But, what i know, Polish language don`t have rule ``one letter, one voice``. Correct me if i`m wrong
As in many other languages, in Polish there are some elements of orthography that requires knowledge of etymology to justify its character. In Polish you should notice, among other irregularities, the combination of
rz, which most frequently represents the same sound, which is otherwise represented by
ż - the spelling reflects the historical difference.
The other orthographic distinction of
u and
ó also reflects etymology.
Orthographic
ch and
h are identically pronounced; though historically, one was voiceless the other voiced.
The letters with the acute accent -
ś, ź, ć, dź, ń - when used not before vowels, sound just as those
si, zi, ci, dzi, ni, when used before vowels.
The two consonants spelled
rz and
w become voiceless when preceded by
p,
k or
t.
Those are just a few exceptions to the ``one letter, one voice`` rule. There are many more, making Polish spelling not so easy thing to master.