Single microphone wind noise reduction using techniques of artificial bandwidth extension

In this contribution, we propose a method to enhance single channel speech signals which are degraded by wind noise. In contrast to common speech enhancement systems, a special processing is required due to the highly non-stationary characteristics of wind signals. The basic idea is to exploit the fact that wind noise is mainly located at low frequencies and thus, a large frequency range of the speech is almost noise free. Techniques which artificially extend the bandwidth of telephone speech towards lower frequencies are applied to replace the highly disturbed low frequency parts. Here, the discrete model of speech production is used to reconstruct the required parts of the speech signal. Important parameters for this model are pitch frequency, the spectral envelope and a spectral gain. In this context, an evaluation is carried out which determines the robustness of several pitch estimators against wind noise. The frequency range of the reconstructed speech is finally adapted to the actual level of wind noise. Based on realistic scenarios it is shown that the influence of the wind noise can greatly be reduced by the proposed concept. This includes a comparison with a state-of-the-art speech enhancement system and an algorithm specially designed to reduce wind noise.