Acoustic allometry is the study of how animal vocalizations reflect their body size. A key aim of this research is to identify outliers to acoustic allometry principles and pinpoint the evolutionary origins of such outliers. A parallel strand of research investigates species capable of vocal learning, the experience-driven ability to produce novel vocal signals through imitation or modification of existing vocalizations. Modification of vocalizations is a common feature found when studying both acoustic allometry and vocal learning. Yet, these two fields have only been investigated separately to date. Here, we review and connect acoustic allometry and vocal learning across mammalian clades, combining perspectives from bioacoustics, anatomy and evolutionary biology. Based on this, we hypothesize that, as a precursor to vocal learning, some species might have evolved the capacity for volitional vocal modulation via sexual selection for ‘dishonest' signalling. We provide preliminary support for our hypothesis by showing significant associations between allometric deviation and vocal learning in a dataset of 164 mammals. Our work offers a testable framework for future empirical research linking allometric principles with the evolution of vocal learning.

声学异速生长是研究动物发声如何反映其体型的一门学科。这项研究的一个主要目的是识别声学异速原理的异常值，并查明此类异常值的进化起源。一项平行的研究调查了能够进行声音学习的物种，即通过模仿或修改现有发声来产生新声音信号的经验驱动能力。发声修改是研究声学异速生长和声乐学习时发现的一个常见特征。然而，迄今为止，这两个领域只是分别进行了研究。在这里，我们结合生物声学、解剖学和进化生物学的观点，回顾并连接哺乳动物进化枝的声学异速生长和声音学习。基于此，我们假设，作为声音学习的先驱，某些物种可能通过“不诚实”信号的性选择进化出了意志声音调节的能力。我们通过在 164 只哺乳动物的数据集中显示异速生长偏差和声音学习之间的显着关联，为我们的假设提供了初步支持。我们的工作为未来的实证研究提供了一个可测试的框架，将异速生长原理与声乐学习的进化联系起来。