Audio processing for a headworn device can include obtaining ear geometry of a user. A frequency response or transfer function can be determined, based on the ear geometry of the user and a model of the headworn device, where the frequency response or transfer function characterizes an effect of a path between a speaker of the headworn device and an ear canal entrance of the user on sound. An equalization filter profile can be generated based on the based on the frequency response or transfer function. The equalization filter profile can be applied to an audio signal, and the audio signal can be used to drive the speaker of the headworn device.