“…The principal source of variability seems to be underlain by the fact that prelingually deafened adolescents or adults constitute a heterogeneous group of subjects who may differ from one another not only for duration of deafness, but also as regards variables which have been recognized as influencing cochlear implantation outcome such as etiology, residual hearing, mode of communication, speech therapy, education, device and strategy [Osberger et al, 1998;Schramm et al, 2002;Teoh et al, 2004a;Waltzman et al, 2002]. However, since the type of device has finally been recognized as not really influencing postimplant outcome [Teoh et al, 2004a] and obsolete strategies have not been used in recent studies, the observed variability in postimplant performances should mainly be attributed to the characteristics of patients 'per se'.…”