hēi gu lōng dōng
pitch-black
pitch-dark
黑
hēi
abbr. for Heilongjiang province 黑龍江|黑龙江[Hei1 long2 jiang1]
咕
gu
(onom.) for the sound of a bird, an empty stomach etc
隆
lōng
sound of drums
咚
dōng
(onom.) boom (of a drum)