The human voice is a complex instrument that requires individual attention in order to perform efficiently and in a healthy manner. In essence , the basis of singing is the manipulation of an internal mechanism (that which we cannot see), which requires having a teacher with expertise in anatomy and physiology. In addition, outside ears are essential to learning to sing due to the fact that people hear mostly through bone conduction, and therefore, do not hear themselves as they truly sound. Equally important to the singing process is understanding of the "inner voice". How a singer thinks about his/her voice and his/her expectations of sound will enable the body to react in different ways.