ACQ Vol 13 No1 2011

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22 ACQ Volume 13, Number 1 2011 ACQuiring knowledge in speech, language and hearing
encouraged to identify the target phoneme in the context of
one of the target words, to identify and label the sounds and
names for the target phoneme, as well as to practise
accurate production of the target phoneme in words. For the
PA activities that incorporated word-initial /s/ cluster speech
targets, participants were requested only to identify the /s/.
The developmental appropriateness of this task is supported
by the work of Stahl and Murray (1994) who report that
kindergarteners and first graders were able to identify the
initial phoneme in CCVC words with a mean accuracy of
72%.
Morphosyntax and speech intervention
The MS intervention program alternated between two
sessions targeting a morphological structure followed by two
sessions of speech intervention the week after. The three
morphological structures that were targeted during
intervention were: the regular third person singular form of
verbs (e.g., blows, makes, eats); the regular past tense of
verbs (e.g., looked, washed, talked); and the copula form of
the verb ‘to be’ (e.g., I am tired, They are mine, It is empty).
Each morphological structure was targeted for four
intervention sessions in total, two during each cycle of
therapy. Within the session, participants were encouraged to
attempt a range of words that used the target morpheme,
but no specific vocabulary list was prescribed for these
sessions. The purpose of the sessions that focused on
morphological structure was not to teach specific clusters
but to create a greater awareness of word endings and the
copula through exposure to a variety of words that included
the target morpheme. The morphosyntax sessions began
with auditory bombardment of the target morphological
structure in the context of a picture book. Focused
stimulation and elicited production activities were then
conducted in the context of group play activities. Feedback
included explicit modeling of the correct production of words
containing the target morpheme as is typical in language-
based approaches.
During the speech sessions, participants received
individualised targets: final consonant deletion for Matt and
velar fronting for Ben. No consonant clusters were targeted
during these sessions. The speech sessions followed a
similar format to the morphosyntax sessions with auditory
bombardment of the target sounds for the session in the
context of a picture book. This was followed by activities
that maximised opportunities for production practice of the
speech targets.
Main measures
Measure of cluster development
The 26-word cluster probe (see Appendix) was administered
at three different points in time: pre-intervention, immediately
post-intervention, and 3 months post-intervention. The
cluster probe that was administered immediately post-
intervention took place approximately 4½ months after
administration of the pre-intervention cluster probe.
Measure of additional target phonological
error pattern
Each participant was administered one of two 16-word
production probes at two different points in time: pre-
intervention, and immediately post-intervention. One
production probe measured accuracy of final consonants
and the other production probe measured accuracy of velar
stops in both word-initial position (n = 11) and word-final
position (n = 5). Pre-intervention accuracy on these
– velar fronting, gliding of /r/. From these phonological error
patterns, one additional intervention target was selected for
each child: final consonant deletion for Aaron and Matt, and
velar fronting for Mike and Ben.
General procedure
Participants attended a total of 24 therapy sessions (of at
least 45 minutes), two sessions a week, in groups of four
children in a university clinic setting. Four children who
participated in a larger study that investigated the efficacy of
two types of treatment for children with speech and
language disorder (Gillon & Tyler, 2007) were also involved in
the therapy sessions but were not included in this study as
they did not have difficulty producing consonant clusters.
Therapy was provided in two 6-week blocks, with a 6-week
break between treatment blocks. In the period between the
immediate post-intervention testing and the testing 3 months
post-intervention, participants did not receive any direct
intervention for the production of speech sounds but
continued with their regular early education program at
kindergarten or play centre. Intervention was implemented
by the third author and speech pathology students under the
supervision of a certified speech pathologist.
Intervention
Participants were randomly assigned to take part in one of
the two types of intervention: (1) integrated phonological
awareness and speech (PAS) intervention, or (2) a
morphosyntax and speech (MS) intervention. The PAS
intervention program (Gillon & McNeill, 2007) targeted
speech production, phonological awareness, and letter
knowledge, but not expressive language. The MS
intervention program (Haskill, Tyler, & Tolbert, 2001) targeted
various morphosyntactic structures and speech production,
but not phonological awareness. Both programs provided
therapy for the same frequency, length, and number of
sessions. A similar number of target words were introduced
for each speech target for both types of intervention. At least
10 attempts of the target phonological or morphological
structure were elicited from each child during each
intervention session. Parents, siblings, and/or caregivers
observed both types of intervention from observation rooms
behind one-way mirrors. Although there was no specific
home practice provided for either intervention program,
parents were not discouraged from practising target sounds
or activities at home. It should be noted, however, that the
children in the MS group received only 8 sessions that
included coda clusters (the target morpheme for four
sessions was the copula) whereas the children in the PAS
group received 12 sessions that targeted onset clusters.
Phonological awareness and speech intervention
The aim of the PAS intervention program was to facilitate
letter knowledge, and early phoneme awareness
development, and to decrease target speech error patterns.
(See
integrated_phonological_awareness.shtml for a detailed
discussion of the rationale and implementation of this
approach.) The phonological error pattern of reducing word
initial /s/ clusters was targeted for the first 6 weeks of
intervention. During the second 6-week block of therapy,
participants received individualised targets: final consonant
deletion for Aaron and velar fronting for Mike. Phonological
awareness instruction was incorporated into the speech
production activities in many of the session activities. For
example, within the same activity, participants were