Hearing
Exploring our ability to distinguish,
identify, and locate sound.
Psychology & Period #
Olsen
Date
Group Names
Contents
 Introduction & Basic information
 Characteristics of Sound

Pitch & frequency

Locating sounds
 Hearing Loss & Deafness
 Vocabulary
 Activity: Label the part of the ear
 Group Activities/ active involvement activities

Guess that sound!

In the middle

Auditory Acuity

Two ears are better than one
 Hearing Quiz
 Quiz Key
 Sources
Introduction & Basic info
Hearing (or audition) is highly adaptive; we can hear a wide range of sounds at varying frequencies, as well
as are able to easily detect differences between sounds, such as different voices, instruments, animals, etc. The
speed of sound in 750 miles per hour, yet we are also able to detect the direction from which it came from by which
ear the sound waves hit first, as well as the intensity of the sound, as the difference may be.
When an object makes a noise sound waves travel through the air, and are funneled into your ear canal
through your outer ear. The vibrations move into your middle ear hitting your eardrum, causing it to vibrate as the
sound waves do. This brings a chain of vibrations continuing first to the hammer, then the anvil, then the stirrup. The
stirrup passes the vibrations into the cochlea (a coiled tube in the inner ear) which finally causes the basilar
membrane to move changing the vibrations in messages sent to the brain via the auditory nerve, which will make
sense of what you are hearing.
Characteristics of sounds
Pitch and Frequency
The strength or amplitude of sound waves determines the loudness. Sound waves also vary in length or
frequency. Long waves have low frequency and low pitch, as opposed to short waves with high frequency and high
pitch (the tone’s highness or lowness).
Place theory presumes that we hear different pitches because different sound waves trigger activity at
different places along the cochlea’s basilar membrane; the brain can determine a sound’s pitch by the place on the
membrane which it receives the neural signals. This is in opposition to Frequency theory, which suggests that the
whole basilar membrane vibrates with incoming sound waves, triggering our neural impulses to the brain at this same
rate.
Locating Sounds
Sound travels at 750 miles per hour, although despite this speed our ears are able to detect the difference
of which ear receives the sound first, and more intensely with a time difference of just .000027 seconds. With this we
are able to detect which direction various sounds are coming from, such as if a horn honks on the right as opposed to
the left, or if a phone is ringing, where in the room it is coming from.
Locating sound that is equidistant from both ears (such as behind, above, below, or in front of you) are
slightly more difficult to distinguish automatically being that the sound waves hit both ears at the same time.
Hearing Loss & Deafness
The ear’s structure is delicate and vulnerable to damage. Hearing loss is linked to conduction and nerve
disorders, and can be caused by prolonged exposure to loud noise and diseases, as well as age related.
Problems with the mechanical system, which conducts sound waves to the cochlea causes “conduction
hearing loss.” If the eardrum is punctured or if the tiny bones in the middle ear lose the ability to vibrate, the ear will
not be able to conduct the necessary vibrations to process the sound waves. Digital hearing aids can be used to
improve this.
Damage to the cochlea’s hair cell receptors or their associated nerves can cause “sensorineural hearing
loss,” this is also called nerve deafness. This can be caused by disease on occasion, but is generally due to genetic
causes. The National Center for Health Statistics estimates that 1% of people are born deaf; Cochlear implants can
enable hearing in deaf children at times; those who live with hearing loss often face social challenges.
Vocabulary
Audition: Sense of hearing.
Frequency: The number of complete wavelengths that pass a point in a given time.
Pitch: A tone’s highness or lowness; depends on frequency.
Middle Ear: The chamber between the eardrum and cochlea containing three tiny bones (hammer, anvil, stirrup) that
concentrate the vibrations of the eardrum on the cochlea, semicircular canals, and vestibular sacs.
Cochlea: A coiled, bony, fluid-filled tube in the inner ear through which sound waves trigger nerve impulses.
Place Theory: The hearing theory that links the pitch we hear with the place where the cochlea’s membrane is
stimulated.
Frequency Theory: The hearing theory that the rate of nerve impulses traveling up the auditory nerve matches the
frequency of a tone, thus enabling us to sense its pitch.
Conduction hearing loss: Hearing loss caused by damage to the mechanical system that conducts sound waves to
the cochlea.
Sensorineural hearing loss: Hearing loss caused by damage to the cochlea’s receptor cells or to the auditory
nerves; also called nerve deafness.
Cochlea : A spiral-shaped, fluid-filled inner ear structure; it is lined with cilia (tiny hairs) that move when vibrated and
cause a nerve impulse to form.
Eardrum: (also called the tympanic membrane) a thin membrane that vibrates when sound waves reach it.
Eustachian tube: A tube that connects the middle ear to the back of the nose; it equalizes the pressure between the
middle ear and the air outside. When you "pop" your ears as you change altitude (going up a mountain or in an
airplane), you are equalizing the air pressure in your middle ear.
Hammer : (also called the malleus) a tiny bone that passes vibrations from the eardrum to the anvil.
Anvil: (also called the incus) a tiny bone that passes vibrations from the hammer to the stirrup.
Stirrup: (also called the stapes) a tiny, U-shaped bone that passes vibrations from the stirrup to the cochlea. This is
the smallest bone in the human body (it is 0.25 to 0.33 cm long).
Volley Principle: A theory of frequency; we can achieve a combined frequency above 1000 times per second by
firing neural cells in rapid succession.
Label as many parts of the ear as you can without looking at the other diagrams.
(Tip: coloring the parts may help distinguish them more effectively for labeling
and studying purposes.
Previous diagram labeled
Guess That Sound!
Jiggling coins, clinking glasses, clapping hands...think you know what these sound like? The purpose
of this game is to test the ability of people to identify several sounds. People should close their eyes or turn
away from the "sound maker." Make each sound and see if everyone knows what it is. Example sounds:
1. Shake pennies or other coins
2. Clap hands
3. Clap chalkboard erasers
4. Tap a pencil or pen on a desk
5. Close a book
6. Crumple up paper or foil
7. Stomp on the floor
8. Tear some paper
9. Close a stapler
10. Bounce a ball
I am sure that you can think of more sounds to make. You could also have people take turns making
sounds and asking the others to guess the noise.
Materials:

