Invertebrate Ears and Hearing

Synonyms

Acoustic Sensillum; Auditory Sensillum

Definition

A cuticular sense organ (sensillum) containing a specialized Mechanoreceptor for transducing the particle velocity or pressure component of sound energy into electrochemical nerve impulses that are transmitted to the central nervous system (CNS) and which are used to mediate acoustically evoked behavior (e.g., detection and localization of mates, predators, prey or hosts).

Characteristics

Among invertebrates, a sense of hearing has been described only in arthropods. Except for a few species of Crustacea, members of the Insecta are the only invertebrates known to both produce and receive airborne sounds, and to use airborne acoustic signaling to mediate behavior. Some insect auditory organs, such as Trichoid Sensilla (Fig. 1a) or Johnston's Organs (Fig. 1b) are sensitive to the particle velocity component of sound, sometimes called near-field sounds. Particle displacement receivers are inherently directional because particle...