Some C151 train are like that: DBG announcement from SOM (not
too sure)
*Chime* Next Station, Dhoby Ghaut Interchange. *Pause*
Passengers who are continuing their journey on the Circle Line or
North East Line, please alight at the next station. *6 seconds
later*
*Chime* Dhoby Ghaut Interchange. Passengers who are continuing
their journey on the Circle Line or North East Line, please alight.
*No Pause* Dhoby Ghaut Interchange. Please mind the platform
gap.
I like this 
http://www.youtube.com/watch?v=ahJ5YPYh07g
All trains liddat one