noise is an environmental stressor, which leads to various ailments due to the physiological and psychological stresses it creates. It is essential to understand and evaluate the contributing factors of environmental noise, especially in densely polluted areas near major roads, railways and airports, for public health policy and planning. Noise level measurement permits precise and scientific analysis of noise annoyance, and therefore, this study aimed to determine the average noise levels of Quetta city. Seventy-three (73) location’s equivalent noise levels (Leq) were measured at peak rush hours for three consecutive days. Selected areas for measurement included health care centres, educational centres, government offices, public places, residential and commercial areas. All the selected sites were located near to main roads, where the traffic noise was the most prominent noise source. Noise was measured through calibrated microprocessor sound level meter. The results were computed by taking the mean of the three readings. The results showed 74 dBA as average noise level of Quetta city. It has been found that 90% of the selected locations in Quetta city exceeded the 65dBA, while 10 % of the total locations ranged between 55 to 65 dBA. The average noise exposure of the Quetta city was greater than the permissible international noise standard. This study identified the main traffic hubs of Quetta city, which requires mitigation strategies by the policy makers specifically for Health care and Educational sectors. It also requires adequate updated plans for community noise survey and ordinance.

Traffic-Noise Assessment at Rush Hours in Quetta City

Noise is an environmental stressor, which leads to various ailments due to the physiological and psychological stresses it creates. It is essential to understand and evaluate the contributing factors of environmental noise, especially in densely polluted areas near major roads, railways and airports, for public health policy and planning. Noise level measurement permits precise and scientific analysis of noise annoyance, and therefore, this study aimed to determine the average noise levels of Quetta city. Seventy-three (73) location’s equivalent noise levels (L eq ) were measured at peak rush hours for three consecutive days. Selected areas for measurement included health care centres, educational centres, government offices, public places, residential and commercial areas. All the selected sites were located near to main roads, where the traffic noise was the most prominent noise source. Noise was measured through calibrated microprocessor sound level meter. The results were computed by taking the mean of the three readings. The results showed 74 dBA as average noise level of Quetta city. It has been found that 90% of the selected locations in Quetta city exceeded the 65dBA, while 10 % of the total locations ranged between 55 to 65 dBA. The average noise exposure of the Quetta city was greater than the permissible international noise standard. This study identified the main traffic hubs of Quetta city, which requires mitigation strategies by the policy makers specifically for Health care and Educational sectors. It also requires adequate updated plans for community noise survey and ordinance.

Traffic-Noise Assessment at Rush Hours in Quetta City

Noise is an environmental stressor, which leads to various ailments due to the physiological and psychological stresses it creates. It is essential to understand and evaluate the contributing factors of environmental noise, especially in densely polluted areas near major roads, railways and airports, for public health policy and planning. Noise level measurement permits precise and scientific analysis of noise annoyance, and therefore, this study aimed to determine the average noise levels of Quetta city. Seventy-three (73) location’s equivalent noise levels (L eq ) were measured at peak rush hours for three consecutive days. Selected areas for measurement included health care centres, educational centres, government offices, public places, residential and commercial areas. All the selected sites were located near to main roads, where the traffic noise was the most prominent noise source. Noise was measured through calibrated microprocessor sound level meter. The results were computed by taking the mean of the three readings. The results showed 74 dBA as average noise level of Quetta city. It has been found that 90% of the selected locations in Quetta city exceeded the 65dBA, while 10 % of the total locations ranged between 55 to 65 dBA. The average noise exposure of the Quetta city was greater than the permissible international noise standard. This study identified the main traffic hubs of Quetta city, which requires mitigation strategies by the policy makers specifically for Health care and Educational sectors. It also requires adequate updated plans for community noise survey and ordinance.

Bayesian statistical models for community annoyance survey data

This paper demonstrates the use of two Bayesian statistical models to analyze single-event sonic boom exposure and human annoyance data from community response surveys. Each model is fit to data from a NASA pilot study. Unlike many community noise surveys, this study used a panel sample to collect multiple observations per participant instead of a single observation. Thus, a multilevel (also known as hierarchical or mixed-effects) model is used to account for the within-subject correlation in the panel sample data. This paper describes a multilevel logistic regression model and a multilevel ordinal regression model. The paper also proposes a method for calculating a summary dose-response curve from the multilevel models that represents the population. The two models' summary dose-response curves are visually similar. However, their estimates differ when calculating the noise dose at a fixed percent highly annoyed.

Multilevel modeling and regression as applied to community noise annoyance surveys

Tolerance to noise varies between communities, and between individuals comprising the communities. A multilevel modeling approach is useful for capturing such individual- and community-level variations. Here, we consider a model in which the community-level variations are sampled explicitly with community noise surveys, while the individual-level variations are sampled only in a statistical sense (i.e., hidden). The community-level variations are specifically quantified by the community tolerance level (CTL) [Fidell et al., J. Acoust. Soc. Am. 130(2), 791-806 (2011)]. Simulations based on the multilevel model indicate that the community- and individual-level variations have distinct statistical signatures, both of which are evident in noise annoyance surveys involving transportation noise. The annoyance curve for a previously unsurveyed community depends on the mean and variance of the CTL, and the sum of the hidden variances in noise tolerance and exposure among individuals in the community. Regression analyses of transportation noise annoyance using a multilevel, generalized linear model (GLM) enable noise tolerances and their variations at the two model levels to be distinguished and quantified.

CTL—A useful tool for inter-survey comparisons

The concept of Community Tolerance Level was presented in 2011 and in subsequent analyses the CTL has proven to be a useful tool for comparing results from different surveys on noise annoyance. The CTL provides a robust single-number description of the prevalence of annoyance in a community noise survey. It has been shown that accurate predictions of the prevalence of highly annoyed residents can be achieved by relatively few survey interviews as the selection of respondents does not have to cover the whole range of exposure. A re-analysis of existing studies on aircraft noise annoyance has shown that there has been virtually no change in people's response to this type of noise over the past 50 years, but there is a distinct difference in the response depending on the rate of which the noise situation has been changing. A similar analysis of results on road traffic noise from surveys conducted over a period of more than 50 years, will be presented.

Romanian Standardized Noise Reaction Questions for Community Noise Surveys

Romanian Standardized Noise Reaction Questions for Community Noise Surveys

Community noise survey of the city of Valdivia, Chile

A noise map of the city of Valdivia is created as a way to evaluate the noise of the city. This is a process that is usually associated with high operative costs. Some statistical techniques have been employed that have allowed the extrapolation of some measured values to assess noise at different times of the year, including “off” days thus reducing time and costs. The day–evening–night level L DEN is used as the rating method to describe long-term annoyance. In conclusion, the noise pollution in the city is widespread throughout most of its streets area, where measured noise values are similar to those commonly observed in cities that do not have mitigation programs and whose road traffic is their principal noise generation source.