Pneuma of voice (phōnē)
Vocal extension — larynx / throat
The pneumatic extension of voice (phōnē). For the Stoics, the voice is the most direct evidence of cardiocentrism: the speaker feels the voice rise from the chest, not descend from the head. Chrysippus's argument (preserved by Galen, De placitis II.5) is roughly: 'we point to ourselves by striking the chest; the voice issues from the chest; therefore the I that speaks is in the chest.' The vocal extension passes from the hēgemonikon up through the trachea to the larynx, where breath is articulated into speech. We anchor the rendered point at the throat-centre landmark — the surface analogue of the larynx, where the vocal extension exits.
Point 8 of 9 in Stoic Hēgemonikon — Central Commanding Faculty + Seven Pneumatic Extensions
Cross-tradition overlaps
No overlapping points are registered for this point.
Sources
Diogenes Laertius, Lives VII.55, VII.157 (primary_canonical)
“Voice is air that has been struck, or is the proper object of the sense of hearing, as Diogenes the Babylonian says in his treatise On Voice.”
Galen, De placitis Hippocratis et Platonis II.5 (primary_canonical)
In De placitis Hippocratis et Platonis II.5 Galen reports Chrysippus' cardiocentric arguments, including the felt origin of voice in the chest and the gesture of striking the chest to indicate oneself. This is evidence for the chest-located hēgemonikon and its vocal extension, while Galen presents the argument polemically rather than endorsing it.