References
Influencing factors
Motivation and commitment
1. SSD: “In addition to intensive modified rehabilitation programs, the patient’s motivation was shown to be definitely decisive in our study” (Arndt et al. 2017)
Influencing factors
Hours of use
1. “Daily device use was documented for 24 patients with CNC word data and 21 patients with BKB-SIN data. Figure 1 (right panel) plots performance as a function of daily device use. There was a significant association for CNC words (r(24)=0.56, p=0.002) and BKB-SIN (r(21)=-0.49, p=0.012), with better performance observed with increases in daily device use.” (O‘Rourke et al. 2025)
Influencing factors
Emotional status
Influencing factors
Cause of hearing loss
1. “The postoperative performance with a cochlear implant (CI) highly varies among patients. Patient-specific factors that are associated with postoperative speech perception are 1) the preoperative speech perception (1), 2) the duration of hearing loss (2,3), 3) the etiology of hearing loss (4), and 4) the age at implantation (5,6).” (Breitsprecher et al. 2023)
Influencing factors
Duration of auditory deprivation
1. “The postoperative performance with a cochlear implant (CI) highly varies among patients. Patient-specific factors that are associated with postoperative speech perception are 1) the preoperative speech perception (1), 2) the duration of hearing loss (2,3), 3) the etiology of hearing loss (4), and 4) the age at implantation (5,6).” (Breitsprecher et al. 2023)
2. “Some considerations should be taken among the duration of hearing deprivation, and/or the period of inadequate stimulation, as these are reported to negatively influence the outcome of hearing rehabilitation by several authors, as expected.” (Ciorba et al. 2019)
Influencing factors
Presence of medical comorbidities
1. “Comorbidities as assessed by ACE-27 are associated with CI performance. Patients with more severe comorbidities have clinically meaningful improvement but have worse outcome compared to patients with no comorbidities.” (Dang et al. 2024)
Influencing factors
Presence of cognitive comorbidities
Influencing factors
Pre-op benefit with hearing aids
1. “Speech comprehension with hearing aid at 80 dB can be used as a supplementary preoperative indicator of CI-aided speech comprehension and should be measured regularly in the clinical routine. […] WRSmax and WRS80(HA) were better predictors of CI-aided comprehension than was preoperative speech comprehension at 65 dB with HA.“ (Rieck et al. 2023)
Influencing factors
Pre-op hearing
1. “WRSmax [unaided maximum word recognition] and WRS80(HA) were better predictors of CI-aided comprehension than was preoperative speech comprehension at 65 dB with HA.“ (Rieck et al. 2023)
Influencing factors
Pre-op vocabulary
Influencing factors
Pre-op speech comprehension
1. “Speech comprehension with hearing aid at 80 dB can be used as a supplementary preoperative indicator of CI-aided speech comprehension and should be measured regularly in the clinical routine. […] WRSmax and WRS80(HA) were better predictors of CI-aided comprehension than was preoperative speech comprehension at 65 dB with HA.“ (Rieck et al. 2023)
Influencing factors
Electrode length
1. “Electric CI stimulation of the spiral ganglion apex in the second cochlear turn, combined with TFS (FS4), enables clear low-frequency perception and enhances speech in noise (SPIN) and music quality. This supports the rationale to use 28-, 31- or 34-mm electrodes with apical TFS (FS4), offering near normal hearing quality.” (Van de Heyning 2025)
2. “While the FLEX20 ES [Electric Stimulation-only] and FLEX24 ES groups were still in their learning phase between the 3 to 6 months interval, the FLEX28 ES group was already reaching a performance plateau at the three months appointment yielding remarkably high test scores.” (Büchner et al. 2017)
3. “Seven studies found no significant correlation between insertion depth and speech perception outcomes (9,22,31,37,41,42,44).
