title: How minute sooglossid frogs hear without a middle ear.
abstract: Acoustic communication is widespread in animals. According to the sensory drive hypothesis [Endler JA (1993) Philos Trans R Soc Lond B Biol Sci 340(1292):215-225], communication signals and perceptual systems have coevolved. A clear illustration of this is the evolution of the tetrapod middle ear, adapted to life on land. Here we report the discovery of a bone conduction-mediated stimulation of the ear by wave propagation in Sechellophryne gardineri, one of the world's smallest terrestrial tetrapods, which lacks a middle ear yet produces acoustic signals. Based on X-ray synchrotron holotomography, we measured the biomechanical properties of the otic tissues and modeled the acoustic propagation. Our models show how bone conduction enhanced by the resonating role of the mouth allows these seemingly deaf frogs to communicate effectively without a middle ear.
authors.affiliation: Centre de Neurosciences Paris-Sud (CNPS), Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche (UMR) 8195, Université Paris XI, 91405 Orsay, France.
authors.forename: Renaud
authors.initials: R
authors.lastname: Boistel
authors.forename: Thierry
authors.initials: T
authors.lastname: Aubin
authors.forename: Peter
authors.initials: P
authors.lastname: Cloetens
authors.forename: Françoise
authors.initials: F
authors.lastname: Peyrin
authors.forename: Thierry
authors.initials: T
authors.lastname: Scotti
authors.forename: Philippe
authors.initials: P
authors.lastname: Herzog
authors.forename: Justin
authors.initials: J
authors.lastname: Gerlach
authors.forename: Nicolas
authors.initials: N
authors.lastname: Pollet
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Aubry
mesh_terms: D000818:Animals; D001001:Anura / Q000502:physiology*; D001696:Biomechanical Phenomena; D001844:Bone Conduction / Q000502:physiology*; D007758:Ear, Inner / Q000033:anatomy & histology*; D006309:Hearing / Q000502:physiology*; D008954:Models, Biological; D009055:Mouth / Q000033:anatomy & histology / Q000502:physiology; D017356:Synchrotrons; D014828:Vocalization, Animal / Q000502:physiology
keywords: X-ray imaging; audition; earless frog; extra-tympanic pathways