Communication effects of auditory deprivation

Binaural Summation

If auditory stimuli are received by other auditory areas, and not at the center of the brain. The brain cannot effectively process the stimuli.

Communication Effects of Auditory Deprivation

Binaural Summation

When a seventy decibel sound is introduced to each ear individually; and the seventy decibel sound is introduced to each ear at the same time, a summation of five to seven decibels is experienced—the same seventy decibel input sounds louder because of binaural auditory summation.


Binaural Summation

It is the goal of a hearing instrument specialist to create bilateral (both ear) stimulation correctly—correct electroacoustic stimulation should result in binaural summation.


Binaural Summation

Audiometric monaural (with masking) and binaural word recognition scores must be obtained to provide information regarding the patient/client residual hearing ability to achieve binaural summation.


Binaural Summation

We need to program their hearing instruments until they perceive their own voice, at BINAURALLY BALANCED MCL in the center of their head, to be located one inch in front of the center of their lower lip.


Binaural Summation

The Stenger affect says if you have identical signals in each ear and there is a 15db or greater PERCEIVED difference between the thresholds (at frequency), you think it is occurring only in the ear in which it is the loudest.


Binaural Summation

The Stenger effect holds true with bilateral HI stimulation. If the gain of the two hearing instruments cannot result in stimulation of each ear within 15 dB, then the brain only perceives and responds to the ear which has the greater stimulation. Summation cannot occur.


The ability to identify the binaural balance at MCL is critical to the successful fitting of hearing instruments. It facilitates improved communicative abilities and therefore, communicative skills. Any lower level of performance (on our part), denies the optimum potential for success.


Monaural remediation of

binaural problems is simply NOT ACCEPTABLE.

It does not permit for effective hearing, and therefore, does not facilitate efficient communicative skills and abilities.


Auditory Deprivation

In 1984, Silman, Silverman, and Gelfand published the results of a study in which they looked at the auditory behavior of veterans with hearing loss.



They divided the veterans into two groups. In one group they fit hearing aids in both ears. With the other group, they fit only one ear. They followed the performance of these two groups over a five year period.



Their findings demonstrated that word recognition scores for each ear in the group fit binaurally decreased less than two percentage points (2%) over the period.



In the group with only one hearing instrument (one aided ear), the word recognition score for the aided ear had a decrease consistent with the other group (less than two percentage points (2%) change).



They found in the unaided ear (which had not been aided for five years), that there was a significant decrease in the word recognition score over the same period. They measured that change to be almost 18%.



In 1990, Silverman published a follow-up study in which she addressed the question concerning the effect on discrimination when an instrument is fit to the previously unaided ear after three years of monaural fitting (figure 7).



Fig. 7 Three years—see below


In 1990, Silverman published a follow-up study in which she addressed the question concerning the effect on discrimination when an instrument is fit to the previously unaided ear after eight years of monaural fitting (figure 8).


Fig. 8 Eight years—see below



There was also age related data for those veterans over age sixty, which revealed that those under age sixty had better recovery from auditory deprivation than those over age sixty.



Silverman’s study shows clearly that, while there is some improvement in the word recognition scores, there IS NOT recovery to the level of the ear that has been continuously aided. This finding supports the idea that: "if you do not “use it” you will certainly "lose - some of it”.



The more the hearing loss, the greater the diminution of discrimination, and perhaps, the more permanent the effect!


A hearing instrument COULD help, but that more than one was "a waste of money”, historically, this statement was often made to prospective hearing instrument purchasers.


Current hearing instrument recommendations are to fit two instruments instead of just one higher technology—more expensive HI.


The capacity of the brain to selectively attend (listen to the message while suppressing consciousness of the noise) can only be accomplished in the binaurally balanced state (binaural summation).


The growing body of converging evidence of auditory deprivation effects and binaural interference suggests that, at the first sign of sensitivity loss, the elderly individual probably should be fitted immediately with binaural amplification.


It may very well be that early intervention can effectively counter the potentially serious deprivation effects resulting from lack of normal auditory stimulation.


Education

Communication effects of auditory deprivation