Bioacustic

Many biological organisms use sound waves or vibrations for orientation or communication. Interestingly, apart from chemical signalling, much of animal communication depends on propagating waves, such as light, acoustic, electromagnetic waves. Evolutionarily, the reception and processing of the energy embedded in such waves is advantageous, as it allows for the gain of information about the environment, close by or distant.
In plants, sensory and communication research exists, yet is not as advanced and recognised. Existing evidence is enticing and calls for further investigation on the proximate, mechanistic question of how plants acquire and respond to acoustic information and further, demands the examination of ultimate, functional questions as to why such information bears adaptive value.
Because of the ease with which it transmits through the environment, sound can indeed offer a particularly effective transmission channel for short range signalling, possibly involved in modulating the swarm behavior of growing roots. For long range signalling, other functions related to resource finding, intra- and/or extra-specific competition or cooperation, and growth orientation and coordination within the substrate can be envisaged. Acoustic and vibrational energy has other distinct dynamic advantages; it enables rapid and temporally well-defined, transient signal structures and responses to stimuli. Sound generation is also energetically much cheaper, yet not costless, than the production of volatile allelochemical messengers commonly used by plants.