Turkish-speaking dyzygotic twins (n = 21) and singletons (n = 23) were tested through a standard articulation test to observe whether their consonant articulations were related to their vocabulary sizes, recorded through CDI forms, at age 3;0. Twins were observed to lag behind their singleton peers and performed below the norm level in their…

Purpose: This meta-analysis study aimed to determine the optimal level of talker variability in training to maximize second-language speech learning. Method: We conducted a systematic search for studies comparing different levels of talker variability in nonnative speech training, published through July 2024. Two independent reviewers screened…

There is a long-standing debate in the literature about the benefits that acoustic components of Infant Directed Speech (IDS) might have for infants' language acquisition. One of the highly contested features is vowel space expansion, which refers to the enlargement of the acoustic space between the corner vowels /i, u, a/ in IDS compared to Adult…

Purpose: This study aims at investigating the phonological development of the six guttural consonants of Jordanian Arabic, /[chi]/, /[voiced uvular fricative]/, /[voiceless pharyngeal fricative]/, /[voiced pharyngeal fricative]/, /[glottal stop]/, and /h/. Method: An articulation test is designed to involve two tasks: picture naming and…

Purpose: Rhythm is one procedural mechanism that underlies language and motor skill acquisition and has been implicated in children with childhood apraxia of speech (CAS). The purpose of this study is to investigate manual rhythmic sequencing skills in children with a history of or current CAS (hx/CAS) compared to children with typical development…

The use of discourse markers, like that of any other linguistic element, is dependent on contextual factors that interact at the specific moment of an enunciation. The utterers, with the need to adjust their language product to their communicative intentions, perform an analysis of the contextual, material, and relational factors involved,…

Speech-to-text applications have great potential for helping students with English language comprehension and pronunciation practice. This study explores the functionality of five speech-to-text (STT) applications (Google Docs voice typing tool, Apple Dictation, Windows 10 Dictation, Dictation.io [a website service], and "Transcribe" [an…

This article investigates the production of the emphatic consonants /?, ?, ?/ by typically developing Jordanian children. Sixty typically developing monolingual Ammani Arabic-speaking children (30 boys and 30 girls) with ages ranging from 2 to 7;11 years were recruited in a production experiment. In the experiment, they were asked to produce 18…

We inquired whether introducing variability into a word-learning task would facilitate, inhibit, or have a neutral effect on adults' speech production and language learning. Twenty young adults from the U.S. Midwest with typical development participated. They repeated four novel words 10 times sequentially (blocked practice) and another four novel…

Recent work has shown significant sublexical effects of long-term memory in nonword repetition (NWR) using a dichotomous consonant age of acquisition (CAoA) variable (Moore, 2018; Moore, Fiez, and Tompkins, 2017). Performance consistently decreased when stimuli comprised consonants acquired later versus earlier in speech development. To address…

Covert contrast is the statistically reliable distinction between target language phonemes produced in the process of language acquisition that is nevertheless not perceived by a native speaker of that language. This paper examines the acquisition of contrasts in four Najdi Arabic fricatives, /s/, /[voiceless palato-alveolar fricative]/,…

The acoustic properties of infant-directed speech (IDS) have been widely studied, but whether and how young learners' language development benefits from individual properties remains to be confirmed. This study investigated whether toddlers' word processing was affected by tone hyperarticulation in the IDS of a tone language. Nineteen- and…

This study explored the initial stages of adult second language (L2) learning with a special focus on the acquisition of the target language sound system. The aim was to analyze the longitudinal development of Spanish stop voicing contrasts in an immersion learning context. Native English-speaking late learners of Spanish provided production data…

Purpose: This scoping review considers the acoustic features of a clear speech register directed to nonnative listeners known as foreigner-directed speech (FDS). We identify vowel hyperarticulation and low speech rate as the most representative acoustic features of FDS; other features, including wide pitch range and high intensity, are still under…

Anticipatory coarticulation is an indispensable feature of speech dynamics contributing to spoken language fluency. Research has shown that children speak with greater degrees of vowel anticipatory coarticulation than adults -- that is, greater vocalic influence on previous segments. The present study examined how developmental differences in…