Auditory Processing Disorder (APD): Progress in Diagnostics So Far.  A Mini-Review on Imaging Techniques. 
Auditory processing disorder (APD) is a disorder that affects the perception of sound, both verbal and non-verbal.  Patients who are generally diagnosed with APD present with abnormal hearing but have normal audiograms.  There is no gold standard investigation for APD and no standardized criteria for diagnosis.  Because of its disabling effect and the overlap that exists with other neurodevelopmental disorders, there is an urgent need to develop tools and criteria for appropriate diagnosis.  There is a current significant focus in research on imaging techniques that can possibly be used in the future for the appropriate diagnosis of APD.  Over the years, several imaging techniques have contributed significantly to defining this disorder.  To date, no studies have reported the routine use of imaging for the diagnosis of APD.