An auditory device assembly 1 comprises an earpiece 3 having an audio output device 7 for an ear 9 of a user and an audio processing unit 11, 31. The audio processing unit has a hearing-test mode and an audio streaming mode. In the hearing test mode it determines at least one ear characteristic of the ear of the user. In the audio streaming mode it outputs an audio stream via the audio output device. The audio output is adjusted based on the at least one ear characteristic determined in the hearing-test mode. The characteristic may be sensitivity of the ear to different frequencies. The device may include an ear-microphone 21 to detect sound emitted by the ear, such as otoacoustic emissions OAEs, which may be used to determine ear characteristics. The device may also include a pressure senor 23 to measure an aided and unaided sound pressure levels in the ear from which an ear characteristic may be determined.
