Group leader : Nicolas Mathevon (Univ. Saint-Étienne & Institut universitaire de France)
Our research revolves around animal and human acoustic communication from both a proximate and an evolutionary point of view. We are interested in elucidating how environmental and social constraints shape communication. Deciphering interactions between association patterns and communication between individuals is mandatory to understand the evolution of social systems in Humans and animals. In spite of an increasing research effort over the past years, there are still gaps of knowledge concerning the processes that drive the organization of communication system in complex societies.
We propose a comparative and experimental view, developing an alliance between research on wild animals’ behaviour in the field and investigations in the laboratory. Our research goes along three axes : a phylogenetical axis with a comparative approach of communication systems throughout Vertebrates ; a trans-disciplinary axis by investigating processes at the brain level together with the behavioural level ; a social complexity axis by focusing on one end on “simple” communication and social systems found e.g. in some fish species and crocodiles, and on the other end on complex or highly complex ones (birds, marine mammals, apes and Humans).
See also The BioAcoustic Team
Acoustic communication in complex social contexts
The goal of this line of research is to understand how social organization represents an evolutionary force that shapes information coding by signalers and information integration by receivers. To get a comprehensive view, we investigate different biological models (birds, elephant seal, apes, humans) and explore the links between the nature of social bonds and communication processes. One aim is to develop our research on the Human baby’s non-verbal acoustic communication. We intend to precise the information content of Human babies’ cries, and to investigate factors (mostly gender and culture) influencing the perception and the behavioral response of adult listeners. Our approach is multi-disciplinary (acoustic signal analysis, playback experiments, brain imaging in collaboration with neuroscientists). Another project aims at studying how acoustic communications relate to the structure of the social network in birds. On one hand, we investigate the acoustic basis of the monogamous pairbond. Monogamous partners work as a team during chicks rearing and synchronize their activity. We investigate whether coordination between mates relates to the characteristics of intra-pair communication both within and between species (zebra finches, great tits, European dippers). On the other hand, we use passive recordings to identify acoustic parameters of the communal sound of a bird group that represent good proxies of the group’s social structure. Another project aims at decoding the system of vocal communication in great apes who live in complex social groups. We do playback experiments on mandrills and bonobos, both in captivity and in the wild.
Communication in extreme acoustic environments
One of the most exciting current challenges in the field of acoustic communication is to understand how complex sounds are recognized in natural environments. This process involves multiple tasks : sound source separation (localizing the relevant sound source among a background of other potentially relevant sounds), signal to noise enhancement (separating the signal from background noise such as environmental sounds) and signal categorization (cognitively classifying the signals to assign it a meaning). We focus on two biological contexts : communication in dense vegetation and in confusing environments. Specifically, we investigate auditory scene analysis in zebra finches. The zebra finch represents an interesting laboratory model to understand the neurophysiological processing of information encoded by noisy signals.
Evolution of information coding in communication signals
This line of research intends to integrate experiments and results obtained with a wide range of vertebrate models in order to test the respective weight of phylogenetical vs social and environmental constraints in signal shaping. Besides our investigations on birds and mammals, we work on acoustic communication in crocodiles (a group phylogenetically relative to birds) and fish. Specifically, we investigate the information content of crocodile juveniles’ vocalizations, searching for acoustic cues that modulate maternal behaviour. In fish, we are interested in the synergy between acoustic signals and the other communication channels during agonistic interactions between males.
Applied research : Spatial and temporal analysis of acoustic communication networks
This line of research aims at developing practical tools for the analysis and the assessment of animal populations through acoustic monitoring. By focusing on some bird species (mountaneous galliforms and birds of the tropical forest), we cross biological data (interactions through communication) and spatial positioning of the individuals.