Sensory deprivation

March 25, 2012 by Jessica Tremblay

La privation sensorielle

It is common for those suffering from hearing loss, and the people in their lives, to underestimate this problem, in light of the embarrassment they may endure as a result of existing prejudices. Hearing-impaired individuals wait an average of seven years before seeking professional help. Not only does that long wait force them to struggle with daily hearing difficulties, but depriving themselves of proper hearing also has repercussions on their entire auditory system, from the ear to the brain. This situation is referred to as sensory deprivation.

Our nervous system, including the brain, has the capacity to adapt and change the way it organizes its functions. This is referred to as brain plasticity. The more information the brain receives from a specific part of the body, the more effectively it processes that information. So if a part of the human body begins sending fewer messages than before, the nervous system’s ability to process that information correctly diminishes. When a person experiences deafness in an ear, the quantity and quality of the messages sent to the brain is effectively reduced, and in turn, the auditory system’s pathways from ear to brain are used less frequently.

Sensory deprivation leads to a decline in the brain’s ability to recognize and understand speech, a problem that can grow worse over time. This condition can affect people of any age, and is found in hearing-impaired individuals who don’t wear a hearing aid, as well as in those with hearing loss in both ears who wear only one hearing aid. In the latter case, sensory deprivation is experienced in the unfitted ear.

If diagnosed and treated in time, comprehension difficulties can be alleviated, which is why it is critical not to wait until hearing problems become unbearable before taking action. To improve speech intelligibility, stimulation of the auditory system must be increased as soon as possible.

Hearing aids can reduce the auditory system’s sensory deprivation in two ways. In the short term, they improve speech intelligibility through better audibility, by amplifying words. Then, in the long term, they improve sound representation thanks to perception. Hearing aids continuously solicit auditory system pathways, helping maintain their effectiveness. Remember, your ears work all day long: even when you are asleep, they continue to send messages to your brain.In this fashion, amplification helps recreate the wealth of auditory input we receive every day. Obviously, brain plasticity cannot be regained overnight with auditory stimulation: it’s a gradual process that varies from person to person. Bear in mind that people have an average of seven years of sensory deprivation to make up for!

For further information, please don’t hesitate to consult an audiologist at a Lobe Santé auditive et communication multidisciplinary clinic.

References:

– ARLINGER, S. “Negative consequences of uncorrected hearing loss — a review”, International Journal of Audiology (2003); 42(2), 17–20.

– CORNA, L. et al. “Corrected and uncorrected hearing impairment in older
Canadians”, Gerontology (2009); 55, 468–476.

– FRISINA, R. and J. WALTON. “Age-related structural and functional changes in the cochlear nucleus”, Hearing Research (2006); 216–223.

– KAPPEL, V. et al. “Plasticity of the auditory system: theoretical considerations”, Brazilian Journal of Otorhinolaryngology (2011); 77(5), 670–674.

– PALMER, C. et al. “The functionally and physiologically plastic adult auditory
system”, Acoustic Society of America (1998); 103(4), 1705–1721.

– PHILIBERT, B. et al. “The auditory acclimatization effect in sensorineural hearing-impaired listeners: Evidence for functional plasticity”, Hearing Research (2005); 131–142.