(Image Source: Church History Library)
It hasn't changed much, although the original door has entirely been encased by glass and another door.
The chapel interior itself is fairly small, and there's no connected overflow. I'm sure they have the sound piped into other places when needed, though.
Also, the wood panels at the back of the chapel (below) look like they could have originally had a cry room. I'm fairly certain that's what it was--too bad it's not there anymore.