Voices Without Words: The Spectrum of Nonverbal Vocalisations

Nonverbal vocalisations are a fundamental part of human life. This review uses Tinbergen’s ethological framework to examine the functions, ontogenetic trajectories, evolutionary history, and underlying mechanisms of five types of vocalisations: cries, laughter, moans, screams, and sighs. By integrating insights from evolutionary biology and social psychology, we demonstrate how biological functions and social factors shape these vocalisations. The review discusses the relationship between acoustic properties and functions, highlighting the diverse roles vocalisations can play, including emotion regulation, social bonding, threat signalling, and fostering group cohesion. Tracing the development of vocalisations from infancy to adulthood emphasises the role of innate tendencies as well as delineating processes of social learning. We additionally examine how social context and cultural norms influence vocalisations and their interpretation. For each vocalisation type, we map their distinct nature and communicative potential: cries are crucial for survival and caregiving responses; laughter fosters social bonding and group cohesion; moans convey a wide range of internal states from pleasure to discomfort; screams serve as urgent alarms in critical situations; and sighs regulate emotions and signal shifts in emotional states. This review emphasises that both biological and social factors must be considered to fully understand nonverbal vocalisations.