In the ancient world, the sense of hearing was upheld as the gateway to intellect and reason. Physicians and philosophers alike endeavoured intently to uncover the physical and metaphysical mysteries of hearing. This presentation will use ancient texts to illuminate the main theories of hearing, hearing loss and medical treatments during antiquity. Stoic philosophy adhered to the humoral theory first proposed by Hippocrates, in which health and disease were the result of the balance between the four ‘humours’ - blood (sanguinis), phlegm (pituita), yellow bile (chole) and black bile (melancholia). Hearing was thought to originate from the vibration of air through the spirit (pneuma) of the ear, which was sensed by the ruling faculty of the soul (hegemonikon) seated within the heart. This pathway was governed by divine reason. Hearing loss was considered to be caused by an imbalance of the humours or cosmic disruption of the pneuma. Conversely, Epicurean philosophy introduced the atomistic worldview, most thoroughly elucidated in Lucretius’ epic poem De Rerum Natura (‘On the Nature of Things’), and accounted for hearing as streams of particles (simulacra) striking the ear. There was no relationship with the divine. Hearing loss was caused by mechanical obstruction or inflammation of this pathway. Even as animal dissection began to reveal the intricate anatomy of the ear, hearing continued to be understood through these philosophical beliefs. Diseases of the ear and hearing were treated with a variety of concoctions and procedures to rebalance the humours and remove obstructions. These have been preserved in historical compilations and medical treatises written by Pliny the Elder, Scribonius Largus, Celsus and Galen.