title: The Lombard effect emerges early in young bats: implications for the development of audio-vocal integration.
abstract: Auditory feedback plays an important role in vocal learning and, more generally, in fine-tuning the acoustic features of communication signals. So far, only a few studies have assessed the developmental onset of auditory feedback. The Lombard effect, a well-studied audio-vocal phenomenon, refers to an increase in vocal loudness of a subject in response to an increase in background noise. Here, we studied the time course of the Lombard effect in developing bats,Phyllostomus discolorWe show that infant bats produced louder vocalizations in noise than in silence at an age of only 2 weeks. In contrast, the infant bats' morphology and vocalizations changed gradually until 2 months of age. Furthermore, we found that the Lombard magnitude, i.e. how much the bats increased their vocal loudness in noise relative to silence, correlated positively with the age of the infant bats. We conclude that the Lombard effect features an early developmental origin, indicating a fast maturation of the underlying neural circuits for audio-vocal feedback.
authors.affiliation: Max Planck Institute for Ornithology, Acoustic and Functional Ecology Group, Eberhard-Gwinner-Straße, Seewiesen 82319, Germany luojh135@gmail.com lutzw@lmu.de.|Division of Neurobiology, Department Biology II, Ludwig-Maximilians-Universität München, Großhaderner Straße 2, Planegg-Martinsried 82152, Germany.
authors.forename: Jinhong
authors.identifier: 0000-0002-2780-475X
authors.initials: J
authors.lastname: Luo
authors.affiliation: Division of Neurobiology, Department Biology II, Ludwig-Maximilians-Universität München, Großhaderner Straße 2, Planegg-Martinsried 82152, Germany.
authors.forename: Andrea
authors.initials: A
authors.lastname: Lingner
authors.affiliation: Chair of Zoology, Technische Universität München, Liesel-Beckmann-Street 4, Freising-Weihenstephan 85350, Germany.
authors.forename: Uwe
authors.initials: U
authors.lastname: Firzlaff
authors.affiliation: Division of Neurobiology, Department Biology II, Ludwig-Maximilians-Universität München, Großhaderner Straße 2, Planegg-Martinsried 82152, Germany luojh135@gmail.com lutzw@lmu.de.
authors.forename: Lutz
authors.initials: L
authors.lastname: Wiegrebe
mesh_terms: D000818:Animals; D002685:Chiroptera / Q000254:growth & development* / Q000502:physiology; D004455:Echolocation; D009622:Noise; D013016:Sound; D014828:Vocalization, Animal
keywords: Animal communication; Audio-vocal integration; Echolocation; Environmental noise; Signal plasticity