口哨儿

HSK 7-9

kǒushàor

whistle; whistle blow (also: to whistle)

他吹了一声口哨儿

tā chuī le yì shēng kǒushàor

He whistled once.

口哨儿一响大家集合

kǒushàor yì xiǎng dàjiā jíhé

As soon as the whistle sounds, everyone gathers together.