The human ear consits of outer-, middle-, and inner ear:


The acoustical waves propagating in the air put the eardrum into movement. This movement is transfered to the small bones attached to the other side of the eardrum. They lead the sound as mechanical movement into the inner ear. Here waves which propagate on the basilare membrane are generated. The real organs of sense are connected to the basilare membrane -


the hair cells (Fig. left). They transfer the mechanical movement by means of a chemical process into nerve signals. These nerve signals use complex paths to move to higher stages of the auditory system. Some use a direct path and others are combined with paths from the opposite ear.