Related Experiment Video
Updated: Feb 24, 2026
Systematic Hearing Performance Evaluation Process for Adolescents with Cochlear Implantation at Early Ages
Published on: March 24, 2023
Isolated Second Implant Adaptation Period in Sequential Cochlear Implantation in Adults
Kari Smilsky1, Peter R Dixon, Leah Smith
1*Department of Otolaryngology-Head and Neck Surgery, University of Toronto †Sunnybrook Cochlear Implant Program, Sunnybrook Health Sciences Centre ‡Department of Otolaryngology-Head and Neck Surgery, Sunnybrook Health Sciences Centre Toronto, Canada.
Objective:
To determine if depriving the use of the first cochlear implant (CI1) impacts adaptation to a sequential implant (CI2).
Study Design:
Prospective cohort.
Setting:
Academic center.
Patients:
Sixteen unilateral cochlear implant recipients undergoing contralateral implantation (sequential bilateral) were matched according to age, etiology, duration of deafness, device age, and delay between implants.
Intervention:
During a 4-week adaptation period after CI2 activation, patients underwent deprivation of CI1 or were permitted continued use of it.
Main Outcome Measures:
Speech perception scores and subjective quality of life outcomes before CI2 and at 1, 3, 6, and 12-months following activation.
Results:
Maximal CI2 speech perception scores in quiet were achieved by 1-month postactivation for the "deprivation" group (71.3% for hearing in noise test [HINT], p = 0.767 for change beyond 1-mo) compared with 6-months for the "continued use" group (67.9% for HINT, p = 0.064 for change beyond 6-mo). The "deprivation" group experienced a temporary drop in CI1 scores (67.9% for HINT in quiet at 1-mo versus 78.4% pre-CI2, p = 0.009) recovering to 77.3% by 3-months; unchanged from baseline levels (p = 1.0). A binaural advantage over the better hearing ear was present for HINT sentences with noise (72.4% versus 58.8% for "deprivation", p = 0.001; 71.5% versus 52.7% for "continued use," p = 0.01). Missing data precluded a meaningful analysis of subjective quality of life outcome scales.
Conclusion:
Bilateral cochlear implantation improves speech perception compared with one implant. A period of deprivation from CI1 shortens time to maximum speech perception by CI2 without long-term consequences on the performance of CI1.
