Abby Kaplan

High functional load inhibits phonological contrast loss: a corpus study.

For nearly a century, linguists have suggested that diachronic merger is less likely between phonemes with a high functional load--that is, phonemes that distinguish many words in the language in question. However, limitations in data and computational power have made assessing this hypothesis difficult. Here we present the first larger-scale study of the functional load hypothesis, using data from sound changes in a diverse set of languages. Our results support the functional load hypothesis: phoneme pairs undergoing merger distinguish significantly fewer minimal pairs in the lexicon than unmerged phoneme pairs. Furthermore, we show that higher phoneme probability is positively correlated with merger, but that this effect is stronger for phonemes that distinguish no minimal pairs. Finally, within our dataset we find that minimal pair count and phoneme probability better predict merger than change in system entropy at the lexical or phoneme level.

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

All languages use individually meaningless, contrastive categories in combination to create distinct words. Despite their central role in communication, these “phoneme” contrasts can be lost over the course of language change. The century-old functional load hypothesis proposes that loss of a phoneme contrast will be inhibited in relation to the work that it does in distinguishing words. In a previous work we showed for the first time that a simple measure of functional load does significantly predict patterns of contrast loss within a diverse set of languages: the more minimal word pairs that a phoneme contrast distinguishes, the less likely those phonemes are to have merged over the course of language change. Here, we examine several lexical properties that are predicted to influence the uncertainty between word pairs in usage. We present evidence that (a) the lemma rather than surface-form count of minimal pairs is more predictive of merger; (b) the count of minimal lemma pairs that share a syntactic category is a stronger predictor of merger than the count of those with divergent syntactic categories, and (c) that the count of minimal lemma pairs with members of similar frequency is a stronger predictor of merger than that of those with more divergent frequencies. These findings support the broad hypothesis that properties of individual utterances influence long-term language change, and are consistent with findings suggesting that phonetic cues are modulated in response to lexical uncertainty within utterances.

Perceptual Pressures on Lenition.

The phonological processes known as ‘lenition’ have traditionally been explained as articulatory effort reduction. However, such a motivation for lenition has never been directly demonstrated; in addition, there are reasons to doubt the articulatory explanation.This paper focuses on a particular type of lenition (intervocalic spirantization of voiced stops) and presents two experiments that investigate what role, if any, perceptual considerations might play in lenition. Experiment 1 shows that spirantization of intervocalic voiced stops is a less perceptually salient change than devoicing of intervocalic voiced stops (an unattested process). Using the line of reasoning of Steriade’s P-map hypothesis, perceptual facts offer an alternative to the articulatory account: lenition of intervocalic voiced stops yields spirants rather than voiceless stops because the latter change is perceptually highly salient. The results of Experiment 2 show that the perceptual facts differ by place of articulation, such that the difference between stops and spirants is greater for labials than for dorsals. These results do not match the attested typology; if anything, languages are more likely to spirantize labials than they are to spirantize dorsals. Thus, perceptual facts have the potential to explain some, but not all, of the typology of lenition.

How much homophony is normal? 1

This paper argues that neutralizing phonological alternations are sensitive to how much homophony they create among distinct lexical items: neutralizing rules create fewer homophones than expected. Building on a case study of Korean by Silverman (2010), I compare the neutralizing rules of Korean to a large number of hypothetical alternatives generated by Monte Carlo simulations. The simulations reveal that the actual rules of Korean frequently create far fewer homophones than similar (but unattested) rules, even when the rules that are compared are controlled for the number of phonemic contrasts they eliminate. These results suggest that phonological patterns are sensitive not only to high-level contrasts among phonemes but also to contrasts among individual lexical items. The effect is most pronounced when homophones are not weighted by frequency, a result that adds to evidence in the literature that the relevant measure of lexical frequency for many lexicon-sensitive phonological patterns is type frequency, not token frequency.

Categorical and gradient homophony avoidance: Evidence from Japanese

Abstract Many languages have been claimed to have phonological patterns that are sensitive to the need to avoid homophony – for example, a rule that is blocked if it would create a surface form that is identical to another word in the language. Such patterns always involve comparisons between words in the same morphological paradigm (e.g., singular and plural forms with the same stem). The lone exception to this generalization is Ichimura (2006), who argues that a nasal contraction pattern in Japanese is blocked by potential homophony between verbs with different stems. We present experimental evidence that homophony avoidance is not part of the correct synchronic description of the environment in which this pattern applies; rather, nasal contraction does not productively delete stem-final vowels. However, homophony avoidance does appear to affect the probability with which contraction applies. We conclude that homophony avoidance affects phonological behavior, but that absolute homophony-related blocking is restricted to morphological paradigms.

A Highly Improbable Data Point

Several recent papers (Silverman 2010; Kaplan 2011; Wedel et al. 2013a,b) have presented evidence in favor of the longstanding functional load hypothesis (Martinet 1952; Hockett 1967), arguing that phoneme pairs that distinguish many words are unlikely to undergo merger, and that this phenomenon can be detected in sufficiently large datasets. In contrast with some other approaches (e.g., King 1967), these recent studies assume that functional load operates as a statistical tendency: homophony avoidance is one factor among many that influences the course of sound change, and does not by itself predict whether a given pair of sounds will merge or not. Geoffrey Sampson observes that many of the sound changes that have occurred in the history of Chinese involve merger, and that the result of these mergers is homophony on a massive scale. He notes that homophone creation of this magnitude is unexpected if there is indeed a tendency for pairs of sounds with high functional load to avoid merger. To get a sense of just how unusual the Chinese case is, consider the following examples. Table 1 lists several phoneme pairs from the dataset used in Wedel et al. (2013b). For each pair, the table gives the raw number of minimal pairs distinguished by those phonemes (in a particular position, if relevant) and the probability of merger between those phonemes as predicted by the logistic regression model of Wedel et al. (2013b). Note that we do not claim that these estimates represent, in any concrete sense, the actual probability that a particular pair of sounds