Results for individual tests

PPVT For the 118 children who

completed the PPVT, the EA was 3.77

years (range 1.80 to 11.40 yrs; SD 1.80).

The average DELAY was 2.34 years

(range -1.90 to 8.00; SD 1.51).

Early Language Outcomes For Children Receiving Implants Under Three Years

Shani Dettman2,3, Yien Ching Ang1, Jaime Leigh1,3, Jennifer Holland1,3, & Richard Dowell1,2,3

1. The University of Melbourne, Dept of Otolaryngology

2. The Cooperative Research Centre for Cochlear Implant and Hearing Aid Innovation

3. Cochlear Implant Clinic, Royal Victorian Eye and Ear Hospital, Melbourne, Australia

Objective

Increasing numbers of infants and young children are being diagnosed and referred to

early intervention programs and implant centres as a result of widespread

implementation of neonatal hearing screening programs and greater awareness and acceptance of cochlear implant efficacy. As more cochlear implants are fitted in pre-

verbal children, early language checklists and scales have been used to determine

whether language is developing normally. Although research tends to support the

validity of checklists as screening tools in normal hearing populations, their sensitivity

in detecting pre-verbal children with significant hearing loss who require specialist

intensive language training remains to be demonstrated.

Results for individual tests

CDI For the 24 children who completed

the CDI, the Equivalent Age (EA) was

1.82 years (range 1.00 to 4.00 yrs; SD

0.75). The average DELAY was 0.93

years (range -2.38 to 3.91yrs; SD 1.45).

RI-TLS For the 92 children who

completed the RI-TLS, the EA was 0.78

years (range 0.00 to 3.00 yrs; SD 0.82). For the 89 children who had two or more

PPVT measures, the EA was 3.85 (range 1.80 to 11.40; SD 1.88) and the average

growth RATE was 0.93 (range -0.23 to

3.60; SD 0.62)(Figure 2 below).

intensive language training remains to be demonstrated.

So that language intervention can take place at the earliest possible time, it is important to determine whether scales and checklists used for infants are correlated

with, or even predictive of later vocabulary and language development in toddlers and

pre-schoolers.

Study DesignThis study examined the validity, clinical utility and

correlation of two infant checklists (Rossetti Infant –

Toddler Language Scale [RI-TLS; n=92] and the

Child Development Inventory [CDI; n=24]),

against a formal receptive vocabulary measure;

Peabody Picture Vocabulary Test of Receptive Language

[PPVT; n=118] for children receiving cochlear implants

under three years of age.

Subjects

This retrospective study examined language outcomes for 141 children who received

their cochlear implant(s) at the Royal Eye and Ear Victorian Hospital, Melbourne

Australia. There were 125 children with congenital hearing loss and 24 children who

had a later onset of hearing loss with the mean onset of hearing loss being 0.16 years

(range 0.00 to 2.40 yrs; SD 0.44). Children who had any evidence of progressive

hearing loss were excluded from the study. The mean 3 frequency pure tone average

Results across the three language tests

Significant correlations were found between the degree of delay measured by the

years (range 0.00 to 3.00 yrs; SD 0.82).

The average DELAY was 1.40 years

(range -0.47 to 6.46 yrs; SD 0.94). For

the 66 children who completed two or

more RI-TLS, the EA was 0.79 years

(range 0.00 to 3.00 yrs; SD 0.83) and the

average growth RATE was 0.82 (range

0.00 to 2.43; SD 0.54) (Figure 1 below).

Figure 1. Individual growth rates for 66 children who

completed two or more administrations of the RI –TLS.

PPVT n=118

CDI n=24

RI-TLS n=92

22

71

10

13

Figure 2. Individual growth rates for 89 children who

completed two or more administrations of the PPVT

0.00

1.00

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4.00

5.00

6.00

0.00 1.00 2.00 3.00 4.00 5.00 6.00

Chronological Age (years)

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Mean slope = 0.82

0

2

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14

0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0

Chronological age (years)

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(ye

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Mean slope = 0.93

hearing loss were excluded from the study. The mean 3 frequency pure tone average

was 113 dB HL (range 70 to 125 dB HL; SD 11.45) for the better ear. The mean age

at diagnosis was 10 months with mean age of hearing aid fitting at 1.01 years (range

0.10 to 2.60 yrs; SD 0.52) and mean age at cochlear implantation at 1.75 years (range

0.53 to 2.98; SD 0.62).

The speech processing strategies included ACE or SPEAK with Sprint, ESPrit 3G or

Freedom speech processors. The mean duration of cochlear implant experience was

2.73 years (range -1.58 to 11.85 yrs; SD 2.55).

