Caleb D Everett

The order of acquisition of consonants by children is impacted by both language-specific and species-wide factors. The latter factors also help to motivate the crosslinguistic commonness of some consonants. Here we explore the extent of overlap between crosslinguistic commonness and order of acquisition. We test how well the typological commonness of consonants is predictive of their order of acquisition in English, and vice versa, helping to shed light on the extent to which general cognitive and physical factors are explanatory vis-à-vis the acquisition of specific consonant types. We utilize several different sources to demonstrate that typological frequency and order of acquisition are indeed highly mutually predictive. We rely on acquisition data from English. We demonstrate that the crosslinguistic usage of a consonant is a better predictor of its order of acquisition than the language-specific factors tested.

We describe ongoing efforts to better understand the interaction of spoken languages and their physical environments. We begin by briefly surveying research suggesting that languages evolve in ways that are influenced by the physical characteristics of their environments, however the primary focus is on the converse issue: how speech affects the physical environment. We discuss the speech-based production of airflow and aerosol particles that are buoyant in ambient air, based on some of the results in the literature. Most critically, we demonstrate a novel method used to capture aerosol, airflow, and acoustic data simultaneously. This method captures airflow data via a pneumotachograph and aerosol data via an electrical particle impactor. The data are collected underneath a laminar flow hood while participants breathe pure air, thereby eliminating background aerosol particles and isolating those produced during speech. Given the capabilities of the electrical particle impactor, which has not previously been used to analyze speech-based aerosols, the method allows for the detection of aerosol particles at temporal and physical resolutions exceeding those evident in the literature, even enabling the isolation of the role of individual sound types in the production of aerosols. The aerosols detected via this method range in size from 70 nanometers to 10 micrometers in diameter. Such aerosol particles are capable of hosting airborne pathogens. We discuss how this approach could ultimately yield data that are relevant to airborne disease transmission and offer preliminary results that illustrate such relevance. The method described can help uncover the actual articulatory gestures that generate aerosol emissions, as exemplified here through a discussion focused on plosive aspiration and vocal cord vibration. The results we describe illustrate in new ways the unseen and unheard ways in which spoken languages interact with their physical environments.

Evidence is reviewed for widespread phonological and phonetic tendencies in contemporary languages. The evidence is based largely on the frequency of sound types in word lists and in phoneme inventories across the world's languages. The data reviewed point to likely tendencies in the languages of the Upper Palaeolithic. These tendencies include the reliance on specific nasal and voiceless stop consonants, the relative dispreference for posterior voiced consonants and the use of peripheral vowels. More tenuous hypotheses related to prehistoric languages are also reviewed. These include the propositions that such languages lacked labiodental consonants and relied more heavily on vowels, when contrasted to many contemporary languages. Such hypotheses suggest speech has adapted to subtle pressures that may in some cases vary across populations. This article is part of the theme issue ‘Reconstructing prehistoric languages’.

The sound systems of the world’s languages adapt to biomechanical, aerodynamic and cognitive pressures associated with sound production and discrimination. Such pressures help to yield the greater frequency of some sound types and the reduced frequency of others. In this paper I explore such adaptation, pointing out that sound systems not only adapt to such pressures in ways that are clear from a typological perspective, but that they adapt in more subtle ways that are only now becoming apparent. Furthermore, I survey a host of recent studies suggesting that sound systems likely adapt to some pressures that vary across populations and environments. While the extent of adaptation to such variable pressures is certainly debatable, the mere existence of phonetic/phonological adaptation to pressures that differ across populations is increasingly well supported. The evidence in support of such adaptation ranges from large-scale quantitative data, to biomechanical modeling, to the speech of Freddie Mercury.

Abstract We test the hypothesis that a specific anatomical feature, the dental malocclusion associated with reduced dental wear, causes languages to adapt by relying more heavily on labiodental consonants. In contrast to previous work on this topic, we adopt a usage-based approach that directly examines the relative frequency of such labiodental sounds within phonetically transcribed word lists and texts from thousands of languages. Labiodentals are shown to be very infrequent in the languages of hunter gatherers, who tend to have edge-to-edge bites as opposed to the overbite and overjet observed in populations that consume softer diets and rely heavily on eating utensils. This strong tendency is evident after controlling for Galton’s problem via multiple methods including frequentist and Bayesian linear mixed modeling. Additionally, we discuss data from Amazonian hunter gatherers with edge-to-edge bites. The languages of these populations are shown not to use labiodentals frequently, or to have only recently begun doing so. Finally, we analyze the speech of English speakers with varying bite types, demonstrating how the sounds used by individuals reflect the same phenomenon. The diverse findings converge on the same conclusion: speech adapts to anatomical differences within and across populations.

This work investigates whether reference in speech to certain quantities, namely 1, 2, and 3, is privileged linguistically due to our brain's native quantitative capacities. It is suggested that these small quantities are not privileged in specific ways suggested in the literature. The case that morphology privileges these quantities, apart from 1, is difficult to maintain in light of the cross-linguistic data surveyed. The grammatical expression of 2 is explained without appealing to innate quantitative reasoning and the grammatical expression of 3 is not truly characteristic of speech once language relatedness is considered. The case that 1, 2, and 3 are each privileged lexically is also difficult to maintain in the face of the global linguistic data. While native neurobiological architecture biases humans towards recognizing small quantities in precise ways, these biases do not yield clear patterns in numerical language worldwide.

Via an analysis of nearly 7000 phonetically transcribed word lists representing every major linguistic family, this study examines the frequency with which languages use particular consonants. The results suggest that there is an underlying global similarity in the frequency of occurrence of these consonants. Some consonants are uncommon across the word lists, and do not occur frequently even in those languages in which they are used. In contrast, a few other consonants represent a large portion of sounds in the word lists, across regions and linguistic families. The analysis quantifies the pervasiveness of such sounds that are known to be, impressionistically, common in speech. A new method captures the overall similarity of consonants’ rates of occurrence across languages and families. This method offers one means of evaluating the extent to which individual languages or families deviate from, or adhere to, the typical patterns of consonant usage. It is suggested that the crosslinguistic similarity of consonant usage, in terms of rates of occurrence in word lists, likely owes itself to previously documented factors like the relative ease of articulation of some sounds. This new evidence suggests that the role of ease of articulation in shaping speech may be more influential than generally assumed, though other explanatory factors are also likely at work and these patterns require further exploration with more robust intralinguistic phonetic corpora. •Languages are surprisngly similar in terms of how often they use many consonants.•This paper offers a novel method of evaluating the overall similarity of consonants' rates of occurrence across languages.•Ease of articulation- contributes to the inordinate frequency of some consonants.