Noise is still an unsolved problem of our time and influences the public health and well-being. So sound-exposure gains more and more in importance. This study examines the influence of turbulent vertical profiles of wind and temperature on the sound propagation, using the model SMART (sound propagation model of the atmosphere using ray-tracing). For several states of atmospheric stability, ten-minutetime series of vertical wind and temperature profiles were constructed and used as input data for the model. Simulations of the sound attenuation showed that turbulence affects the sound propagation in the atmosphere. This influence is reflected in a reduction of the sound attenuation level in the downwind area, whereas the sound shadow remains almost unaffected. The influence increases with the distance to the source and depends on the atmospheric stability. Beside the average influence due to turbulence, a “worst-case” scenario with the highest noise immission during the simulated time range was analyzed. Based on the results of this study, a new SMART-module, taking turbulence into account by parameterizations, was developed. The developed turbulence module is an upgrade of the sound model SMART and helps to improve the sound immission forecasts, including meteorological effects.

Acoustic travel-time measurement is a method for remote sensing of the atmosphere. The temperature-dependent sound speed as well as the flow field can be detected by measuring the travel time of a defined acoustic signal between a sound source and a receiver when the distance between them is known. In this study the properties of the flow field are reconstructed using reciprocal sound rays to separate the directionindependent sound speed from the effective sound velocity including the flow velocity component in direction of the sound path. The measurements are taken on a horizontal scale of about 2 m x 2 m. By measurements in interiors, where no flow of air exists, the temperature can be determined with an accuracy of 0.6°C and the flow component in direction of the sound path with an accuracy of 0.3 m/s. If flow of air exists the measurements gets complicated because the phase shifts, which have been detected by the receivers, cannot be corrected like it was possible without the influence of flow.