Physics of Sound : A Handbook for Students of High School

The ears are also vital for maintaining balance. The inner ear contains the vestibular system a part of the body that is largely responsible for spatial orientation and the coordination of movement as they relate to balance.Three small fluid-filled loops called semicircular canals sit just above the cochlea. One detects up-and-down movement the next detects side-to-side movement and the third detects tilting.The fluid in the semicircular canals shifts when a person moves their head. These canals also contain thousands of tiny sensitive hairs which bend as the fluid flows past them. This bending relays information to the brain about the type of movement.When a person spins around and stops suddenly the fluid keeps moving for some time continuing to push against the hairs. The hairs continue to send messages to the brain so the brain assumes that the person is still spinning. This is dizziness.A vestibule joins the semicircular canals and the cochlea. It contains two sacs called the utricle and the saccule which send the brain information about how the head is moving in relation to gravity and acceleration.For instance the saccule helps a person tell whether they are traveling up or down in an elevator and more importantly whether they are lying down or standing up.This Handbook includes worksheets solved questions class notes and familiar terms related to sound.