18. Audio documents reproduction apparatus according claim 13 ; wherein the apparatus comprises a means of representation of the documents in a space whose number of dimensions is equal to the number of audio parameters, and whose documents are associated with points disposed within this space, the means of determination of at least one document representing a group takes into account the distance between the equibarycentre of the points associated with the documents of the group and the point associated with this document.
18. Audio documents reproduction apparatus according claim 13 ; wherein the apparatus comprises a means of representation of the documents in a space whose number of dimensions is equal to the number of audio parameters, and whose documents are associated with points disposed within this space, the means of determination of at least one document representing a group takes into account the distance between the equibarycentre of the points associated with the documents of the group and the point associated with this document. 19. An audio documents reproduction apparatus according to claim 18 ; wherein the means of reproducing commences the reproducing of the identifiers with that whose point is closest to the barycentre of the points associated with the documents of the group, and thereafter those situated further and further away from the barycentre.