APD may be genetic (having a tendency to occur in families) or it may be congenital (a child may have undergone some stress or difficulty in-utero that induced APD).  APD can also relate to deprivation.  Children who are not adequately exposed to speech sounds and listening experiences typically encountered by young infants and children may not develop appropriate listening skills and abilities.  This may occur as a result of a medical or social condition that deprives a child of consistent or expected auditory input.  Considerable data suggests that children who experience frequent middle ear infections, which are accompanied with middle ear fluid and hearing loss, during critical auditory development periods (such as the first and second years of life) may suffer such deprivation.  APD may also be present as a result of neuro-maturational delays.  The ability to recognize and separate sounds in the environment requires training via learning experiences.  If a child's neurological system is not sophisticated enough to take advantage of the experiences of life a child will not develop a fully functional and integrated auditory system.  APD may also be acquired as a result of head injury or metabolic disorders.

In adults, APD may occur as a result of illness or injury. Stokes, psychiatric disorders, and head injuries have been associated with deficits in auditory processing.

In addition to auditory processing disorders directly or indirectly related to the auditory nervous system or systems that modulate listening, there are children who experience weaknesses in auditory processing as a result of more global processing disorders.  For instance, children with autism spectrum disorders have problems processing sensory information.  They may have difficulty with visual perception, tactile perception, as well as auditory perception.  Thus, a child with an autism spectrum disorder may have difficulties with auditory perception, but that child is a very different child than one who has a more focused auditory processing disorder.  Both require intervention to treat the listening problem, but the approaches may be quite different.

Additional areas that are frequently confused with APD, or stronly influence listening, are Attention Deficit Disorder (ADD) and Language Processing Disorder (LPD). Due to the brief and competitive nature of sound, if children are not actively attending to and enaged with a sound signal they may not be able to properly recognize, discriminate, and effectively process the acoustic signal. Language Disorders impact speech sound recognition and discrimination, word processing and retrieval, and a host of other linguistic elements that receive information from and feedback information to the auditory system.