Answer :
The auditory system of human is divided into three regions:
1- Outer ear: the external ear and ear canal;
2- Middle ear: end of the ear canal and begin of the cochlea (transmit the sound vibration from the external environment to the cochlea);
3- Inner ear: coclea (responsible to transmit sound information to the nervous system).
All together are responsible for the arrival of the auditory signal to the nevous system.