Cochlear implants in adults: outcomes in prolonged auditory deprivation

To evaluate outcomes following cochlear implantation (CI) in postlinguistically deaf adults with prolonged auditory deprivation.

A retrospective analysis was conducted on 95 patients who underwent CI between 2020 and 2022. Inclusion criteria were age ≥18 years. Main outcome measures included the pure-tone average across speech frequencies (PTA4), speech perception scores (monosyllabic words and sentences), and the Categories of Auditory Performance II (CAP-II). Correlation and regression analyses examined associations between auditory deprivation and postoperative outcomes, adjusting for confounders such as age at implantation and prior hearing aid use.

Mean PTA4 improved by 70.8 dB HL, with median 100-word and 100-sentence recognition scores of 82% and 84%, respectively. Patients with ≥30 years of deprivation showed significantly lower CAP-II scores (p = 0.015). Linear regression revealed a modest inverse relationship between duration of deafness and tonal gain (-0.331 dB per year). Among participants under 65 years, prolonged deprivation correlated with reduced tonal gain and CAP-II scores, whereas no such effect was observed in older adults. Age at implantation influenced monosyllabic word recognition but not sentence perception.

Findings indicate that the consequences of auditory deprivation are more pronounced in younger adults, likely reflecting increased vulnerability of central auditory processing when hearing loss occurs earlier in life.

Cochlear implantation provides substantial benefits across age groups. Prolonged auditory deprivation exerts a greater impact in adults under 65 years, supporting early implantation and continuous auditory stimulation to preserve central auditory processing and optimize long-term outcomes.