Functional load and the lexicon: Evidence that syntactic category and frequency relationships in minimal lemma pairs predict the loss of phoneme contrasts in language change

The effects of lexical frequency and homophone neighborhood density on incomplete tonal neutralization

We investigated the effects of lexical frequency and homophone neighborhood density on the acoustic realization of two neutralizing falling tones in Dalian Mandarin Chinese. Monosyllabic morphemes containing the target tones (Tone 1 and Tone 4) were produced by 60 native speakers from two generations (middle-aged vs. young). The duration of tone-bearing syllable rhymes, as well as the F0 curves and velocity profiles of the lexical tones were quantitatively analyzed via linear mixed-effects modeling and functional data analysis. Results showed no durational difference between T1 and T4. However, the F0 contours of the two falling tones were incompletely neutralized for both young and middle-aged speakers. Lexical frequency showed little effect on the incomplete tonal neutralization; there were significant differences in the turning point of the two falling tones in syllables with both high and low lexical frequency. However, homophone neighborhood density showed an effect on the incomplete neutralization between the two falling tones, reflected in significant differences in the slope and turning point of the F0 velocity profiles between the two tones carried by syllables with low density but not with high density. Moreover, homophone neighborhood density also affected the duration, the turning point of F0 curves, and velocity profiles of the T1- and T4-syllables. These results are discussed with consideration of social phonetic variations, the theory of Hypo- and Hyper-articulation (H&H), the Neighborhood Activation Model, and communication-based information-theoretic accounts. Collectively, these results broaden our understanding of the effects that lexical properties have on the acoustic details of lexical tone production and tonal sound changes.

Languages are efficient, but for whom?

Human languages evolve to make communication more efficient. But efficiency creates trade-offs: what is efficient for speakers is not always efficient for comprehenders. How do languages balance these competing pressures? We focus on Zipf's meaning-frequency law, the observation that frequent wordforms have more meanings. On the one hand, this law could reflect a speaker-oriented pressure to reuse frequent wordforms. Yet human languages still maintain thousands of distinct wordforms, suggesting a countervailing, comprehender-oriented pressure. What balance of these pressures produces Zipf's meaning-frequency law? Using a neutral baseline, we find that frequent wordforms in real lexica have fewer homophones than predicted by their phonotactic structure: real lexica favor a comprehender-oriented pressure to reduce the cost of frequent disambiguation. These results help clarify the evolutionary drive for efficiency: human languages are subject to competing pressures for efficient communication, the relative magnitudes of which reveal how individual-level cognitive constraints shape languages over time.

How the Probabilistic Structure of Grammatical Context Shapes Speech

Does systematic covariation in the usage patterns of forms shape the sublexical variance observed in conversational speech? We address this question in terms of a recently proposed discriminative theory of human communication that argues that the distribution of events in communicative contexts should maintain mutual predictability between language users, present evidence that the distributions of words in the empirical contexts in which they are learned and used are geometric, and thus support this. Here, we extend this analysis to a corpus of conversational English, showing that the distribution of grammatical regularities and the sub-distributions of tokens discriminated by them are also geometric. Further analyses reveal a range of structural differences in the distribution of types in parts of speech categories that further support the suggestion that linguistic distributions (and codes) are subcategorized by context at multiple levels of abstraction. Finally, a series of analyses of the variation in spoken language reveals that quantifiable differences in the structure of lexical subcategories appears in turn to systematically shape sublexical variation in speech signal.

A Survey of Phonological Mid Vowel Intuitions in Central Catalan

Catalan, like other Romance languages, has two pairs of phonemic mid vowels (/be/ "well" vs. /bɛ/ "lamb"; /os/ "bear" vs. /ɔs/ "bone"). However, these contrasts do not function like others in the language: they are partially phonologically conditioned, and evidence shows that words may be pronounced with different mid vowels by speakers of the same variety or even by the same speaker. Spanish may influence this instability, as first-language Spanish Catalan-Spanish bilinguals struggle to perceive and produce the contrast. This paper investigates the mid vowel contrasts in an Internet survey of vowel height judgments in 220 words by 146 Central Catalan-speaking individuals who also self-reported their language history. Results confirm that certain phonological contexts condition mid vowel height, typically favoring low mid judgments; where phonological conditioning occurs, speakers judge quality with increased consistency and confidence. Many words lacking phonological conditioning environments, however, are variable across speakers. Bilingualism levels and age have an effect: among Catalan-dominant participants, choice of mid vowel is affected by age, while participants with the highest Catalan dominance have greatest confidence in their intuitions. Variably-judged words are also phonetically variable, indicating a word-specific association between strength of phonological representation and realization.

