Town Hall Station, particularly at peak hour has always given me the creeps... so many people, such a confined space you'd hate to think of a bombing or fire or even an accident in which someone goes under a train...
Luckily since I changed jobs I dont have to get off at Town Hall but going through there it is the pits still - and I simply stay on board.
This article sums it up nicely.
And yes, the noise pollution from the "community service" announcements is horrendous as well and simply adds confusion.
If there was anywhere in Australia that was a disaster waiting to happen, its Town Hall.