The evolution of the Lombard effect: 100 years of psychoacoustic research

TLDR

The paper reviews the literature on noise‑dependent vocal amplitude regulation, tracing the scientific and biological history of the Lombard effect and comparing findings across anurans, birds, and mammals to infer its phylogenetic origins. The authors compare vocal data from frogs, birds, and mammals to reconstruct the evolutionary trajectory of the Lombard effect as a basic acoustic communication mechanism in noisy environments. Evidence supports either convergent evolution in birds and mammals or a shared ancestral origin in all amniotes, the latter implying the Lombard effect evolved over 300 million years ago.

Abstract

Abstract On the occasion of the centenary of the discovery of the Lombard effect, we review the literature on noise-dependent regulation of vocal amplitude in humans and other animals. The article addresses the scientific and the biological history of the Lombard effect: first, it sketches the evolution of the study of the Lombard effect, and second it reflects on the biological evolution of the effect itself. By comparing the findings from anurans, birds and mammals, we try to trace back the phylogenetic origins of this basic vocal mechanism for acoustic communication in noise. The current evidence suggests two alternative parsimonious hypotheses: either the Lombard effect is the outcome of a convergent evolution in birds and mammals or it may be a synapomorphy of all amniotes. If the latter is true, then the Lombard effect would have evolved to maintain vocal communication in the presence of noise more than 300 million years ago.