strange loop, strange trip

the PA squawks inaudible half-words
psychotic soundtrack to a subway ride
as senseless as the cawing of blackbirds
a vacuous unending phonic tide
was that announcement only in my head?
should I be up and exiting the car?
I struggle with a rising sense of dread
that I've already gone a stop too far
the Problem of Induction intercedes
I can't be certain of the words I hear
there may be no external aural feed
did that arise in mind? or in my ear?
each subway fare's a ticket through the brain
a opportunity to doubt you're sane