Plasticity After Hearing Rehabilitation in the Aging Brain

Area of Science:

• Neuroscience
• Audiology
• Gerontology

Background:

• Age-related hearing loss (presbycusis) is linked to cognitive decline and dementia.
• Presbycusis involves peripheral and central auditory impairments.
• Neural plasticity in the aging brain after auditory rehabilitation is not well understood.

Purpose of the Study:

• To investigate the effect of age at cochlear implantation on speech perception outcomes.
• To analyze long-term speech understanding trajectories in cochlear implant users.
• To identify factors influencing neural plasticity after auditory rehabilitation in older adults.

Main Methods:

• Reanalysis of a large dataset (>2200 users) of cochlear implant (CI) recipients.
• Assessment of speech perception improvements from 6 to 24 months post-implantation.
• Statistical analysis to determine the impact of age at implantation on CI outcomes.

Main Results:

• While CI rehabilitation improves speech understanding on average, age at implantation has minimal effect at 6 months but a negative effect at 24 months.
• Older individuals (>67 years) showed a higher likelihood of performance degradation after 2 years of CI use compared to younger patients.
• Three plasticity trajectories (Awakening, Counteracting, Decline) were identified, explaining performance disparities.

Conclusions:

• Age at cochlear implantation significantly influences long-term speech perception outcomes.
• Older adults may experience performance degradation despite auditory rehabilitation.
• Behavioral interventions may be crucial to enhance auditory network reactivation in aging brains.