I'm not sure of the nature of your disciplinary hearing (at work?) but where I work, the initial letter that is sent advising of the date/time of the hearing also states that should the person not turn up, the hearing will go ahead without them and a judgement will be made in their absence.
Yes, it depends whether you just chose not to turn up or whether you gave a really good reason why you could not be present. Sickness could be a good enough reason, but not just any old bout of coughing.
Good point buildersmate, I forgot to add that if they person contacts us in advance with a legitimate reason for not attending, the hearing will be rearranged.
If they just don't turn up then the hearing goes ahead without them.