Hearing preservation in 41 cochlear implant recipients with preimplant low-frequency residual hearing.
TL;DR
Hearing preservation remains a worthwhile surgical objective but was not associated with improved long-term speech recognition, and speech recognition remained robust irrespective of retained functional residual hearing.
Abstract
Background
Hearing preservation (HP) is an important objective in cochlear implantation for patients with residual low-frequency hearing, but its long-term clinical relevance remains uncertain.
Objective
To evaluate long-term hearing preservation, functional residual hearing, and speech recognition following cochlear implantation. MATERIAL AND
Methods
This retrospective cohort study included 41 adults (42 ears) with a preoperative low-frequency pure-tone average (LFPTA) ≤80 dB HL. Hearing preservation was assessed using the HEARRING and low-frequency threshold shift (dPTA) classifications. Linear mixed-effects models evaluated longitudinal changes in LFPTA and speech recognition, and Kaplan-Meier analysis estimated retention of functional residual hearing.
Results
Hearing preservation was frequently achieved according to both classification systems. LFPTA deteriorated by 20.5 dB HL during the first 6 postoperative months and declined by 2.46 dB HL annually thereafter (p = 0.020). Functional residual hearing decreased from 66.7% to 41.7% during follow-up. In contrast, speech recognition improved significantly after implantation (all p < 0.001) and remained stable. Retained functional residual hearing was not associated with superior speech recognition.
Conclusions
AND
Significance
Although residual hearing declined progressively, speech recognition remained robust irrespective of retained functional residual hearing. Hearing preservation remains a worthwhile surgical objective but was not associated with improved long-term speech recognition.