The use of cochlear implants can result in remarkable improvement in the ability to understand speech. Despite the dramatic successes enjoyed by many cochlear-implant users across the lifespan, the outcomes can be variable, and some individuals continue to struggle when trying to participate in conversations, especially older adults. While young children are often highly successful with cochlear implants, they have different cognitive processing than adults, and might benefit from different CI programming strategies. We are exploring ways of improving cochlear implant programming and listener strategies across the lifespan.
As the overall population ages, the number of older adults who use cochlear implants is increasing rapidly; therefore, it is critical to understand how aging might effect performance with cochlear implants. The effects of aging and hearing loss extend beyond the ear and are associated with changes at multiple levels of the brain. Restoration of hearing at the level of the auditory nerve through cochlear implantation may not be sufficient to overcome degeneration in auditory processing at higher levels of the auditory system.
Because of potential changes to the auditory system in older adults, it is important to consider alternate approaches to programming cochlear implants that would maximize performance. One key factor in decreased performance may be an age-related decline in temporal processing that would affect the ability to localize sound, discriminate between subtle timing differences between words, and understand speech in noise. Changes in the brain’s ability to process the rapidly changing temporal components of speech may limit the benefits experienced by individuals who use cochlear implants. We are combining different assessments to better understand the interacting effects of aging and duration of deafness on auditory temporal processing and the subsequent impact on speech understanding. Our participants perform a variety of listening tasks using either tones, words, or sentences, while the timing characteristics of either the task or the cochlear implants are manipulated to determine effects on temporal processing. We also use objective electrophysiological measures to better understand the aspects of brain processing that contribute to differences in behavioral performance. The outcomes of this study should provide the audiologist with more guidance for optimizing cochlear-implant fittings and improving speech perception and quality of life in the older cochlear-implant user.
Young children (such as toddlers) might likewise benefit from different CI programming strategies than are used by young adults. We are investigating how aging interacts with cochlear implant programming; this may provide evidence for improved CI programming, or for new training methods for listeners of different ages. Such outcomes will provide a significant positive impact on hearing and understanding speech with a CI, which will increase CI users' quality of life.