ACQ Vol 12 no 1 2010

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ACQ Volume 12, Number 1 2010 55
(including breathiness) and different states of vocal
adduction. Generally, the voice acoustic characteristics of
speakers with stroke-related dysarthria were similar to those
of healthy ageing speakers – a surprising finding.
The results from this study suggest that the effects of
stroke on the voice are minimal compared to the effects
of aging. It is possible, though, that subgroups exist with
more serious vocal pathology. The results may therefore
be a conservative indication of the degree of impairment,
and do not address the concomitant impact on activity and
participation in daily living. However, they demonstrate the
importance of using a combination of both perceptual and
acoustic analysis in the clinical assessment of dysarthria
following stroke. Future studies will better enlighten the exact
profile of voice dysfunction in this group.
Functional characteristics of children
diagnosed with CAS
Teverovsky, E. G., Bickel, J. O., & Feldman, H. M. (2009).
Functional characteristics of children diagnosed with
childhood apraxia of speech. Disability and Rehabilitation,
31(2), 94–102.
Lara Lambert
Childhood apraxia of speech (CAS) is a severe childhood
speech sound disorder with difficulty in sequencing
movements required for speech production. In this article the
authors show that the International Classification of
Functioning Disability and Health – Children and Youth
(ICF-CY) can be used as a framework to describe the
functional characteristics of children with CAS. A total of 192
parents of 2- to 15-year-old- children with CAS were asked
to fill in a survey consisting of 61 items. Apart from questions
tapping demographic information, including past or current
medical, developmental, and mental health issues, the
survey included 43 items based on the World Health
Organisation’s systematic description of how young children
function in the home and school contexts (i.e., their body
functions, performance of daily living activities and social
participation). Through descriptive statistics and exploratory
factor analysis, four main factors were identified within the
broad range of functional problems in children with CAS:
1) cognitive and learning problems included learning through
play, literacy (learning to read, spell and write), calculations in
numeracy, and memory; 2) social communication difficulties
comprised comprehension of verbal and non-verbal
messages, undertaking a task, and interpretation of context
(including danger), as well as producing a non-verbal
message; 3) behavioural dys-regulation encompassed
management of behaviour, temperament, and emotions,
which influence performance in educational and social
environments; 4) other oral motor problems included
difficulties with eating and drinking.
The authors’ self-critique of limitations of the study
include its dependence on parental reports of diagnoses
and descriptions and its non-representation of lower
socioeconomic families. However, the ICF design on which
the study was based has been constructed to minimise
cultural and linguistic bias and has been field tested.
While speech sound difficulties in young children may
resolve, learning and social challenges may persist and
the functional analysis using the ICF-CY may be useful for
a multidisciplinary team in assessment, intervention, and
monitoring of children with CAS.
amplification with loud speech to establish the most effective
method of communication.
The intelligibility of habitual, loud, and amplified speech
in five speakers with Parkinson’s disease was assessed by
reading 20 sentences under each of the above conditions.
These speech samples were then randomised, and listeners
were asked to rate the intelligibility of sentences. Acoustic
analysis was also performed. Results demonstrated a
significant effect for stimulus type, with loud sentences
deemed more intelligible than amplified ones, which were in
turn more intelligible than the habitual sentences. There were
also direct changes observed in phonatory and articulatory
behaviour with increased vocal effort. This suggests that
increased intensity alone accounts for some, but not all,
improvements in intelligibility with vocal effort.
In order to determine which phonatory and articulatory
changes contribute to better intelligibility ratings, a word
transcription task was used to focus on potential phonetic
changes. Loud words were transcribed more accurately than
amplified words, and amplified words were transcribed more
accurately than habitual ones.
Overall, the article provides evidence that there are
benefits in both loud speech and amplification for dysarthria
in Parkinson’s disease. Changes in articulation contribute to
increased intelligibility in loud speech. Careful documentation
of changes in articulation, resonance, voice quality, and
prosody during treatment is recommended to demonstrate
how these changes affect listeners, as it appears that other
aspects aside from simple loudness need to be addressed.
Future research could possibly examine prosody and voice
quality more closely. The possibility of any carryover effects
to the swallowing mechanism as a result of increased
vocal effort would present another relevant opportunity for
investigation.
Acoustic voice analysis in dysarthria
following stroke
Wang, Y., Kent, R., Kent, J., Duffy, J., & Thomas, J. (2009).
Acoustic analysis of voice in dysarthria following stroke.
Clinical Linguistics and Phonetics, 23(5), 335–347.
Kylie Mulcahy
As speech pathologists, we understand our clients with
dysarthria in a multitude of ways. In those with stroke-related
dysarthria, however, the exact profile of underlying
involvement is often difficult to demarcate with evidence of
laryngeal hypo- and hyper-function existing. This study
conducted by reputable authors aims to establish the profile
of voice dysfunction in stroke-related dysarthria, using
objective instrumental analysis of voice. The authors
hypothesised that participants with stroke-related dysarthria
would have differing phonatory abilities when compared
against young and elderly speakers.
A total of 61 individuals (diagnosed with dysarthria
following stroke) provided speech samples for analysis,
from which 15 acoustic parameters were obtained. These
were compared with normative data from previous literature
across three gender-split groups (speakers with stroke,
healthy elderly speakers, and healthy young speakers).
Results indicated that the primary acoustic effect of stroke
on both the male and female voice is an increased noise
measure (soft phonation index). Although the exact clinical
applicability of soft phonation index is unclear, it has been
shown to correlate perceptually with various dimensions