The scientists first played the birds two recorded sounds that they likely had never heard before. One was a warning cry of an allopatric chestnut-rumped thornbill, a bird not native to Australia. The other was a computer-generated bird sound called " buzz" .

科学家首先向鸟了两种它们以前从未听过音。一种音是异域栗尾刺警告声，这种鸟不是澳大利亚本土。另一种音是电脑生成" 嗡嗡" 鸟叫声。