Current theories of Autism Spectrum Disorder (ASD) suggest atypical use of context in ASD, but little is known about how these atypicalities influence speech perception. We examined the influence of contextual information (lexical, spectral, and temporal) on phoneme categorization of people with ASD and in typically developed (TD) people. Across…

Purpose: The /[voiced alveolar approximant]/ productions of young children acquiring American English are highly variable and often inaccurate, with [w] as the most common substitution error. One acoustic indicator of the goodness of children's /[voiced alveolar approximant]/ productions is the difference between the frequency of the second…

Purpose: The purpose of this study was to explore the relationship between speech perception, speech production, and vocabulary abilities in children with and without speech sound disorders (SSDs), analyzing the data both by group and continuously. Method: Sixty-one Australian English--speaking children aged 48-69 months participated in this…

Purpose: Vowels and consonants play different roles in language acquisition and speech recognition, yet standard clinical tests do not assess vowel and consonant perception separately. As a result, opportunities for targeted intervention may be lost. This study evaluated closed-set word recognition tests designed to rely predominantly on either…

Purpose: Envelope following responses (EFRs) could be useful for objectively evaluating audibility of speech in children who are unable to participate in routine clinical tests. However, relative to adults, the characteristics of EFRs elicited by frequency-specific speech and their utility in predicting audibility in children are unknown. Method:…

Background: Speech and language are interconnected systems, and language disorder often co-occurs with childhood apraxia of speech (CAS) and non-CAS speech sound disorders (SSDs). Potential trade-off effects between speech and language in connected speech in children without overt language disorder have been less explored. Method: Story retell…

Purpose: Phoneme categorization (PC) for voice onset time and second formant transition was studied in adult cochlear implant (CI) users with early-onset deafness and hearing controls. Method: Identification and discrimination tasks were administered to 30 participants implanted before 4 years of age, 21 participants implanted after 7 years of…

Infants born after fetal growth restriction (FGR)--an obstetric condition defined as the failure to achieve the genetic growth potential--are prone to neurodevelopmental delays, with language being one of the major affected areas. Yet, while verbal comprehension and expressive language impairments have been observed in FGR infants, children and…

Speech is highly variable and systematic, governed by the internal linguistic system and socio-indexical factors. The systematic relationship of socio-indexical factors and variable phonetic forms, referred to here as "socio-indexical structure," has been the cornerstone of sociophonetic research over the last several decades. Research…

When readers are asked to detect a target letter while reading for comprehension, they miss it more frequently when it is embedded in a frequent function word than in a less frequent content word. This missing-letter effect has been used to investigate the cognitive processes involved in reading. A similar effect, called the missing-phoneme effect…

The role of the right hemisphere in phonetic processing is thought to be relatively minimal, at least in comparison to the role of the left hemisphere. However, the right hemisphere is known to play a critical role in vocal identity processing, a fact that is striking given that the acoustic-phonetic details of the speech signal can differ…

The Perceptual Assimilation Model (PAM) (Best, 1995) claims listeners directly perceive articulatory gestures of the vocal tract rather than acoustic/auditory signals. Accordingly, the articulatory similarities and discrepancies between native and non-native sounds determine the perceptual assimilation patterns of non-native sounds. This study…

This study investigates how Korean students produce and perceive single and double consonant letters in English words. To this end, twenty-eight Korean learners of English participated in the production and perception tests of English consonants /p, b, s, d, k, g/ with single and double letters. The participants were first asked to produce English…

Dialects vary in their allophonic patterns, which can affect listeners' phonological and lexical representations. I explore how different exposure to dialect-specific allophonic patterns for two vowels in American English, /ae ai/, affects listeners' lexical processing behaviors across three perception tasks: perceptual similarity, priming, and…

Purpose: Evidence increasingly indicates that people with developmental stuttering have auditory perception deficits. Our previous research has indicated similar but slower performance in categorical perception of the speech sounds under the quiet condition in children who stutter and adults who stutter (AWS) compared with their typically fluent…