usually during the first round, the singers will hide their voices so that they wont be recognize easily. However, whn they do that the audience and judges will really judge based on that sound or voice. Thus, it will such a pity if the eliminated one actually sings really well using the real voice. Well, both are great singers, its just how the singers wants to sing in the first round. Usually if they pass the first round they will sing even better in the second round.