I pass Potong Pasir MRT Station everyday coming home from
school, and I agree with you, though I have never heard it while
passing Little India before.
Though I am more concerned that when passing by Woodleigh
Station, without fail, there will be an EXCESSIVELY LOUD and
annoying chime to remind us about the prohibition of eating
and drinking on the train or something of that sort.
When from Potong Pasir to Woodleigh that chime u talking about, is
the one which is actually in F# major(original, not
flattened)
as for the flattened tone in question, i guess that it is here
to stay since until now it is still not corrected.
my guess for why this thing happen(as nobody has
really mentioned about any reason), is because they edit the
clip to slow it down a bit. and if u decrease the speed of the
whole thing, the pitch is affected too. and the person who edit the
clip did not bother to separate the G major chime from the voice
which is suppose to be slowed down.
those with good ear can try to listen to the whole clip
carefully and see if there is any slight decrease in speed(or if
the voice of the announcer is somewhat lower in pitch). if not,
then my guess is wrong of course. this is the only possible reason
i can think of.
.