The SMRT has recently started running some questionable campaign involving some announcement. The campaign appears to be targetting at people, telling them they should be more polite by standing away from the door, or from the hand poles, or talking softer on the handphone, and so on.
One of the more questionable things that TPTB has failed to realized is that sometimes, these voice-verts are run when the MRT is inside a tunnel. When that happens, due to wind resistance, the noise level inside the MRT is rather high, and still they're playing the voice-verts, which makes it very difficult to hear.
The most funny thing is, the noise level inside the MRT is rather high, which is why you have to practically yell into the handphone, unfortunately, these questionable voice-verts by the SMRT doesn't help.
Replace questionable with your favourite adjective. :o)