With no explanation, label each line with "other-disease", "O", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
The
first
symptom
of
NIHL
may
be
difficulty
hearing
a
conversation
against
a
noisy
background
.
The:O
first:O
symptom:O
of:O
NIHL:other-disease
may:O
be:O
difficulty:O
hearing:O
a:O
conversation:O
against:O
a:O
noisy:O
background:O
.:O