Kang, Yein and Jonny Jungyun Kim. 2026. Does AI reflect sound change? A comparison of human and TTS production of Korean stops. Linguistic Research 43(1): 105-140. This study presents an acoustic analysis of speech generated by 60 commercial text-to-speech (TTS) voices to examine whether socially indexed phonetic variation is reflected in artificial speech systems. Focusing on cross-generational variation in phrase-initial Korean stops, we investigated the extent to which voices labeled as "younger" across three TTS platforms approximate the ongoing merger in voice onset time (VOT) between aspirated and lenis stops, as well as a compensatory cue-shift toward fundamental frequency (F0). Younger TTS voices generally showed reduced reliance on VOT cues: for example, IP-initial aspirated and lenis stops differed by 12ms in younger TTS voices, compared to 21ms in older TTS voices. However, the magnitude of this merger in younger TTS voices differed substantially from that observed in younger human speakers, who exhibited an almost complete VOT merger (e.g., a 1ms difference, IP-initially). In contrast, F0 patterns in TTS speech broadly aligned with human speech. The results suggest a potential link between socially indexed phonetic realization and naturalness fidelity in AI-generated speech. We further outline future directions for examining AI speech from a sociophonetic perspective, focusing on fundamental differences between human and machine learning mechanisms. (Pusan National University)
Dita, Shirley N. and Jong-Bok Kim. 2026. Answering polar questions in Tagalog: A discourse-based analysis. Linguistic Research 43(1): 31-59. This paper explores strategies for forming and answering polar questions in Tagalog. While K & ouml;nig and Siemund (2007) identify six strategies for generating polar questions cross-linguistically, only three are evident in Tagalog: special intonation patterns, interrogative particles, and special tags. More significantly, this study reveals that Tagalog exhibits flexibility in its answering system, employing all three response strategies described by Sadock and Zwicky (1985)- yes/no (polarity), agree/disagree (truth), and echo systems. Using authentic examples from the web-based corpus tlTenTen19, we demonstrate that Tagalog response particles oo and hindi function as anaphoric elements referring to salient propositions in discourse, challenging simple binary typologies and supporting recent discourse-based accounts of response particles (Kim 2024). This analysis contributes to our understanding of Philippine languages and cross-linguistic variation in answering systems. (De La Salle University & centerdot;Kyung Hee University)
In sociophonetics and laboratory phonology, researchers often invoke "listener sensitivity," meaning that some individuals or groups notice and differentiate fine-grained phonetic variation more than others, yet this construct is rarely operationalized as a single gradient measure. We introduce a simple, generalizable metric, the sensitivity score, defined as the sum of absolute differences between a participant's mean ratings across all unordered pairs of variants. We demonstrate the metric using a perception experiment on Korean aegyo, a cuteness-indexed register with segmental alternations including nasal insertion, /j/-insertion, and vowel rounding. Forty-three native Korean listeners rated 90 spoken stimuli each (15 variants & times; 6 predicates; 3870 ratings total), produced by two talkers, on a 1-7 aegyofulness scale. We analyze the token-level ratings with a linear mixed-effects model comparable to Jang (2021) and analyze sensitivity scores computed within each predicate (six scores per participant; 258 scores total) with a second mixed-effects model. The token-level model replicates broad social patterning in aegyo evaluations, while the sensitivity score provides a transparent participant-and item-level summary of overall differentiation. Women show higher sensitivity than men, and age shows a trend, such that younger listeners show higher sensitivity than older listeners. Aggregating ratings into sensitivity scores reduces the number of observations relative to token-level modeling, so we treat the metric as complementary to traditional statistical methods. Beyond aegyo, the approach is portable to other sociophonetic, prosodic, and sound-symbolic domains.
This study demonstrates that a muscle-based approach provides an explanatory account of the affrication and palatalization of Japanese /t/ that are difficult to explain using conventional phonological approaches. The central asymmetry is that /t/ becomes [tc] with a posterior place before front high /i/, whereas it becomes [ts] without change in place of articulation before non-front high /w/. The results of the simulations using the 3D tongue model of ArtiSynth show that the shape of the tongue for the letter /t/ varies depending on the coarticulated tautosyllabic vowels. This is because the activated muscle bundle of the tongue differs based on the vowels. In the context of /i/, a muscle activation lowering the tip of the tongue is essential to keep the tip of the tongue from going out of the mouth. The palatalization of /t/ is characterized by a lowered tongue tip and an elevated tongue body. In the coarticulation of tautosyllabic /t/ and /w/, the activated tongue muscle raised the entire tongue without significantly lowering the tongue tip, causing affrication of /t/. The affrication and palatalization of Japanese /t/ are formally captured in an Optimality-Theoretic (OT) analysis as assimilations of constriction orientation (CO) between the tongue tip and body in tautosyllabic onset-vowel sequences, grounded in a muscle-based account and gestural representations. The proposed OT grammar that uses AGREE(CO) and IDENT(CO) can derive the Japanese /t/ alternation patterns. (Sungkyunkwan University)
Recent studies have documented the raising of the mid-back vowel [o] toward the high-back vowel [u] in Seoul Korean (SK), raising questions about whether this shift reflects a merger or a chain shift. This study investigates whether [o]-raising induces a reorganization of the vowel space involving adjacent vowels [u], [Lambda], and [w]. Analyzing vowel productions from 22 SK speakers (16 female, 6 male) across two speech styles (careful vs. conversational), we examined acoustic properties of three vowel pairs: [o]-[u], [w]-[u], and [Lambda]-[o]. Results show that [u] remains distinct from [o] and is produced in a significantly more fronted position, especially in conversational speech. Additionally, [u] was shifted closer to [w], and [Lambda] raised, suggesting a broader vowel chain shift. These findings provide acoustic evidence of an ongoing, systemic restructuring of the SK vowel system. (Chungbuk National University & centerdot; Korea Aerospace University & centerdot; University of Oregon)
