Dolphins lack vocal cords, nevertheless creating sounds: a complicated system of whistles, squeaks, moans, trills, and clicks are produced by sphincter muscles inside the blowhole.

海豚没有声带，但却能发声：一个由口哨声、吱吱声、呻吟声、颤音和咔嚓声组成的复杂系统是由喷水孔内的括约肌产生的。