Process for authenticating a user, to control his remote access to a service, data base or data network, wherein, in an enrolment step, an initial voice sample provided by the user is analyzed to obtain an initial user-specific voice profile and, in a later verification step, a current voice sample provided by the user is analyzed to obtain a current voice profile which is compared to the initial voice profile to generate an access control signal in response to the result of the comparison step, wherein additional user-dedicated authenticating means are generated in a pre-enrolment period, the additional authenticating means being used to authenticate the user in the enrolment step and/or in an access control step prior to and independent on the enrolment step, in a provisional or supplementary authentication procedure.