Calibration device and auditory prosthesis having calibration information

An auditory prosthesis (10), such as a hearing aid, containing a calibration device (8). The calibration device (8) comprises memory (28) in which is stored information which is characteristic of information intrinsic to the individual auditory prosthesis (10), the information being either information which represents a sufficient set of adjustment parameters (22) required to calculate the transfer function of the auditory prosthesis (10) or manufacturing information and a mechanism by which this information may be utilized by the auditory prosthesis (10) or by the programming system (32) of such auditory prosthesis.