Effects of Asymmetric Auditory Deprivation in Sequential Cochlear Implant

Eduardo S Farinazzo; Rubens V de Brito Neto; Elisabete H Yamaguti; Marco A Fornazieri; Luiz F M Lourençone

doi:10.1002/ohn.70308

Effects of Asymmetric Auditory Deprivation in Sequential Cochlear Implant

Otolaryngol Head Neck Surg. 2026 Jun 3. doi: 10.1002/ohn.70308. Online ahead of print.

Authors

Eduardo S Farinazzo¹, Rubens V de Brito Neto², Elisabete H Yamaguti¹, Marco A Fornazieri³, Luiz F M Lourençone^{1

4}

Affiliations

¹ Cochlear Implant Section and Department of Otolaryngology, Hospital for Rehabilitation of Craniofacial Anomalies, University of São Paulo, Bauru, Brazil.
² Department of Otolaryngology, University of São Paulo School of Medicine, São Paulo, Brazil.
³ Department of Otolaryngology, State University of Londrina, Londrina, Brazil.
⁴ Departament of Medicine, Bauru School of Medicine-FMBRU/USP, Bauru, Brazil.

PMID: 42233584
DOI: 10.1002/ohn.70308

Abstract

Objective: To evaluate the influence of auditory deprivation on sequential cochlear implants in postlingual patients, comparing the ear with shorter deprivation (ESAD), longer deprivation (ELAD), and the bilateral condition (BIL).

Study design: Retrospective study.

Setting: A tertiary referral center.

Methods: Postlingually deafened patients who underwent sequential bilateral implantation between 1990 and 2021. Auditory performance was assessed over 24 months after activation of each implant. Outcomes included free-field pure-tone average (PTA), speech detection threshold (SDT), and sentence recognition in quiet and in noise at +10 dB SNR. Secondary variables were interimplant interval, duration of preimplant hearing aid use, etiology, and electrode insertion depth.

Results: ESAD outperformed ELAD in quiet (73% [IQR 44-92] vs 37% [IQR 0-87]) and in noise (27% [IQR 0-62] vs 0% [IQR 0-45]) at 24 months (P < .001). BIL achieved superior results to both monaural conditions in quiet (97% [IQR 72.5-100], P < .001) and in noise (57% [IQR 23-86.5], P = .008), regardless of ESAD experience. Interimplant interval correlated positively with BIL performance (r = 0.450; P < .001). Longer hearing aid use was negatively associated with ESAD (r = -0.293; P = .020) and BIL performance (r = -0.312; P = .018). Partial electrode insertion in ELAD was linked to poorer BIL outcomes in quiet (P = .045). No correlations were found for age or etiology.

Conclusion: Shorter auditory deprivation and interimplant intervals are associated with better outcomes. Bilateral stimulation enhances performance even with long deprivation in 1 ear, and auditory experience with the first implant improves results. Complete insertion favors the more deprived ear, whereas prolonged ineffective hearing aid use may compromise outcomes.

Keywords: auditory deprivation; sequential cochlear implant; speech recognition.