Introduction

The following exercise is a case study of a 7-year-old boy (‘Jarrod’) with developmental phonological disorder who was studied by Holm and Crosbie (Reference Holm and Crosbie2006). Jarrod is a monolingual, Australian English-speaking child. His phonological impairment is severe in nature. The case study is presented in five sections: primer on developmental phonological disorder; client background; medical, developmental and educational history; speech, language and cognitive evaluation; and focus on articulation and phonology.

Primer on developmental phonological disorder

Developmental phonological disorder (DPD) is a type of speech sound disorder. The American Speech-Language-Hearing Association (2015) states that:

The phonological impairment in DPD can compromise speaker intelligibility to varying degrees, with some children so severely affected that they are completely unintelligible to all but the most familiar listeners. DPD exists in the absence of a known aetiology. So while children with hearing loss, craniofacial anomalies (e.g. cleft lip and palate), neurological damage and intellectual disability in the presence of syndromes (e.g. Down's syndrome) can also have problems with the production of speech sounds, their speech sound disorder has an identifiable organic aetiology which differs from the functional or unknown aetiology of DPD.

The prevalence of DPD and speech sound disorders varies according to different investigations. In a study of 1,494 4-year-old Australian children, Eadie et al. (Reference Eadie, Morgan, Ukoumunne, Ttofari, Wake and Reilly2015) reported that the prevalence of idiopathic speech sound disorder was 3.4%. McKinnon et al. (Reference McKinnon, McLeod and Reilly2007) obtained a lower prevalence of speech sound disorder, 1.06%, in a study of 10,425 primary school students in Australia. In the United States, Shriberg et al. (Reference Shriberg, Tomblin and McSweeny1999) estimated the prevalence of speech delay (a type of speech sound disorder) to be 3.8% in 1,328 monolingual English-speaking 6-year-old children. A consistent finding across all studies is that many more boys than girls develop speech sound disorders. Shriberg et al. reported that speech delay was approximately 1.5 times more prevalent in the boys (4.5%) than in the girls (3.1%) in their study. Children with speech sound disorders often have comorbid conditions such as reading disability and language impairment. In their sample of 1,494 Australian children, Eadie et al. (Reference Eadie, Morgan, Ukoumunne, Ttofari, Wake and Reilly2015) reported that comorbidity with speech sound disorder was 40.8% for language disorder and 20.8% for poor pre-literacy skills. Sices et al. (Reference Sices, Taylor, Freebairn, Hansen and Lewis2007) reported that 53% of 125 children aged 3 to 6 years with moderate to severe speech sound disorder had comorbid language impairment.

Speech errors in children with speech sound disorders have been extensively investigated. McLeod et al. (Reference McLeod, Harrison, McAllister and McCormack2013) analysed the speech features of 143 children aged 4 to 5 years who were assessed following parent/teacher concern regarding their speech skills. A standard score below the normal range for the percentage of consonants correct on the Diagnostic Evaluation of Articulation and Phonology (Dodd et al., Reference Dodd, Hua, Crosbie, Holm and Ozanne2002) was obtained by 86.7% of children. Consonants produced incorrectly were consistent with the late eight phonemes. Common phonological patterns in these children were fricative simplification (82.5%), cluster simplification (49.0%) and cluster reduction (19.6%), gliding (41.3%) and palatal fronting (15.4%). Interdental lisps on /s/ and /z/ were produced by 39.9% of children, while dentalisation of other sibilants and lateral lisps were identified in 17.5% and 13.3% of children, respectively.

Client background

Jarrod was born in New Zealand but moved to Australia at 2 years of age. He lives with his mother and 10-year-old sister. He sees his father regularly. His mother has a partner, with whom Jarrod does not have a close relationship. Jarrod has regular contact with extended family members. English is the only language spoken at home. Jarrod's mother works part-time as a bookkeeper, and his father is a full-time builder. Jarrod's father had a speech disorder as a child, and attended speech therapy. He still produces some speech errors. His maternal grandfather has a history of dyslexia. Jarrod's sister has bilateral integration problems, in that she struggles to integrate information from the left and right side of the brain.

