Purpose: Apraxia of speech (AOS) is a motor speech disorder affecting articulatory planning and speech programming. When AOS is the sole manifestation of neurodegeneration, it is termed primary progressive apraxia of speech (PPAOS). Recent work has shown that there are distinct PPAOS subtypes: phonetic, prosodic, and those that do not clearly…

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…

Background: Previous research has found that high-frequency energy of speech signals decreased while wearing face masks. However, no study has examined the specific spectral characteristics of fricative consonants and vowels and the perception of clarity of speech in mask wearing. Aims: To investigate acoustic-phonetic characteristics of fricative…

Purpose: The human voice changes with the progression of neurological disease and the onset of diseases that affect articulators, often decreasing the effectiveness of communication. These changes can be objectively measured using signal processing techniques that extract acoustic features. When measuring acoustic features, there are often several…

Purpose: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that affects bulbar functions including speech and voice. Voice onset time (VOT) was examined in speakers with ALS in early and late stages to explore the coordination of the articulatory and phonatory systems during speech production. Method: VOT was measured in nonword…

Purpose: This study investigated articulatory patterns for American English /[Voiced alveolar approximant]/ in children with and without a history of residual speech sound disorder (RSSD). It was hypothesized that children without RSSD would favor bunched tongue shapes, similar to American adults reported in previous literature. Based on clinical…

Across languages, certain syllables are systematically preferred to others (e.g., "plaf > ptaf"). Here, we examine whether these preferences arise from motor simulation. In the simulation account, ill-formed syllables (e.g., "ptaf") are disliked because their motor plans are harder to simulate. Four experiments compared…

Background: Publicly available speech corpora facilitate reproducible research by providing open-access data for participants who have consented/assented to data sharing among different research teams. Such corpora can also support clinical education, including perceptual training and training in the use of speech analysis tools. Purpose: In this…

We examined genre-specific reading strategies for literary texts and hypothesized that text categorization (literary prose vs. poetry) modulates both how readers gather information from a text (eye movements) and how they realize its phonetic surface form (speech production). We recorded eye movements and speech while college students (N = 32)…

Infant-directed speech (IDS) is phonetically distinct from adult-directed speech (ADS): It is typically considered to have special prosody--like higher pitch and slower speaking rates--as well as unique speech sound properties, for example, more breathy, hyperarticulated, and/or variable consonant and vowel articulation. These phonetic features…

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 whether audiovisual phonetic training with hand gestures encoding visible or nonvisible articulation features has a differential impact on learning second language sounds. Ninety-nine Catalan-Spanish bilingual students were trained to differentiate English /ae/ and /[lambda]/, which differ in the visible lip aperture and…

A prominent hypothesis holds that by speaking to infants in infant-directed speech (IDS) as opposed to adult-directed speech (ADS), parents help them learn phonetic categories. Specifically, two characteristics of IDS have been claimed to facilitate learning: "hyperarticulation," which makes the categories more "separable," and…

Purpose: We compare teens' and adults' imitation of sentences with shortened and lengthened voice onset time (VOT), in order to test whether purported age-based advantages in phonetic acquisition may be due to differences in imitative ability. Method: Teens (M[subscript age] = 13, n = 39) and adults (n = 31) completed an explicit imitation and…