JOURNEY THROUGH THE EAR

Untitled Slide

Untitled Slide

Untitled Slide

Untitled Slide

Untitled Slide

Untitled Slide

Untitled Slide

HOW WAVE PROPERTIES CHANGE PERCEPTION

• amplitude- determines intensity (volume) of sound
• wavelength- determines the pitch of sound
• Amplitude and Wavelength are properties of sound waves

THE NEURAL JOURNEY OF SOUND

• After transduction, nerve cells send neural messages
• to the brain through the auditory nerve.
• The thalamus routes this sensory info to the
• auditory cortex in the temporal lobes.

HELMHOLTZ'S PLACE THEORY

• Different pitches due to the types of sound waves and
• where they causs vibrations on the basilar membrane.
• Does not explain how we hear low-pitched sounds
• High frequency = large vibration at start of membrane
• Low frequency = small vibration at end of membrane

FREQUENCY THEORY

• Vibrations of the basilar membrane transmit neural impulses
• The speed of the vibration causes pitch
• Lower notes = slow vibrations, higher notes = fast vibrations
• Tone with frequency=250 waves per second
• 250 neural impulses per second

VOLLEY PRINCIPLE

• Neurons alternate when firing
• While one is firing, another is preparing
• Allows neurons to achieve combined frequency
• Enables us to hear high frequency sounds

THANK YOU!

Untitled Slide