Auditory processing disorder and rarely known as King-Kopetzky syndrome or auditory disability with normal hearing (ADN) is an umbrella term for a variety of disorders that affect the way the brain processes auditory information. Individuals with APD usually have normal structure and function of the outer, middle, and inner ear (peripheral hearing). However, they cannot process the information they hear in the same way as others do, which leads to difficulties in recognizing and interpreting sounds, especially the sounds composing speech. It is thought that these difficulties arise from dysfunction in the central nervous system. Auditory processing disorder and rarely known as King-Kopetzky syndrome or auditory disability with normal hearing (ADN) is an umbrella term for a variety of disorders that affect the way the brain processes auditory information. Individuals with APD usually have normal structure and function of the outer, middle, and inner ear (peripheral hearing). However, they cannot process the information they hear in the same way as others do, which leads to difficulties in recognizing and interpreting sounds, especially the sounds composing speech. It is thought that these difficulties arise from dysfunction in the central nervous system. The American Academy of Audiology notes that APD is diagnosed by difficulties in one or more auditory processes known to reflect the function of the central auditory nervous system. It can affect both children and adults. Although the actual prevalence is currently unknown, it has been estimated to be 2–7% in children in US and UK populations. APD can continue into adulthood. Cooper and Gates (1991) estimated the prevalence of adult APD to be 10 to 20%. It has been reported that males are twice as likely to be affected by the disorder as females, and that prevalence is higher in the elderly and increases with age. Many people experience problems with learning and day-to-day tasks with difficulties over time. Adults with this disorder can experience the signs and symptoms below: It has been discovered that APD and ADHD present overlapping symptoms. Below is a ranked order of behavioral symptoms that are most frequently observed in each disorder. Professionals evaluated the overlap of symptoms between the two disorders. The order below is of symptoms that are almost always observed. This chart proves that although the symptoms listed are different, it is easy to get confused between many of them. There is a high rate of co-occurrence between AD/HD and CAPD. An article published in 1994 showed that 84% of children with APD have confirmed or suspected ADHD. Co-occurrence between ADHD and APD is 41% for children with confirmed diagnosis of ADHD, and 43% for children suspected of having ADHD. more recently published data is needed to support or refute this statement. There has been considerable debate over the relationship between APD and Specific language impairment (SLI). SLI is diagnosed when a child has difficulties with understanding or producing spoken language for no obvious cause. The problems cannot be explained in terms of peripheral hearing loss. The child is typically late in starting to talk, and may have problems in producing speech sounds clearly, and in producing or understanding complex sentences. Some theoretical accounts of SLI regard it as the result of auditory processing problems. However, this view of SLI is not universally accepted, and others regard the main difficulties in SLI as stemming from problems with higher-level aspects of language processing. Where a child has both auditory and language problems, it can be hard to sort out cause-and-effect. Similarly with developmental dyslexia, there has been considerable interest in the idea that for some children reading problems are downstream consequences of difficulties in rapid auditory processing. Again, cause and effect can be hard to unravel. This is one reason why some experts have recommended using non-verbal auditory tests to diagnose APD. Specifically regarding the neurological factors of dyslexia, the disorder has been linked to polymicrogyria which causes cell migrational problems. This relates to APD because children that have polymicrogyri almost always present deficits on APD testing. It has also been suggested that APD may be related to cluttering, a fluency disorder marked by word and phrase repetitions. It has been found that a higher than expected proportion of individuals diagnosed with SLI and dyslexia on the basis of language and reading tests also perform poorly on tests in which auditory processing skills are tested. APD can be assessed using tests that involve identifying, repeating or discriminating speech, and a child may do poorly because of primary language problems. In a study comparing children with a diagnosis of dyslexia and those with a diagnosis of APD, they found the two groups could not be distinguished. obtained similar findings in studies comparing children diagnosed with SLI or APD. The two groups had very similar profiles. This raises the worrying possibility that the diagnosis that a child receives may be largely a function of the specialist they see: the same child who would be diagnosed with APD by an audiologist may be diagnosed with SLI by a speech-language therapist or with dyslexia by a psychologist.