The human auditory system evolved with a right-ear advantage as speech processing required more of the brain.
Written by esteemed industry guru in July 2017, James Jerger, explains how the auditory system is not symmetrical, and that due to evolutionary requirements, the right and left side’s of our brains have diverged to work somewhat differently. Some of the most interesting points are that;
in 20yr olds with normal hearing there is a 3-5% advantage in the ability to process speech information that is input to the right side, compared to the left, and that this asymmetry increases as we age, up to 37% at age 80yrs
as humans developed speech and language and the requirement to interpret them, we needed to perform two main tasks; a) vowels and consonants b) the prosody of speech, like emphasis, intonation and rhythm
the left hemisphere (right ear) took on the complex former role and the right hemisphere (left ear) took the lesser
the Corpus Callosum that connects left and right hemispheres may cause binaural interference, increasingly so as we age
Age-related Corpus Callosum deterioration, such as a decrease in size, fiber composition, white matter and metabolism is likely to exacerbate the right-ear advantage and may be the reason why (all factors being equal) some elderly clients prefer to be fitted with just one device in the right than being fitted with two.
Ensure that you and your loved ones are advised by a professionally trained and independent Audiologist to ensure getting the best objective information and recommendations.