Jarrod is described by his mother as being a happy, healthy boy who has a good sense of humour. His mother reports him as enjoying a number of activities – playing with his friends and on the computer, watching television and movies. She believes his speech problems have held him back but that he has still been able to forge friendships. For example, he plays with other children in the neighbourhood, and attends other children's parties. Jarrod's teacher also acknowledges that he has friends and that he participates happily in classroom activities. However, she says that he does not have particularly good social interactions. This is reflected in a report written by his teacher about an Intensive Language Class that Jarrod attends. Jarrod was described as having ‘poor social skills as a result of poor communication skills’. The report also noted that Jarrod was aware of his communication problems and was sensitive about them. Jarrod has been teased by other children about his speech difficulties.

Within a known conversational context, Jarrod's mother and teacher could usually understand him. However, without context he was difficult to understand, and unfamiliar listeners, his mother reported, did not understand him. Jarrod did not get frustrated when he was not understood. He readily repeated himself or reformulated his message and would use gesture and drawings to help understanding. Despite his problems, he was not inhibited about communicating. For example, he was willing to address the school at assembly, even though he was not understood, and he answered questions in class and participated in group discussions.

Medical, developmental and educational history

Jarrod's mother had an uneventful pregnancy and labour. Jarrod was born full-term and had an average birth weight. With the exception of ‘clicky’ hips, no other medical condition was identified at birth. Jarrod was breastfed for 6 months, and had no feeding difficulties. His gross motor development milestones were normally achieved. However, an occupational therapy assessment revealed some fine motor difficulties, although his writing abilities were good for his age. At 15 months, Jarrod was diagnosed with asthma, for which he has been using a Ventolin and Flexotide nebuliser. He has been hospitalised twice for the treatment of asthma. Jarrod has also been diagnosed with attention deficit hyperactivity disorder (ADHD) and has been taking Ritalin for approximately two months. Jarrod's mother and teacher report an improvement in his attention with this medication. At 2 and 4 years of age, Jarrod had grommets inserted for the treatment of otitis media. At 4;1 years, his hearing was tested and was judged to be adequate for the development of speech and language. Jarrod's mother and teacher have not reported any ongoing hearing difficulties.

Jarrod attended preschool. During the year in which he turned five, he was enrolled in a Special Education Development Unit. He attended a mainstream class the following year. When he was assessed for this study, he was enrolled in an Intensive Language Class of children with identified communication problems. The teacher of this class prepared a report on Jarrod at the end of the school year. Her comments identified several areas in which Jarrod had improved: organisational skills; self-esteem; attention; and fine motor skills. Jarrod had also developed a good understanding of the role of phonics and could recognise phonic sounds in isolation. He displayed a fair understanding of mathematical processes and was reported to enjoy mathematical activities. However, he had significant difficulties with reading and displayed reversal problems in both letters and numbers. The teacher remarked that Jarrod had a good sense of humour, enjoyed coming to school and liked narrative activities (listening to stories and engaging in retell).

Speech, language and cognitive evaluation

Jarrod was extensively evaluated. A wide range of assessments was used: seven speech assessments; an oromotor assessment; three psycholinguistic assessment tasks; three phonemic awareness assessments; an assessment of activity and participation; and an assessment of non-verbal cognitive abilities. Several of these assessments and their results are described below.

Focus on articulation and phonology

Jarrod's single-word productions on the articulation subtest of the Diagnostic Evaluation of Articulation and Phonology (Dodd et al., Reference Dodd, Hua, Crosbie, Holm and Ozanne2002) underwent phonetic transcription. The phonemic targets are for the pronunciation of Australian English. Where symbols have superscript, it represents an impression that a sound or sound sequence is either epenthetic or a transition between sounds. Short extracts of Jarrod's connected speech are transcribed below the table.