An auditory prosthesis (14, 14′) is adapted for compensation of hearing loss and for sound pressure determination. During calibration of the sound field to be used during fine-tuning of the auditory prosthesis, the auditory prosthesis is positioned at an observation point in the sound field, and the sound pressure at the auditory prosthesis is adjusted based on determinations of sound pressures performed with the auditory prosthesis. Thus, the need for dedicated calibrated sound pressure determining equipment is eliminated. The invention provides an auditory prosthesis, a method and a system for calibration of a sound field.