A method performed by an electronic device, includes: enabling first communication to a pair of headphones having first and second acoustic output transducers; enabling second communication to a first hearing device that has a first gain stage; communicating a band-limited portion of a first audio test signal via a second gain stage and via the first acoustic output transducer to the first hearing device while the first hearing device is in a first ear canal of a first ear, and communicating a band-limited portion of a second audio test signal via the second acoustic output transducer to an eardrum of a second ear; and determining a first gain value based on a gain value of the first gain stage and/or a gain value of the second gain stage, the first gain value being associated with the user's perception of equal loudness at both the first and second ears.