lecturer 1 [ɕ] in isolation lecturer 2 [ɕ] in isolation lecturer 3 [ɕ] in isolation
Based on Maciołek & Tambor (2012)
Voiceless: the vocal folds are separated, not vibrating, the air flows freely between them.
Alveolo-palatal: the tongue blade gets close behind the alveolar ridge, the middle of the tongue gets close to the hard palate in the highest part of its vault. The lips are slightly rounded.
Fricative: there is a narrow passage between the articulators, the air from the lungs hits the edge of the passage and creates noise.