The National Center for Evidence-Based Practice
in Communication Disorders
Home      Review-699

Summary of Systematic Review

Bilateral Cochlear Implantation: An Evidence-Based Medicine Evaluation
Murphy, J., & O'Donoghue, G. (2007).
Laryngoscope, 117(8), 1412-8.

This review meets the criteria for a high-quality evidence-based systematic review.

Indicators of Review Quality:

The review states a clearly focused question or aim No
Criteria for inclusion of studies are provided Yes
Search strategy is described in sufficient detail for replication Yes
Included studies are assessed for study quality Yes
Quality assessments are reproducible Yes
Characteristics of the included studies are provided Yes

Description:
This is a systematic review of the literature investigating the outcomes associated with bilateral cochlear implantation in children and adults with hearing loss.

Question(s)/Aim(s) Addressed:
Question not specifically stated.

Population:
Children and adults with bilateral cochlear implants.

Intervention/Assessment:
Bilateral cochlear implants.

Number of Studies Included:
37

Years Included:
up to 2006.

Conclusions:

Adult Hearing Loss

  • Treatment

    • Implantable Devices

      • Cochlear Implants

        • Unilateral/Bilateral

          • There is a “substantial improvement in the localization acuity of bilateral over unilateral users” (p. 1417).

          • “From the available literature to date, there appears to be little doubt that speech intelligibility in a noisy environment is substantially improved with use of bilateral cochlear implants compared with use of only one” (p . 1417).

Permanent Childhood Hearing Loss

  • Treatment

    • Cochlear Implants

      • Placement

        • “Comparisons within the pediatric group are difficult because of the small number and varieties of studies…The limited available data suggest that not only is bilateral implantation more effective than unilateral or bimodal stimulation, but improved auditory abilities are seen if the implantations are performed simultaneously. However, bimodal stimulation should not be dismissed because this can provide significant benefits from the additional pitch and timing information of the acoustical input in those patients with residual hearing in the contralateral ear” (p. 1418).

        • "The available evidence supports the current trend toward bilateral cochlear implantation. None of the studies found a disadvantage in using a second implant, and all of the studies demonstrated, to varying degrees, that the auditory ability investigated was materially improved by binaural hearing” (p. 1418).

    • Hearing Aids

      • General Findings

        • “Comparisons within the pediatric group are difficult because of the small number and varieties of studies…The limited available data suggest that not only is bilateral implantation more effective than unilateral or bimodal stimulation, but improved auditory abilities are seen if the implantations are performed simultaneously. However, bimodal stimulation should not be dismissed because this can provide significant benefits from the additional pitch and timing information of the acoustical input in those patients with residual hearing in the contralateral ear” (p. 1418).

School-Age Hearing Loss

  • Treatment

    • Implantable Devices

      • Cochlear Implants

        • Unilateral/Bilateral

          •  “Comparisons within the pediatric group are difficult because of the small number and varieties of studies…The limited available data suggest that not only is bilateral implantation more effective than unilateral or bimodal stimulation, but improved auditory abilities are seen if the implantations are performed simultaneously. However, bimodal stimulation should not be dismissed because this can provide significant benefits from the additional pitch and timing information of the acoustical input in those patients with residual hearing in the contralateral ear” (p. 1418).

          • "The available evidence supports the current trend toward bilateral cochlear implantation. None of the studies found a disadvantage in using a second implant, and all of the studies demonstrated, to varying degrees, that the auditory ability investigated was materially improved by binaural hearing” (p. 1418).

        • Bimodal Amplification

          • “Comparisons within the pediatric group are difficult because of the small number and varieties of studies…The limited available data suggest that not only is bilateral implantation more effective than unilateral or bimodal stimulation, but improved auditory abilities are seen if the implantations are performed simultaneously. However, bimodal stimulation should not be dismissed because this can provide significant benefits from the additional pitch and timing information of the acoustical input in those patients with residual hearing in the contralateral ear” (p. 1418).

Sponsoring Body:
Not stated.

Keywords:
Deafness, Hearing Loss, Cochlear Implants

» Access the Review