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JCPSLP
Volume 17, Number 3 2015
Journal of Clinical Practice in Speech-Language Pathology
The measures of adult word count (number of adult words
spoken near the child), conversational turn count (verbal
exchanges between an adult and the child occurring within
five seconds of each other), and child vocalisation count
(vocalisations at least 50 milliseconds in duration and
surrounded by 300 milliseconds of silence) were hypothesised
to differ between the groups. This hypothesis was non-
directional due to the limited and inconsistent findings from
the literature.
Method
Participants
Five children who were D/HH and their caregivers were
recruited from Telethon Speech and Hearing, a facility that
provides early intervention and specialist services for
children with speech, language, and hearing difficulties in
Western Australia. The children were fitted with a hearing
aid or cochlear implant. Five NH children and their
caregivers were recruited via the researchers’ informal
networks. The NH children were matched by hearing age
(plus or minus three months) and gender. Participant
matching by maternal education level (e.g., undergraduate
degree, trade qualification) was also attempted. See Table 1
for participant characteristics, and Table 2 for the nature of
intervention received by the D/HH children. All participants’
primary language at home was English. The NH children
passed an audiological screening at 25dB across the
frequencies of 500, 1000, 2000, and 4000 Hz in a quiet
room. Their language was deemed typically developing
(falling within one standard deviation of the mean) using a
52-question caregiver survey, the LENA Developmental
Snapshot, or three subtests of the Clinical Evaluation of
Language Fundamentals – Preschool (2nd ed.) if over 36
months of age. The LENA Developmental Snapshot
permitted time constraints to be adhered to, whilst
providing results highly correlated with other standardised
language assessments (see Gilkerson & Richards, 2008).
Ambrose, VanDam and Moeller (2011), toddlers who are D/
HH are exposed to approximately 1400 adult words per
hour. In a separate study, Hart and Riseley (1995) reported
that children who are NH from professional and working-
class families heard on average 1702 adult words per hour.
Contradicting this apparent discrepancy in the number of
words heard, VanDam et al. (2012) found that the D/HH
group (
N
= 22) and the NH group (
N
= 8) were exposed to
approximately the same number of adult words, and the
children who are D/HH did not participate less in
conversational turns. The resulting weaker expressive and
receptive language skills were attributed to the quality of the
conversational turns, in conjunction with the impact of the
hearing loss (Ambrose et al., 2011). This recent study
contradicts previous research noting disparities between
the populations (Lederberg & Mobley, 1990), causing the
language quantity in the HLE to be difficult to predict.
Aims
The current study had two aims: first, to compare the
quality of the HLE of children with and without hearing loss;
and second, to consider differences in quantitative
language measures recorded in the HLE, namely adult word
count, conversational turn count, and child vocalisation
count. It should be noted that previous studies had not
yielded conclusive findings, and there were often small
sample sizes and lack of detail regarding the measures.
With regards to parent and child responsiveness, it was
hypothesised that the D/HH child–caregiver dyad would
demonstrate less successful child and caregiver initiations,
fewer connected utterances, and more failed utterances.
Similarly, more behavioural directives and a decreased ratio
of successful child to caregiver initiations were expected,
indicating higher parental conversational control. Fewer
caregiver expansions were also expected, signifying a less
supportive linguistic environment.
Table 1. Participant characteristics of D/HH and NH children
Chronological age
months; days
Hearing age Hearing aid (HA) /
Cochlear implant (CI)
Mother’s education
level
Diagnoses
HI Female 1 38m; 14d
36m; 7d
HA from 2m; 7d, CI from
35m; 24d
Post graduate degree None
NH Female 1 33m; 7d
–
–
Bachelor degree
None
HI Female 2 51m; 3d
48m; 29d
HA (bilateral) from 2m; 5d
Post-graduate
degree
Possible oral motor weakness
affecting upper lip and lifting
of tongue
NH Female 2 47m; 27d
–
–
Bachelor degree
Mild stutter (<2% syllables
stuttered)
HI Male 3
42m; 1d
26m; 20d
CI from 14m; 11d
Diploma of education None
NH Male 3 28m, 4d
–
–
Bachelor degree
None
HI Male 4
35m; 1d
34m; 4d
HA from 27d
Senior secondary
education (Year 12)
Treacher Collins Syndrome
NH Male 4 33m; 3d
–
–
Trade qualification
None
HI Female 5 39m; 10d
31m
HA at approximately 8m; CI
(right) at 18m; 26d and (left)
at 43m
Did not provide
None
NH Female 5 29m; 28d
–
–
Post-graduate
degree
None