Plants communicate with their environment in many ways, using colors and shapes and secreting chemicals. Yet, the possibility that plants emit airborne sounds that reveal their condition has not been investigated. Here, we develop a novel method for remotely detecting plant sound emission. We use it to demonstrate, to our knowledge for the first time, that plants emit sounds that can be recorded from a distance. We recorded ~65 dBSPL ultrasonic sounds at 10 cm distance from tomato and tobacco plants, suggesting that these sounds could be detected by many animals from up to several meters. We further train machine learning algorithms to identify the physiological condition of tomato and tobacco plants based solely on the emitted sounds. We successfully classified the plant's condition - dry, cut, or intact - based on its emitted sounds. Our results suggest that animals, and possibly even other plants, could use sounds emitted by plants to gain information about the plant's condition. More investigation on plant bioacoustics in general and on sound emission in plants in particular may open new avenues for understanding plants, and their interactions with the environment.