Fifteen studies reported a positive effect or significant positive correlation between insertion depth and speech perception (11,13,29,30,32–36,38–40,43,45,46) (Table 2).” (Breitsprecher et al. 2023)
4. “Longer electrode insertions (and greater insertion angles) appear to offer better speech perception performance in the early postactivation period when using the same implant system.” (Buchman et al. 2014)
Influencing factors
Structure and hearing preservation
1. “Hearing preservation has been shown to confer the following audiologic benefits: better speech understanding in complex listening environments, superior sound localization, and improved music appreciation.” (O’Connell et al. 2017)
Influencing factors
Natural sound quality of the CI
1. “Higher sound quality ratings were associated with better QOL [Quality Of Life] outcomes. The strongest correlations with sound quality were observed in the communication domain (r = 0.65, p < 0.001), followed by the listening effort and emotional domains (both r = 0.50, p < 0.001), then the environment domain (r = 0.46, p < 0.001), while the entertainment (r = 0.39, p < 0.001) and social domains (r = 0.35, p < 0.001) demonstrated relatively weaker, though still significant, correlations.” (Berg et al. 2025)
Influencing factors
Tinnitus reduction
1. “Electrical stimulation via a CI resulted in a significant reduction in tinnitus loudness (mean ± SD; 1 year after implantation, 2.4 ± 1.8; 2 years after implantation, 2.5 ± 1.9; before implantation, 8.5 ± 1.3). With the device deactivated, tinnitus loudness was still reduced to between 6.1 and 7.0 over 24 months. The Tinnitus Questionnaire revealed a significant positive effect of CI stimulation.” (Van de Heyning et al. 2008)
Influencing factors
Post-op balance issues
Influencing factors
Access to medical support in case of a problem
1. “The user must have open access to the CI center (or a designated local partner service) for rehabilitation and counseling as required. To allow progress to be monitored, appropriate standardized audiological, speech perception, and quality of life measures should be performed after initial tuning; this should be done at least twice but preferably 4 times […] in the first year following implantation and at regular intervals thereafter. After the first year following implantation, the user should be offered an annual audiological review.” (Távora-Vieira et al. 2020)
Influencing factors
Early awareness
Influencing factors
Early assessment
1. “Waiting times for diagnostic testing and treatment should be as short as possible and comply with current national and local targets. Current HEARRING targets are 6 weeks for diagnostic and 18 weeks for treatment.“ (Távora-Vieira et al. 2020)
Influencing factors
Early intervention
Influencing factors
Early fitting
1. “Thus, early fitting not only enhances immediate auditory outcomes but also contributes to sustained and increased usage of the device, promoting better long-term developmental outcomes. Early fitting is safe and feasible for many patients. This approach allows for earlier rehabilitation and may have long-term benefits for stimulation levels and dynamic range.” (Almuhawas et al. 2025)
2. “No major or minor complications were reported and all patients could perform the early fitting. Activation modality influenced impedance values only in the short term but the differences were not statistically significant (p > 0.05). Mean MCL values in the early fitting group were lower than MCL of the late fitting in all follow-up sessions, and the difference was statistically significant (p < 0.05). The mean PTA was lower in the early fitting group but the difference was not statistically significant (p < 0.05).“ (Soncini et al. 2024)
Influencing factors
Early rehabilitation
1. “The IG [Intervention Group: Group that had been activated much earlier than the Control Group] achieved better results 7 weeks after implantation and completion of rehabilitation, both at quiet and with background noise, than the CG [Control Group] after 15 weeks (at the start of rehabilitation). This is relevant for situations in everyday life. The results thus prove that the Frankfurt concept provides CI patients with the benefit of the CI significantly earlier and thus achieves an earlier improvement in speech perception.” (Bruschke et al. 2024)
2. “Early fitting of cochlear implants is safe, allows for an early rehabilitation and can have possible beneficial effects on stimulation levels and dynamic range.” (Soncini et al. 2024)
3. “Systematic postoperative rehabilitation should begin after initial fitting according to the individual needs of the user, to:
1. Facilitate acclimatization to the new sensation of sound and the integration of the CI with the contralateral acoustic ear. Extensive rehabilitation and training of the CI ear alone-for instance, through a direct signal input to the audio processor-is mandatory.
2. Reassure the user and their family/caregiver.
3. Outline the rehabilitation program.” (Távora-Vieira et al. 2020)
4. “Thus, early fitting not only enhances immediate auditory outcomes but also contributes to sustained and increased usage of the device, promoting better long-term developmental outcomes. Early fitting is safe and feasible for many patients. This approach allows for earlier rehabilitation and may have long-term benefits for stimulation levels and dynamic range.” (Almuhawas et al. 2025)
Influencing factors
Rehab
1. “Recent meta-analyses and systematic reviews demonstrate that AR is safe and effective in both adult and pediatric populations. Computer-based auditory training (CBAT) is the most common rehabilitation modality reported in the literature. In adult patients, there is evidence that both computer-based and in-person AR strategies improve speech perception outcomes.“ (Harvey et al. 2024)