Czech contrasts two trills: a “normal” alveolar apical trill, and a (probably) laminal trill with a much
greater tendency to frication and devoicing.
Following International Phonetic Association (1999, p.71), the latter is
transcribed [r̝].
ruka ("hand")
br̝ɛka ("river")
Audio Source
Illustrations of the IPA.
References:
International Phonetic Association (1999): Handbook of the International Phonetic Association: A Guide To The Use Of The International Phonetic Alphabet. Cambridge University Press.
