A method for calculating an estimated cumulative total sound dose reaching an ear of a user wearing an in-ear device substantially occluding a user's outer ear canal, the in-ear device including a speaker for providing an audio signal input from an audio output of an audio source inside the outer ear canal, an internal microphone for measuring a sound pressure level inside the occluded outer ear canal, and an external microphone for measuring an external ambient sound pressure level reaching the user's ear, said method comprising the steps of: - measuring, during a predetermined time interval (ΔT), the internal and external sound pressure levels, and the audio output; - performing an evaluation of the internal and external measured sound pressure levels; - calculating a current total sound dose from the internal sound pressure level and the audio signal input depending on the evaluation, a cumulative total sound dose based on a previous estimated cumulative total sound dose and the current total sound dose, and, based on a level of the audio signal input, a current interval estimated sound dose decrease (NDDR) so as to account for a fatigue recuperation of the user's ear over time, the current estimated sound dose decrease (NDDR) being subtracted from the cumulative total sound dose to obtain the current estimated cumulative total sound dose; and - controlling, based on the estimated cumulative total sound dose the audio input transmitted to the speaker; and being characterized by: the step of performing an evaluation including comparing, over the predetermined time interval (ΔT), the internal and external sound pressure levels to determine if both correlate and/or are coherent with one another, and if the external sound pressure level is larger than the internal sound pressure level by at least a predetermined level difference; and wherein the step of calculating includes calculating the current total sound dose from the audio signal input when the internal and external sound pressure levels do not correlate and/or are not coherent with one another, from the internal sound pressure level when the internal and external sound pressure levels correlate and/or are coherent with one another and when the external sound pressure level is not larger than the internal sound pressure level by at least the predetermined level difference, and from an addition of the audio signal input and the internal sound pressure level when the internal and external sound pressure levels correlate and/or are coherent with one another and when the external sound pressure level is larger than the internal sound pressure level by at least the predetermined level difference. - measuring, during a predetermined time interval (ΔT), the internal and external sound pressure levels, and the audio output; - performing an evaluation of the internal and external measured sound pressure levels; - calculating a current total sound dose from the internal sound pressure level and the audio signal input depending on the evaluation, a cumulative total sound dose based on a previous estimated cumulative total sound dose and the current total sound dose, and, based on a level of the audio signal input, a current interval estimated sound dose decrease (NDDR) so as to account for a fatigue recuperation of the user's ear over time, the current estimated sound dose decrease (NDDR) being subtracted from the cumulative total sound dose to obtain the current estimated cumulative total sound dose; and - controlling, based on the estimated cumulative total sound dose the audio input transmitted to the speaker; the step of performing an evaluation including comparing, over the predetermined time interval (ΔT), the internal and external sound pressure levels to determine if both correlate and/or are coherent with one another, and if the external sound pressure level is larger than the internal sound pressure level by at least a predetermined level difference; and wherein the step of calculating includes calculating the current total sound dose from the audio signal input when the internal and external sound pressure levels do not correlate and/or are not coherent with one another, from the internal sound pressure level when the internal and external sound pressure levels correlate and/or are coherent with one another and when the external sound pressure level is not larger than the internal sound pressure level by at least the predetermined level difference, and from an addition of the audio signal input and the internal sound pressure level when the internal and external sound pressure levels correlate and/or are coherent with one another and when the external sound pressure level is larger than the internal sound pressure level by at least the predetermined level difference.