Personalised calibration methods and devices adapted to identify acoustical corrections to be applied for in-ear dosimetry. The acoustical corrections allow to convert a measured acoustic pressure within the ear-canal of a user to an equivalent acoustic pressure at the ear-drum and/or in free-field. The methods and devices also allow to distinguish noises originating from the user from noises of the environment in the ear occluded by an earplug. Such a distinction is done using two microphones to simultaneously measure the acoustic pressure within the ear-canal and outside the ear-canal. The device may be used to determine a cumulative sound pressure level dosage for which a user being exposed to surrounding sounds over a predetermined period of time.