plants can hear the munching of predatory insects and then release defensive chemicals that make themselves taste less good or poison the oncoming predator- they can distinguish whether the approaching insect is a predator or not- by listening to the munching sound that the insect is making. Plants have a kind of Cilia on their leaves called Trichomes - they vibrate in response to the particle motion in the air, a sound, that mechanical reception is the mechanism by which they and other organisms like coral larvae can "hear sound" can receive the information in the sound, how they process that info is still a mystery, a fabulous mystery, every time we solve something we open up a new mystery. How do these tiny hairs, these Trichomes on the surface of the leaves selectively vibrate in the frequency range of the plants primary insect predator, how are they attuned? study of acoustic tuning between different plant species . there's a lot of interspecies comm going on in nature -karen bakker