Noise due to ground transportation infrastructures is among the first environmental concerns of this beginning of 21th century. Building noise protections along motorways and railways is usually the chosen solution to reduce this noise. Currently, noise abatement systems used are mainly conventional ones: straight barriers, earth berms, tilted barriers, capped barriers. The purpose of this work is to propose innovative noise barriers using natural means and to study their acoustic performance by using numerical and experimental approaches. The numerical approach can also be coupled with an optimization tool, developed in this thesis, to obtain improved shapes of such devices using natural means. First, the main phenomena that appear during acoustic wave propagation in a complex outdoor medium are described. Then, a state of the art of the main noise barriers dedicated to ground transportation noise is achieved. It drives the choice of three innovative noise barriers using natural means. An analysis of the main numerical, experimental and optimization methods is carried out which allows to choose the methods adapted to our problem of noise barriers using natural means. The chosen methods are used in this work to assess the acoustic performance of the three innovative noise barriers. For the first chosen noise barrier called "gabions barrier", we perform in-situ and scale model measurements and numerical simulations. The results show a satisfactory efficiency of such noise devices. For the second and the third chosen noise barriers called respectively "sonic crystal assisted barrier" and "complex shaped earth berm", we perform a parametric numerical and an optimization studies. The results show the capacity of such noise devices to reduce motorways and railways noises in urban areas and they lead to improved shapes of innovative noise barriers using natural means.
