Changes in Speech Intelligibility, Health-Related Quality of Life, Depressive Symptoms, Anxiety, Perceived Stress, and Tinnitus-Induced Distress, in a Cohort of 227 Adults One Year After Cochlear Implantation: A Decade of Experience from a Single Tertiary Center

Background/Objectives: The purpose of this study was to analyze changes in speech intelligibility, health-related quality of life, and the degree of comorbidities (depressive and anxiety symptoms and tinnitus-related distress) in a large cohort of 227 adults who underwent auditory rehabilitation with a cochlear implant (CI). The second goal was to identify the factors that influence the health-related quality of life in this cohort. Methods: Pre- and one-year post-CI data were collected on speech intelligibility (Freiburg Monosyllabic Test, FS), subjective hearing ability (Oldenburg Inventory, OI), health-related quality of life (Nijmegen Cochlear Implant Questionnaire, NCIQ), depressive symptoms (General Depression Scale, ADS-L), anxiety (Generalized Anxiety Disorder 7, GAD-7), perceived stress (Perceived Stress Questionnaire, PSQ), and tinnitus-related distress (Tinnitus Questionnaire, TQ). Results: The Wilcoxon matched-pairs signed-rank test showed significant improvements across the entire cohort in speech intelligibility, subjective hearing, and the quality of life. The scores indicating anxiety, depressiveness, perceived stress, and tinnitus-related distress decreased. The Spearman correlation showed that before implantation, quality of life positively related to subjective hearing, while depression, anxiety, stress, and tinnitus distress were negatively correlated. After a year, these links persisted but grew stronger. Regression analyses found subjective hearing (OI) as a positive predictor, and depression (ADS-L) and tinnitus distress (TQ) as negative predictors of life quality, especially in patients with low or median NCIQ scores. Conclusions: In a substantial cohort of adult patients with diverse CI indications, auditory rehabilitation enhances speech intelligibility and subjective hearing, improves health-related quality of life, and reduces the severity of depressive and anxiety symptoms, as well as tinnitus-related distress. Subjective hearing contributes positively to quality of life, whereas depressive symptoms and tinnitus distress negatively impact quality of life in patients with low NCIQ scores post-CI, highlighting the importance of monitoring and psychological intervention.