Ah, reading the start of your post...I guess I should have explained a little more clearly. The tomb of Nazarick is huge... The armoury, or to be more precise, the guild bank, wouldn't be on the same floor as the throne hall. Security and all that. So he wouldn't have heard her if he's in the bank. That being said, let's just say they used guild voice chat or something. :) Yay game logic. ^^

But yea, imagine each floor of the place being about as big as your average mansion. The throne hall takes up about half of the 4th floor. In order I would say it's arranged like this:

1st and 2nd: Offence and Defence. Basically the soldiers and siege equipment and such reside here. It's made up of two buildings with two floors each, surrounded by walls and the like. This is the only part of the tomb that's above ground.
3rd: The monster Arena. Strategically enemies would have to go through it and fight hordes of monsters before they could get to any good part of the tomb.
4th: The throne hall. It also has a large library with some crafting stations like spellcraft, alchemy and enchanting.
5th: Houses the servants. It also has a large kitchen, and a separate room with all kinds of other crafting stations. Woodworking, blacksmithing, etc.
6th: Intelligence/Information. This is basically the dungeon where prisoners were taken and where the spies and such operate from.
7th: This floor can only be teleported to by, or in the company of high ranking guild members. Such as our characters. It doesn't have a direct connection with the rest of the tomb for security reasons.