Transcript Phonological Contrast Approach to Therapy

Phonological Contrast
Approach to Therapy
Barbara Dodd
Phonological Contrast
Intervention
• 8O% of children with speech impairment
respond positively to this type of therapy.
Delay and Consistent Disorder
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By linguistic definition, phonology concerns
language specific knowledge of phonemes
and how they may be combined to make up
words.
Children who have delayed phonology are
slow to abstract the constraints of their
phonological system
Children using atypical error patterns have
difficulty accurately abstracting information
about their phonological system (poor PA,
literacy, atypical errors)
Intervention target selection
• phonological error pattern
• stimulable versus non-stimulable sounds
• developmental sequence or promoting
intelligibility
• disordered versus delayed
• inconsistent versus consistent errors
How contrasts are targeted:
• minimal pairs - sounds differing by one
distinctive feature – voicing /p/ vs /b/, place /t/
vs /k/ or manner /n/ vs /d/ (least knowledge)
vs
• maximal pairs -(sound differing on all three
dimensions e.g. /f/ vs /g/; /m/ vs /s/ (most
knowledge
• Many contrasts within a phonological error
pattern (eg, for final consonant deletion pie,
pipe, pine, pile, pies);
• multiple oppositions across a phoneme
collapse (e.g. where /d/ is substituted for all
Approaches to delivery of the
intervention:
-Specific intervention paradigms (Cycles;
Auditory Bombardment)
- Methods of teaching and reinforcing
feedback: specific, graded
Child specific choices
-Nature of words used in intervention
-Materials used.
-Decision criterion (80%, 90%)
Case Study:
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Luke, age 4;10,
No previous intervention
Identified by his preschool teacher
Normally developing except for speech
No parental concerns regarding any other
aspect of development.
• Receptive language and oro-motor skills
were age-appropriate.
• Hearing was within normal limits
• No significant history of hearing difficulties.
Initial Assessment and Baseline
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Unintelligible.
Consistent (12% inconsistency)
PCC of 45%
No vowel errors.
Imitated all sounds in syllables except /th/
(age-appropriate)
• Error patterns
– age-appropriate
– delayed
– atypical error patterns.
Initial assessment: continued
– Deleted all final consonants except nasals
– Reduced all consonant clusters to a single
consonant
– Backing of /t/d/ to /k, g/ in syllable-initial
positions
– Deletion of all affricates in syllable-initial
position
– Re-assessment after three weeks showed no
significant spontaneous change in PCC 46%
Intervention Approach
• A minimal pair approach (sometimes with
multiple oppositions) was used to reorganise Luke’s phonological system.
• The homonymy in Luke’s system was
directly exposed to show him that he was
failing to contrast meaning adequately.
• The minimal pairs were selected to target
specific error patterns.
Intervention Goals
• To mark all final consonants (not necessarily
with the correct consonant – but with a final
sound present)
• To correctly contrast t/d from k/g
• To mark both elements of two consonant
clusters (again not necessarily with the
correct consonants – but with two sounds
present)
These goals were chosen
because:
• relative effect on intelligibility – final
consonant deletion was considered to be
affecting Luke’s intelligibility the most;
atypical pattern
• targeting atypical before developmental error
patterns – backing is not an error pattern
normally developing children use
• all speech sounds were stimulable (except
/th/) – therefore this factor did not effect the
choice of intervention goals
Intervention Paradigm
• Sixteen, 30-minute, twice weekly, individual
intervention sessions over a nine-week
period.
• Each week one of the sessions was
conducted at Luke’s preschool and the other
at his home, facilitating communication
between the SLP and both Luke’s mother
and preschool teacher.
• Follow-up activities were conducted at home
and preschool – usually two 10-minute
practice sessions each day.
Each error pattern was targeted
in four stages:
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auditory discrimination
single words
phrases (set and then spontaneous)
sentences within conversation.
Criteria for therapy sequence:
• A 90% accuracy training criterion (based on
the final 20 productions of target items
elicited in the session) was required
• When an error pattern moved to phrase
stage a new error pattern was introduced
(i.e. final consonant deletion then backing
then cluster reduction.
• Ten non-treated probe words were elicited at
the end of every second session to monitor
generalisation.
Results
• Speech accuracy increased from 45 to 67
PCC.
• Progress on the untreated generalisation
probes improved from:
-FC: 0/10 to 9/10– excluding nasals;
-Backing: 0/10 to 7/10 – highly frequent
words
-Clusters: 0/10 to 6/10 - errors due to gliding
• Intelligible speech. Most errors residual gliding /r/ and /l/ to /w/, some fronting, /th/.