The current paper presents an acoustic study of Lower Sorbian. Four native speakers of Lower Sorbian participated in this study. Center of gravity, standard deviation, skewness, kurtosis and slope measures were taken to measure the fricatives' spectral qualities. Vocalic transitions were also taken to gather finer grained information about the sibilants' articulation. The results indicated there is a three-way contrast in Lower Sorbian. The alveolar and retroflex segments have approximately the same place of articulation, but the overall tongue shape contributes significantly to the difference in spectral properties. The alveolopalatal segment is composed of a tongue-palate contact which extends from the dental place towards the palatal. This suggests that the length of the constriction also greatly affects the spectral properties of the fricatives. However, the phonetic realization of these segments is not the same as in Polish. The COG measures indicate both the Lower Sorbian retroflex and alveolopalatal segments is much lower than Polish. This suggests that the phonetic instantiation of the three-way contrast is variable. The results also indicate that the acoustic-perceptual cues from the vowel transitions and fricative spectra work in conjunction to distinguish the sibilants because no single cue is reliable enough to distinguish all of them.
Bibliographic reference. Howson, Phil (2015): "An acoustic examination of the three-way sibilant contrast in lower sorbian", In INTERSPEECH-2015, 2670-2674.