This is the 1763rd most frequent Polish word.
wiatru
"Of the wind."
"Wiatru" is in the genitive case in Polish, which is indicated by its use as the object of the noun "szum", implying the source or relation to 'wind'.
Szum wiatru uspokaja.
The sound of the wind calms.
Here, "wiatru" is also in the genitive case, following the preposition 'przed,' which governs the genitive when expressing protection from something.
Potrzebuję ochrony przed ostrym podmuchem wiatru.
I need protection from the sharp gust of wind.
"Wiatru" once again appears in the genitive case, showing possession relationship between the sound and the wind.