Wind noise at infrasonic frequencies and near-surface turbulent distortion

In atmospheric turbulence, multiple theories suggest that the wind noise reduction of a screened microphone should approach that of an unscreened microphone at a low wavenumber relative to the size of the windscreen. Typically, this wavenumber regime falls within the infrasonic frequency range. Contrary to existing theory, experimental data indicates that wind noise reduction occurs at low wavenumbers. It is hypothesized that near-surface turbulent distortion is the mechanism by which wind noise reduction is achieved at low wavenumbers. An overview of a theoretical model based on rapid distortion theory is discussed, as well as a recent outdoor experiment. Data were obtained for characterizing the near-surface turbulent distortion and internal pressures of windscreens in atmospheric turbulence. Comparisons between the rapid distortion theory model and experimental data are used to assess the validity of the proposed hypothesis.