Spectral moments vs discrete cosine transformation coefficients: Evaluation of acoustic measures distinguishing two merging German fricatives

The results of the quantification of the acoustic differences between German /ç/ and /ʃ/ in three speaker groups with varying contrast realizations are presented. Data for two speaker groups were collected in Berlin and Kiel, where the contrast is still realized. Data for a third group were collected in Berlin from speakers of Hood German-a youth-style multiethnolect spoken by adolescents in multilingual and multicultural neighborhoods of Berlin-where the contrast has weakened or is even lost. A forced choice perception test showed that listeners reliably differentiate these two fricatives in minimal pairs produced by the speakers from Berlin and Kiel, but fail to do so for the productions of the Hood German speakers. The acoustic analysis reveals that spectrally, the fricatives are very similar in all varieties. The spectral moments (Center of Gravity, standard deviation, kurtosis, skewness) fail to reveal the differences between the fricatives that are apparent from visual inspection of the spectra and the perceived auditory differences. Analyses of the discrete cosine transformation coefficients, however, better quantify these differences. This study suggests that minute differences between fricatives that vary between speaker groups may be captured more reliably with discrete cosine transformations compared to spectral moments.

K-SPAN: A lexical database of Korean surface phonetic forms and phonological neighborhood density statistics

This article presents K-SPAN (Korean Surface Phonetics and Neighborhoods), a database of surface phonetic forms and several measures of phonological neighborhood density for 63,836 Korean words. Currently publicly available Korean corpora are limited by the fact that they only provide orthographic representations in Hangeul, which is problematic since phonetic forms in Korean cannot be reliably predicted from orthographic forms. We describe the method used to derive the surface phonetic forms from a publicly available orthographic corpus of Korean, and report on several statistics calculated using this database; namely, segment unigram frequencies, which are compared to previously reported results, along with segment-based and syllable-based neighborhood density statistics for three types of representation: an "orthographic" form, which is a quasi-phonological representation, a "conservative" form, which maintains all known contrasts, and a "modern" form, which represents the pronunciation of contemporary Seoul Korean. These representations are rendered in an ASCII-encoded scheme, which allows users to query the corpus without having to read Korean orthography, and permits the calculation of a wide range of phonological measures.

Introduction to the special issue: parsimony and redundancy in models of language

One of the most fundamental goals in linguistic theory is to understand the nature of linguistic knowledge, that is, the representations and mechanisms that figure in a cognitively plausible model of human language-processing. The past 50 years have witnessed the development and refinement of various theories about what kind of 'stuff' human knowledge of language consists of, and technological advances now permit the development of increasingly sophisticated computational models implementing key assumptions of different theories from both rationalist and empiricist perspectives. The present special issue does not aim to present or discuss the arguments for and against the two epistemological stances or discuss evidence that supports either of them (cf. Bod, Hay, & Jannedy, 2003; Christiansen & Chater, 2008; Hauser, Chomsky, & Fitch, 2002; Oaksford & Chater, 2007; O'Donnell, Hauser, & Fitch, 2005). Rather, the research presented in this issue, which we label usage-based here, conceives of linguistic knowledge as being induced from experience. According to the strongest of such accounts, the acquisition and processing of language can be explained with reference to general cognitive mechanisms alone (rather than with reference to innate language-specific mechanisms). Defined in these terms, usage-based approaches encompass approaches referred to as experience-based, performance-based and/or emergentist approaches (Amrnon & Snider, 2010; Bannard, Lieven, & Tomasello, 2009; Bannard & Matthews, 2008; Chater & Manning, 2006; Clark & Lappin, 2010; Gerken, Wilson, & Lewis, 2005; Gomez, 2002;