Does Auditory Environment Predict Speech Perception Outcomes in Elderly Cochlear Implant Patients?

Introduction: Cochlear implantation (CI) is a reliable and safe means by which sensorineural hearing loss can be ameliorated in the elderly population. However, a high degree of variation exists in postimplantation hearing outcomes for which some modifiable factors of the daily natural auditory environment may be contributory. In this study, we analyze the relationship between cochlear implant patient age, natural auditory environment, and postimplantation speech perception among older adults. Methods: Data log from automatic environment classification enabled sound processors of postlingually deafened CI recipients >= 50 years old (n = 115) were obtained retrospectively and analyzed for time spent (hours per day) in listening environment and loudness (SPL dB). Speech perception testing was assessed in a subset of patients (n = 27) using open-set word recognition in quiet Consonant-Nucleus-Consonant in the short and intermediate postoperative period. Results: The mean subject age was 70 years (range, 53-99 years). Average daily implant use was 10.8 h and was not significantly correlated with age (p = 0.23, Spearman's rho). Age was positively correlated with the percentage of hours spent at <40 and 40-50 dB and negatively correlated to proportional CI use at higher volume (60-70, 70-80, and >80 dB; r(s) = 0.21, 0.20, -0.20, -0.35, -0.43; p = 0.021, 0.036, 0.033, <0.001, <0.001, respectively). Age was positively correlated with CI use in the quiet scene (r(s) = 0.26, p = 0.006) and negatively correlated with scenes containing speech and noise (r(s) = -0.19, -0.25; p = 0.046, 0.007). Total hours of device use and time spent at <40, 40-50 dB, and quiet environments were significantly correlated with improved CNC word scores (r(s) = 0.48, 0.48, 0.51; p = 0.01, 0.01, <0.01, Spearman's rho). While all speech (speech in noise + speech) was not significantly correlated to improvements in speech perception, a medium effect size was observed (r(s) = 0.37, p = 0.057). Discussion/Conclusion: This study supports a relationship between auditory environment and age, with older CI recipients spending a greater proportion of time in quiet. Older CI users demonstrated greater improvements in speech perception with longer daily device use. Additional examination of the relationship between auditory environment and speech perception is necessary to conclusively guide future auditory rehabilitation efforts.