The next sensory system we will cover is the auditory system. The ear is able to detect sound due to the changes in air pressure that occur as a sound source vibrates. The frequency of vibrations depends on the distance between successive patches of dense air. The higher the frequency of sound waves, the higher the pitch that is detected.
Sounds can also vary in intensity, which is reflected as loudness.
The tympanic membrane detects vibrations in the air, and causes the ossicles to vibrate. The ossicles amplify and relay the signal from the tympanic membrane to the oval window. The cochlea Behind the oval window is the fluid-filled cochlea. The cochlea is a hollow structure with a spiral shape. In cross section, the cochlea is divided into three chambers, the scala vestibuli, scala media and the scala tympani.