EOAD is a form of progressive hearing loss that can affect Rhodesian Ridgebacks. Some dogs lose their hearing as early as one to two years of age. 

Genetic basis 
The disease is associated with a recessive mutation in the EPS8L2 gene. 

Research
Dr. Neff's research lab at UC Davis (USA) was instrumental in identifying the genetic cause of EOAD in Rhodesian Ridgebacks. It is believed that the gene responsible for EOAD in the Ridgeback is most likely also responsible for a imilar deafness in humans. More specifically, the human genetics literature suggests that this particular form of deafness in humans affects children before they learn to speak. These children must face the challenges of communication throughout their lives. 

Test results 
The following results were obtained during the study phase:
EOAD - High confidence: affected (most likely to be affected)
EOAD - High confidence: carrier (most likely gene carrier)
EOAD - High confidence: clear (most likely clear)

In einigen Fällen waren die Ergebnisse auch nicht schlüssig. Sie wurden als „Highly informative subject: Inconclusive“ bezeichnet.

The test for the EOAD is a risk test.

Today's lab results are labeled as follows: 
N/N (clear) - the dog does not have an abnormal gene for EOAD
EOAD/N (carrier) - the dog has received the abnormal gene from one parent - it is not and will not become deaf, but it does carry the gene for EOAD.
EOAD/EOAD (affected) - the dog has received the abnormal gene from both parents - it is very likely to be deaf or will become deaf later.

Conclusion:
Since EOAD is an autosomal recessive inheritance, it is completely unproblematic to include carriers in breeding. Of course, they should only be bred to dogs that are free of EOAD, as this means that no EOAD-affected puppies can ever be born that later become deaf.