The auditory cortex is the part of the brain that processes sensory information in the form of sound. While the area is not directly or completely responsible for the hearing, it is essential to processing and understanding sounds. Other organs, such as the cochlea, have a more direct role in actually collecting the sound, which is also referred to as auditory information. If a person lacks the ability to process sounds, however, the noise seems to be jumbled and meaningless. In some cases, those who suffer damage to this part of the brain are completely unaware of sound, though they can still react reflexively to loud or sudden sounds as there is some level of auditory processing that occurs below the cortex.
Two different areas make up the auditory cortex, each of which has a slightly different function. The first section is the primary cortex; it is involved in most of the higher level processing that takes place in sound processing and is essential for recognizing when sound starts, stops, and changes pitch. The peripheral cortex tends to play a secondary role and is involved in more subtle processing processes.
While even those who have suffered damage to the parts of the brain required for auditory processes display reflex responses to loud sounds, they lack the ability to hear and understand many things that are extremely important, especially to humans. Speech, for example, is only understood through the collaboration of many different types of neurons involved in detecting when sound starts, when it stops, and what its pitch is. There is no precise rule of timing in speech, so these auditory neurons are of the utmost importance. Even more than speech, music requires a great deal of auditory processing as its artistic value often comes from changes in pitch and timing. There are many different parts of the human brain that work together to ensure that one can detect and understand speech and music with all of its subtleties.
There are many neurons in the auditory cortex that contribute to the ability to process and understand sound. Specific neurons send off electrical impulses to other parts of the brain when they detect a specific sound or pattern of timing. Some neurons fire when a sound begins, and others fire when it ends. There is a whole range of neurons that fire when they detect sounds of a certain pitch. The cortex contains all of these nerves and ensures that sound comprehension is a smooth and efficient process.