Children were included if they had a fully functional current speech processing device,

no significant oro-motor dysfunction, English as the predominant language used at

home, and used a communication mode with either aural/oral (n=101) or sign

emphasis (n=36) at home or at school. There were four children where the

classification of communication mode was unknown. Most of the children (n=102) had

average cognitive ability as assessed by an Educational Psychologist. Any children

with poorer than ‘borderline average’ cognitive skills (n=8) were excluded.

PPVT and RI-TLS (n=71; r = 0.792; p<0.001), PPVT and CDI (n=13; r = 0.792; p<0.05)

and RI-TLS and CDI (n=22; r = 0.852; p<0.001).

For the 10 children who completed all three

language assessments, the average

Language growth RATE was 0.90

(range 0.50 to 1.50; SD 0.36)(Figure 3 right).

To estimate the degree of PPVT delay from RI–TLS delay and CDI delay, the

regression equations were as follows;

PPVT delay = 0.46 + 0.70 RI –TLS delay (R2 = 0.63)

PPVT delay = -0.33 + 1.21 CDI delay (R2 = 0.63)

The results of the regression analyses suggested a significant relationship between the

PPVT delay and the RI-TLS delay and CDI delay. The R2 values indicated that

approximately 63% of the variance in the PPVT delay was predicted by either the RI-

TLS delay or the CDI delay.

Summary and Conclusions

Correlation between child demographic/developmental variables and

language outcomes

As may be expected, the age at which a child received hearing aids was correlated

with the age at cochlear implant surgery (r = 0.53; p<0.001), and general device

experience effects were seen. That is, greater experience with the device was

associated with better outcomes for the RI-TLS (r = 0.715; p<0.001) and PPVT (r =

0.00

1.00

2.00

3.00

4.00

5.00

6.00

0.00 1.00 2.00 3.00 4.00 5.00 6.00

Chronological Age (years)

Eq

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(yea

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From this study, the children who received cochlear implants before the age of three

years demonstrated a RI-TLS language growth rate and PPVT language growth rate of

0.82 and 0.93 respectively. Normal hearing children demonstrate a growth rate of 1.00,

so these results for children with congenital and early onset profound hearing loss are

quite promising.

Results suggested that the infant checklists (RI-TLS and CDI) were well correlated with

the receptive vocabulary test (PPVT). Children using cochlear implants, who

demonstrated some degree of delay on the CDI or RI-TLS, would also be likely to

demonstrate delays on the PPVT. The CDI and RI-TLS are quite useful to monitor

language development in very young children with profound hearing loss and are

appropriate for clinicians to use when providing feedback to parents. Clinicians can

use these checklists to help parents form realistic expectations and plan appropriate

language goals for children with significant hearing loss.

Acknowledgements to

Children and Families, Speech Pathologists,

Audiologists, Surgeons & Administration Staff of

the Cochlear Implant Clinic, Royal Victorian Eye

and Ear Hospital, Victoria, Australia.

dettmans@unimelb.edu.au

associated with better outcomes for the RI-TLS (r = 0.715; p<0.001) and PPVT (r = 0.774; p<0.001) respectively. Significant correlations between the child’s chronological

age at the time of language testing and the RI-TLS equivalent age (r = 0.574; p<0.001)

and the PPVT equivalent age (r = 0.775; p<0.001) suggest that language performance

improves over time.

Of greater interest to this study were the relationships between communication mode

and language outcomes. Results from all three language measures were poorer for

children enrolled in programs with sign emphasis versus oral/aural emphasis. Significant correlations were found between sign communication used at home/school

and the RI-TLS (r = 0.369; p<0.001), CDI (r = 0.640; p<0.001) and PPVT (r = 0.198;

p<0.001). This result is complicated by the finding that communication mode at school

was also correlated (r = 0.19; p<0.001) with the cognitive status of the children. Taken

together, results suggest that children with borderline and low average cognitive skills

were more likely to be found in early intervention programs with sign emphasis and

were more likely to demonstrate greater language delays.

There was a significant relationship between the age at receiving the cochlear implant

and the degree of delay on the RI-TLS (r = 0.650; p<0.001) and PPVT (r = 0.431;

p<0.001). Similarly, duration of profound hearing loss was significantly associated with

the degree of delay on the RI-TLS (r = 0.569; p<0.001 and PPVT (r = 0. 404; p<0.001).

These results support the ‘earlier is better’ argument regarding the use of cochlear

implants for infants with significant hearing loss.