Speak properly, and in as few words as you can, but always plainly; for the end of speech is not ostentation, but to be understood.
William Penn (1644–1718)1
Relationships of speech to language and communication are so transparent in everyday communication that the remarkable ability for speech to convey linguistically encoded information and influence understanding can be easily overlooked. In the introductory quotation to this editorial, William Penn cautioned against becoming so enamored with the sounds of one's words that their communicative effectiveness gets lost or at least diminished in focus. On another level, however, it is appropriate for speech–language pathologists, reading specialists, psychologists, and general and special educators to take a closer look at the phenomenon of speech sound production and its development and disorders.
Studies of children with speech sound disorders (SSD) present opportunities to answer questions with theoretical and practical implications. Do all children who show difficulty with speech sound production share common characteristics, or might there be subgroups of children who demonstrate patterns of related abilities and disabilities that set them apart? What are the relationships of speech sound production proficiency in children to other important developmental abilities—from language and reading to fine motor skills and other oral motor skills? Issues related to questions such as these are addressed by the issue editor, Ann Tyler, and the authors who contributed to this topical issue on “Speech Sound Disorders in Children: Exploring Subgroups.”
As Penn warned, it is possible to overlook potentially important relationships if one becomes too focused on one dimension of a problem and loses sight of others. Speech–language pathologists and others who study speech production as a science or a clinical problem need an even higher power lens than the orators to whom Penn was directing his advice.
In recent decades the lenses used by scientists and clinicians have become increasingly wide-angled as well as higher powered. Following Catts' (1993) seminal article about relationships between isolated speech impairments, speech-and-language impairments, and reading disabilities, school practitioners may be more likely now to consider whether a child with SSD might have a comorbid language impairment and, hence, be at greater risk for reading difficulty. Catts' work highlighted the need for more information about potentially related subsystems (e.g., speech, language, and reading) as input to decisions about assessment, eligibility, and treatment for children with SSDs. If children with SSD can be classified into subgroups, children in each group may have substantively different needs.
As reported in this issue, the lenses available today to scientists and clinicians are being powered by new tools. They include enhanced research methods for studying genetics and familial patterns (as in the articles by Peter and Raskind and also by Lewis, Avrich, Freebairn, Taylor, Iyengar, and Stein). They also include new measurement techniques, such as computer-assisted analysis of children's general cognitive ability to learn patterns (as in the article by Dodd) and computer-assisted analysis of acoustic data representing variability of phonetic tokens for comparison with transcription data (as in the article by Preston and Koenig). In this issue, readers will also find an example of enhancing power by conducting an intervention study across continents. Clinical researchers Tyler (in the United States) and Gillon (in New Zealand), in association with colleagues, Macrae and Johnson, provide data that support the needs of children with speech-and-language difficulties to receive intervention that integrates explicit instruction about phonemes and letters, along with opportunity to practice integrating speech sounds and morphemes in words.
So what are the answers to the questions about whether different groups of children can be identified and the degree to which difficulty in one domain predicts associated difficulty in another? It is too simplistic to distill the collective results of this set of rich empirical studies into a few conclusions, but it is worthwhile to focus on a few take-home points. These studies (particularly Dodd) add to the literature that suggests that literacy learning risks are greater for children with SSDs that involve unusual patterns of production than for those whose speech is more simply delayed. The results (particularly Lewis et al.) also indicate that problems of phonemic awareness (and also reading difficulty) are associated more strongly with having language impairment along with SSD than with the severity of the SSD, whereas vocabulary difficulty is associated with both having comorbid language and reading problems and having a more severe form of SSD. Consistent with these findings, Tyler and colleagues report advantages for targeting language and literacy abilities (phonemic awareness, letter awareness, and morphosyntactic skill) along with speech sound production. Peter and Raskind provide evidence that SSDs traditionally considered purely “functional,” such as frontal lisping, actually can be attributed to familial patterns. It is also intriguing to find that variability in phoneme production and other oral motor skills may not be such a strong indicator of more severe or related problems as one might think, at least by the time children with SSD are of school age (as reported by Preston and Koenig).
As this summary suggests, this issue offers rich opportunities to think about speech sound production as a primary channel of communication and reflect on the ramifications of unclear speech in the developing child. I recommend the issue to readers with enthusiasm. Also be sure to visit the journal's Web site, www.topicsinlanguagedisorders.com, to try out the new “Quick Poll” feature related to this topic, while this issue of the journal is spotlighted.
—Nickola Wolf Nelson, PhD