AGM and attendees

Hi, I'm a long time reader and admirer, but this is my first question I couldn't find an answer for:

We are having our AGM in mid December and one owner has demanded that, although he will be in Victoria at the time on holiday (we are in NSW), that he can ‘teleconference’ in.  Is this a reasonable request?  I have not seen anything in the strata laws about this kind of thing, owners are either present or not present (and therefore have the option to provide a proxy with their wishes indicated).  Does an owner who is attending ‘by voice’ only have the same powers as one who is physically present?  If the ‘voice only’ owner has provided a proxy I’m guessing he couldn’t vote as well (by shouting down the telephone line!) ?