Speech Impairment in Down Syndrome: A Review

Abstract

Purpose This review summarizes research on disorders of speech production in Down Syndrome (DS) for the purposes of informing clinical services and guiding future research. Method Review of the literature was based on searches using Medline, Google Scholar, Psychinfo, and HighWire Press, as well as consideration of reference lists in retrieved documents (including online sources). Search terms emphasized functions related to voice, articulation, phonology, prosody, fluency and intelligibility. Conclusions The following conclusions pertain to four major areas of review: (a) Voice. Although a number of studies have been reported on vocal abnormalities in DS, major questions remain about the nature and frequency of the phonatory disorder. Results of perceptual and acoustic studies have been mixed, making it difficult to draw firm conclusions or even to identify sensitive measures for future study. (b) Speech sounds. Articulatory and phonological studies show that speech patterns in DS are a combination of delayed development and errors not seen in typical development. Delayed (i.e., developmental) and disordered (i.e., nondevelopmental) patterns are evident by the age of about 3 years, although DS-related abnormalities possibly appear earlier, even in infant babbling. (c) Fluency and prosody. Stuttering and/or cluttering occur in DS at rates of 10 to 45%, compared to about 1% in the general population. Research also points to significant disturbances in prosody. (d) Intelligibility. Studies consistently show marked limitations in this area but it is only recently that research goes beyond simple rating scales.

Características fonéticas e contrastes fonológicos em dados de fala de pessoas com down: perspectiva da geometria de traços

“…As conclusões gerais dos autores, a partir de pesquisas sobre percepção e articulação, são as de que existe um atraso global no desenvolvimento fonético/fonológico de pessoas com síndrome de Down. (Kent e Vorperian, 2013).…”

The Home Literacy Environment of Preschool-Age Children with Autism or Down Syndrome

“…Phonological, articulatory, motoric, and prosodic factors contribute to persistent difficulties with speech sound production and intelligibility that are almost universal [32-34]. Children with Down syndrome are slow to begin talking and to learn new words, with expressive vocabulary affected more than receptive, and syntax particularly compromised, resulting in shorter, simpler utterances with fewer different words and morphological markers [35, 36].…”

Normative Nasalance Scores for Brazilian Portuguese Using New Speech Stimuli

“…The Nasometer (Kay Elemetrics Corporation, Lincoln Park, N.J., USA) quantifies nasalance as the ratio of nasal acoustic energy to the sum of nasal plus oral acoustic energy, expressed as a percentage. Measures of nasalance have been used to document oral-nasal balance in numerous clinical populations, including cleft palate, neurogenic dysarthrias and hearing impairment [7,8,9,10,11,12,13]. …”