The aim of the article is a presentation of symptoms of invalid auditory processing and its influence on brain functions, as well as bringing attention to use of that knowledge in therapeutic processes. In children, signs of invalid auditory processing occur in the form of various difficulties in learning, dyslexia, speech and diction disorders, weakened muscle tone, as well as lack of confidence. In adults, the signs are poor speech intelligibility, slurred speech, and insecurity. Those symptoms can accompany other disorders, such as: autism, Asperger syndrome, or depression. Knowledge on this topic and familiarity with the therapeutic influences are helpful in conducting proper therapy. I will discuss briefly the theory of Professor Alfred Tomatis, the inventor of Auditory Integration Training, and the concept of the impact of music on brain development, as well as the creator of a new trend called Audio-Psycho-Phonology.