To me, whose way of doing things is to disguise my voice, to be told to audition for only one part brings up some logical points that bear discussion. Normally, I try out for several parts using a different voice for each on the assumption that the caster is smart enough to figure out that I can do one part with the voice that I auditioned for another (most are more than smart enough--in fact, I'm currently doing a part that I got by auditioning for a different part altogether). An audition such as this, however, does not allow for this. Further, it is difficult for me to audition if I don't know what kind of voice the caster is looking for. I, like a great many VA's, can change my voice to suit, within certain limits. The voice I used here is one that's somewhere between completely serious and completely comical. I'm going to use a similar voice in the part of the AI of a T.A.R.D.I.S. Yet, I have no way of knowing if this voice is what the part calls for, and no place to try a different voice, It would seem to me that this acts to limit the caster's options...but I'm just an amateur voice actor.