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" .

科学家首儿播放了两种它们以前从未听过的音。一种音是异域的栗尾刺嘴莺的，这种不是澳大利亚本土的。另一种音是电脑生成的" 嗡嗡" 叫。