Speech Sound Disorders

Speech sound disorders (SSD) are the most common communication disorder in the pediatric population, impacting approximately 10 to 15 percent of children between 4 and 5 years old (Gierut, 1998 & McLeod & Harrison, 2009). SSDs result in speech intelligibility, occurring from difficulties in motor production of speech, phonological awareness of vowels and consonants, syllable discrimination, and the ability to understand rhythm, stress, and intonation of words (Bowen, 2015). Children diagnosed with SSD contribute to more than 70% of a speech-language pathologist’s (SLP) caseload (Waring & Knight, 2013). However, SSDs vary by degree of severity and deficits in each child, resulting in different targets during treatment.

Research compiled three

factors to target during treatment of a SSD: sound development, stimulability for sounds, and treatment word selection. It was first recommended that SLPs target earlier developing sounds, sounds that the child is stimulable for, and use real-words in order to promote generalization and overall phonological improvement (Khan & Lewis, 1990; Rvachew & Nowak, 2001). However, targeting later developing sounds, sounds that the child is not stimulable for, and the use of later developing, or non-words in therapy sessions is becoming more popular when implementing the overall factors into treatment (Gierut, 1998, 2007). This paper will analyze the three factors to determine the best target for treating SSD in order to elicit effective phonological growth in a child’s speech production.
Analysis of Factors
In order to best determine an effective treatment plan for a child with SSD, several factors, as well as the proper target to implement the factors must be selected.
The first factor that contributes to SSD treatment is sound development. However, there is controversial research arguing if targeting earlier or later developing sounds is best. A typically developing child acquires sounds based on how easy the sounds are produced by the articulators. Thus, several professionals conclude that children with SSD should follow the same acquisition pattern, because earlier developing sounds are easier to produce and learn (Khan & Lewis, 1990). Typically developing children should acquire the phonemes /p,b,t,d,k,g,m,n,f,w, ŋ/ by age 3, making them early developing sounds (Bowen, 2015; McLeod, 2009). Later developing phonemes, /r,z,s,l,θ,ð,ʃ, dʒ/ should all appear by age 5 or later, classifying them as later developing (Bowen, 2015; McLeod, 2009).
Several research studies have been conducted to better support the use of early-developing sounds to improve the sounds system in a child with SSD.

One study conducted by found that auditory bombardment techniques targeting familiar sounds in the child’s repertoire using minimal pair or cycles therapy techniques led to overall improvement in sound production (Khan & Lewis, 1990). Comparatively, another study indicated that children who received therapy targeting phonemes familiar to the child, (but were not yet mastered) showed significant gains in generalization of phonological knowledge than children who received therapy for unfamiliar, more complex sounds (Rvachew & Nowak, 2001). Finally, a study was conducted comparing research, which supported use of early developing sounds to a study supporting use of later developing sound targets. Conclusions indicated that children who targeted familiar phonemes made more spontaneous gains in in later-developing sounds (Gierut, 2007; Rvachew & Nowak, 2001, 2003). This study also determined that children targeting complex sounds made less gain in phonological knowledge, supporting the target of using earlier developing, familiar sounds, to improve acquisition of new sounds in treatment (Gierut,

2007).
However, there is evidence supporting the use of later-developing sounds in phonological treatment methods.

Researchers conclude that later developing sound targets may be difficult to produce for the child, but, with implemented therapy techniques, mastering of later developing sounds make larger gains in the entire phonological system (Gierut, 2007). Gierut’s study indicated that integrating complex targets into therapy sessions increased generalization and carry over of complex and simple phonemes into the child’s sound system (Gierut, 2007). These results were validated in a comparison study, indicating that assignment of later-developing sounds increases generalization across speech production (Morrissette & Gierut, 2003). Additionally, a study involving one child with SSD supported the use of complex, later developing sounds. Although the child did not improve his entire sound system, he improved his use of complex sounds and acquired earlier developing sounds that were not consistently used in his sound system (Glaspey & Macleod,

2010).
There is valid research arguing that each target for sounds development is successful in treating sound differences in SSD. However, using later-developing sounds is the most beneficial. Targeting later developing sounds gives the opportunity to generalize concepts and master earlier developing sounds without specifically targeting them (Gierut, 2007). Also, when time constraints are involved, targeting later developing sounds will yield overall success significantly faster than targeting earlier, than later developing sounds (Glaspey & Macleod, 2009). Sound target selection is directly influenced by the second factor of stimulability and it’s specific targets as well (Brumbaugh & Smit, 2013).