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: Despite known motor and spoken language impairments in autism spectrum disorder (ASD), the motor skills underlying speech production and their relationship with language skills have rarely been directly investigated in this population. Method: Thirty-nine autistic children (14 minimally verbal [MV], 25 verbal [V]) and 11 non-autistic…

Previous research on infant-directed speech (IDS) and its role in infants' language development has largely focused on mothers, with fathers being investigated scarcely. Here we examine the acoustics of IDS as compared to adult-directed speech (ADS) in Norwegian mothers and fathers to 8-month-old infants, and whether these relate to direct…

The present study investigates the time course of acoustic cue integration in the processing of the Korean three-way laryngeal stop contrast by native Korean listeners and English second language (L2) learners of Korean. As such, this study seeks to understand how native listeners and L2 learners weight and integrate fine-grained acoustic…

During conversation, talkers may adapt their speech in a variety of ways. One form of speech adaptation is clear speech, in which a talker selectively hyperarticulates segments when faced with specific communication challenges. The present speech production experiment investigated how talkers adapt a common feature of American English dialects:…

Purpose: The purpose of this study was to examine the extent to which phonological competition and semantic priming influence lexical access in school-aged children with cochlear implants (CIs) and children with normal acoustic hearing. Method: Participants included children who were 5-10 years of age with either normal hearing (n = 41) or…

Purpose: It is generally accepted that adults use visual cues to improve speech intelligibility in noisy environments, but findings regarding visual speech benefit in children are mixed. We explored factors that contribute to audiovisual (AV) gain in young children's speech understanding. We examined whether there is an AV benefit to…

This work examines the link between low-level cortical acoustic processing and higher-level cortical phonemic processing. Specifically, using functional magnetic resonance imaging, it looks at 1) whether or not the vowels [alpha] and [i] are distinguishable in regions of interest defined by the first two resonant frequencies (formants) of those…

Consonants and vowels differ acoustically and articulatorily, but also functionally: Consonants are more relevant for lexical processing, and vowels for prosodic/syntactic processing. These functional biases could be powerful bootstrapping mechanisms for learning language, but their developmental origin remains unclear. The relative importance of…

We examined how toddlers process lexical ambiguity where different underlying forms are neutralized at the surface level. In a preferential-looking procedure, French-learning 30-month-olds were familiarized with either liaison-ambiguous phrases (i.e., sentences containing a determiner and a non-word, e.g., "ces /z/onches," "these…

This study examined intelligibility of twelve American English vowels produced by English, Chinese, and Korean native speakers in quiet and speech-shaped noise in which vowels were presented at six sensation levels from 0 dB to 10 dB. The slopes of vowel intelligibility functions and the processing time for listeners to identify vowels were…

Acoustic and perceptual studies investgate B2-level Polish learners' acquisition of second language (L2) English word-boundaries involving word-initial vowels. In production, participants were less likely to produce glottalization of phrase-medial initial vowels in L2 English than in first language (L1) Polish. Perception studies employing word…

This study investigated the role of inhibition in second language (L2) learners' phonological processing. Participants were Spanish learners of L2 English and American learners of L2 Spanish. We measured inhibition through a retrieval-induced inhibition task. Accuracy of phonological representations (perception and production) was assessed through…

Motivated by predictions of the theory of Input Processing, this study adds to previous research on second language (L2) Spanish pronunciation learning by investigating the impact of two distinct types of pronunciation assignments on first language (L1) English L2 Spanish students' improvement in pronunciation of the vowels /e, o/. Two sections of…

Speech production is inextricably linked to speech perception, yet they are usually investigated in isolation. In this study, we employed a verbal-repetition task to identify the neural substrates of speech processing with two ends active simultaneously using functional MRI. Subjects verbally repeated auditory stimuli containing an ambiguous vowel…