Czech ř (which continues the Proto-Slavic cluster *rj or *r
palatalised by a following front vowel) is a laminal alveolar trill [r̻] (the
correct IPA diacritic is a small subscript rectangle). As the tip of the tongue
vibrates, the blade of the tongue approaches the back of the alveolar ridge,
producing a fricative noise. The consonant is devoiced when preceded by a
voiceless obstruent or word-final.
Polish also had this sound until about the 17th century, when
it was replaced by [ʐ] (the voiceless allophone by [ʂ]), still spelt
<rz>. As one of my Czech colleagues once told me, a large proportion of
Czech children find the consonant extremely difficult to learn and even
some adults de-trill their ř, especially in word-final position, making it sound
like Czech š/ž.
Tell me if you can play the attached .rm file and if it sounds
all right. If there are any problems, I can post the original .wav file, which
ensures better sound quality, but is almost three times larger.
The file contains three Czech words in my non-native
imitation:
moře -- an element of nature, guess which
tři -- a low numeral, guess which
hřeben [ɦřɛbɛn] 'comb'
... and a prolonged ř in isolation
Piotr