lecturer 1 [s] in isolation lecturer 2 [s] in isolation lecturer 3 [s] in isolation
Based on Maciołek & Tambor (2012)
Voiceless: the vocal folds are separated, not vibrating, the air flows freely between them.
Alveolar: the front part of the tongue gets close to the alveolar ridge and the teeth.
Non-palatalized: the middle of the tongue is in a neutral position, it does not take part in the articulation.
Fricative: there is a narrow passage between the articulators, the air from the lungs hits the edge of the passage and creates noise.