Benefits of cochlear implantation across the adult life-span

Benefit from CI may vary according to age and other factors. We collected demographic and patient-reported hearing performance data from an observational study (IROS) and from an online questionnaire. Firstly, the 49-question Speech Spatial Qualities (SSQ49) questionnaire was administered to 543 unilaterally implanted adults across Europe, South Africa and South America. Data were collected at preoperatively and 1 to 3 years postoperatively. Degree of deafness in each ear and hearing history were collected. Secondly, the short-form 12- question SSQ12 questionnaire was administered to 2231 cochlear implanted patients across Europe. For both groups, the presence of tinnitus and dizziness were collected. SSQ49 scores varied systematically between age ranges, most notably between subjects aged <45 and those 55 or older. However, gains in SSQ scores between baseline at preoperative visits and Year 1 follow up after implantation were approximately equivalent across age groups and remained stable up to 3 years. We noted that the older groups had lower levels of hearing loss compared with younger groups, yet had overall lower scores at all time points. SSQ12 scores were subjected to regression tree analysis with breaks based upon patient demographics. Overall, younger patients (<70yrs) with no tinnitus reported significantly higher speech-subcale scores than older patients or those with tinnitus. Bilateral implantation gave higher spatial-subcale scores and higher sound clarity (question 11) and reduced listening effort (question 12) irrespective of age. The presence of tinnitus was also associated with higher listening effort. Cochlear implantation was equally effective in terms of gains in hearing-related quality of life (SSQ) across the adult life span. The novel use of regression tree analysis revealed that both advanced age and the presence of tinnitus reduced self-reported speech recognition performance. Bilateral cochlear implantation provided better spatial hearing and clarity, but not better speech recognition in real-world situations