The sounds were recorded using ultrasonic microphones by scientists in Israel.
その音は録音されました、超音波マイクを使って、イスラエルの科学者たちによって。
They placed tomato and tobacco plants inside a soundproof box and exposed them to various types of stress, such as water deprivation and stem snipping.
The group says it's unclear what leads to the sounds, but suspects they're created when water columns in dehydrated stems break down, generating air bubbles.