Effect of simultaneous bilateral cochlear implantation in prelingually deaf children

Humans can hear with two ears, after which a central integration of the
perceived sound occurs. This is often called binaural hearing. Therefore, one
is able to locate sound. This enables the listener to focus on the sound source
and to determine quickly on which side possible danger originates from.
Binaural hearing can also reduce the negative influence of disturbing sounds on
speech perception, which consequently improves the speech perception.

Patients with severe to profound deafness, who are provide with a unilateral
cochlear implant (CI), are unable to hear binaurally. Literature shows improved
speech perception as well as localisation in children with bilateral CIs
compared to listening with a unilateral CI [Sparreboom M et al. The
effectiveness of bilateral cochlear implants for severe to profound deafness in
children: a systematic review. Accepted for publication 2010]. However, in the
Netherlands, the provision of bilateral CIs is not standard health care. As the
majority of prelingual deaf children with a CI without additional handicaps
attend to mainstream school settings, the consequence of unilateral fitting is
a serious matter of concern. Research showed that school-age children with
several degrees of unilateral hearing loss were at risk for speech-language
delays and educational grade failures [Lieu, 2004]. As a result of improved
speech perception in noise, it is expected that the advantage of bilateral CIs
can be particularly found in the possibility to learn incidentally. In
prelingually deaf children with a unilateral CI this is generally more
difficult.

In 2009 the Dutch Health Care Insurance Board indicated that at this moment the
available evidence is not sufficient enough to approve the advantage of
bilateral cochlear implantation in children compared to children with a
unilateral CI. They indicate that reconsideration will occur if publications
from Dutch origin become available on speech perception and the acquisition of
spoken language in children with prelingual severe to profound hearing loss
with bilateral CIs.

To assess the effect of bilateral cochlear implantation compared to the
standard unilateral cochlear implantation in children with severe to profound
hearing loss.

Observational study

Subjects will be investigated once, in which they will not be at any risk and
the burden for the subject will be very small. Parents will fill in
questionnaires with regard to the psychosocial functioning of their child. As
the study aims on development, which occurs during the first years of life, the
study will be administered in minors. As the Dutch Health Care Insurance Board
have approved the initiative for the intended study, we feel that, in the light
of the very small burden for the children, the study is justified.