Deafblindness is one of the least understood of all disabilities. “The deaf-blind child is not a blind child who cannot hear or a deaf child who cannot see.” (Deaf-Blind Infants and Children, J.M. McInnes & J.A. Treffry, 1982)
Either a hearing loss or a vision loss alone has a significant impact on learning and development. A child with a vision loss – must rely more upon hearing to compensate for the lack of available visual information. A child with a hearing loss – must rely more upon vision to compensate for the lack of available auditory information. The important thing is that for these children, one of their distance senses will compensate for the lack of the other one.
For children with both vision and hearing loss, neither sense can adequately compensate for the lack of the other. The natural flow of visual and auditory information does not happen. Bits and pieces of information may be available, but these will be incomplete, distorted, and/or unreliable. The incidental information that sighted and hearing children receive without effort is not readily accessible to those with combined losses.
Deafblindness creates a disability of access to the visual and auditory information about the environment (people, things, events) that is necessary for learning, communication, and overall development. Instead of effortlessly receiving a flow of information like others, these students must work to attend, gather, and interpret partial amounts of information which are often distorted and incomplete. Without clear and consistent information, the brain cannot function normally and learning cannot occur naturally. As a result, students who are deafblind have a difficult time connecting with and understanding the world, and often experience significant isolation and limited opportunities for self-determination (Alsop, Blaha, & Kloos, 2002; Robinson et al., 2000).
The impact of these combined losses on each student varies, depending on the:
- degree and type of vision and hearing losses
- stability of the losses
- age of onset of each loss
- presence or absence of additional disabilities
- quality of educational services provided
It is critically important to understand that the student’s vision and hearing losses are not additive in nature (deafness plus blindness), but rather are multiplicative (deafness times blindness). Therefore, sometimes even students with seemingly mild simultaneous vision and hearing losses can be greatly impacted by them (Huebner, Prickett, Welch, & Joffee, 1995; McInnes & Treffry, 1982).
Deafblind Simulations
20/400 Acuity Loss with Fragmentary Profound Hearing Loss
20/400 Acuity Loss with Precipitous Hearing Loss
Light Perception only with Profound High Frequency Hearing Loss
Hemianopsia and Oculomotor Problems with Precipitous Hearing Loss
Simulation of Multiple Losses
