This article examines the status of hearing in the thought of Philo of Alexandria. I focus first on the Philonian physiology and psychology: my aim is to analyze how Philo conceives of the mechanism of auditory sensation, the place of hearing in the hierarchy of the senses and its teleological end, with a particular focus on what Philo’s perspective owes to Plato’s Timaeus. The evidence suggests that Philo systematically emphasizes the inferiority of hearing, which leads me in the second part to consider the relationship between the sense of hearing and the concept of πίστις (ie “credibility” as well as “faith”) and the philosophical and religious reasons that lead Philo to understand hearing as ἄπιστος. [http://pallas.revues.org/2723]