Cognitive load. One mechanism which has been hypothesized to link hearing loss and cognitive decline is the idea of cognitive load. In other words, when you can’t hear well, the ear is constantly sending a garbled auditory signal to the brain. Does the brain constantly have to work harder to process that poor signal? Is the brain reallocating resources, per se, to constantly dealing with that garbled auditory signal and does it come at the expense of other systems?
In 1973, Danny Kahneman put forth his model of cognitive resource capacity (Kahnerman, 1973). Cognitive resource capacity is the idea that we have a pool of cognitive resources for thinking, planning, memory. We now know that over time with aging, we can lose some of these resources from things such as synaptic loss of the brain. Increasingly, we are beginning to understand that a hearing loss likely taxes the system as well. The brain is constantly having to re-allocate resources to help with deciphering and decoding that much more garbled auditory signal.
