As is well-known, in the measurement of low frequency sound, a main spectrum componentof the wind noise coexists almost within the same frequency bands as the lowfrequency sound. Accordingly, it is essentially difficult to eliminate this effect of windnoise only by using the analog filter based on the usual electrical cricuit. From theabove point of view, in this paper, a new trial of removing the above effect of wind noiseare proposed, especially, by focusing the dynamically computer aided algorithm of stateestimation. Concretely, this method is based on the principle of Bayes' filter. Finally, the effectiveness of the proposed state estimation method is experimentally confirmedtoo by applying it to the actual data of low frequency sound signal observed in a free sound field.