Items to create sounds with (see examples above or create your own).
In the Middle!
Let's get a little more scientific here (hear?). Blindfold one person and have him sit in the middle of
the class. Have the other people form a large circle around the blindfolded person. Point to one of the
people in the circle and have him say the seated person's name. The seated person must then try point in
the direction of the voice and identify the name of the person who said his name. Try this experiment with
the seated person using both ears and then again with one ear closed. How accurate can the center person
identify the caller and where the call came from? Are two ears better than one?
Materials:

Chair for center subject

Blindfold
This game will demonstrate the ability to locate
by which ear the sound waves hit first, and the
intensity which the make contact with the ear.
Auditory Acuity
You hear the ringing of the phone in the middle of the night, but you just can't find it. You can hear
it, but you can't see it. Where is that thing? Just how good is the ability to find things using only the sense of
hearing? Blindfold a person. Have him cover one ear. Take a watch or stopwatch that "ticks". An electric
watch will not work. Ask the student to tell you when he hears some "ticking". Approach the blindfolded
person from several different angles and record the distance when the subject says "I can hear the ticking".
Keep track of the angles and the distances. Repeat the same experiment with the student's other ear
closed. Then do it again with both of his ears opened.
Questions and Comparisons:
1. The distances for the different ears.
2. Both ears vs. one ear.
3. The best and worst angles for detection.
4. Your ear's performance vs. your partner's ear's performance.
Materials:
Two Ears are better than one: Sound Localization
To show the importance of two ears, try this one. Make an X on the floor with tape or chalk or
erasable marker. Measure distances in a straight line in increments of 5 ft (1.5 m) from the X and label
each of these points with the distance it is from the X (5 ft, 10 ft, 15 ft, etc.) Now for the test. Place a
blindfolded subject on the X. Now, you stand on one of the points away from the X. Say the subject's name.
The subject must now tell you which line you are standing on. Try it when the subject uses one and both
ears. Make it harder with shorter distances from the X. Are 2 ears better than one in judging distance?
Materials:

tape OR chalk OR marker
For most people, it will be easier to judge distance using two ears. Our brains use the loudness of
sounds and the differences in time for sounds to reach each ear to make accurate determinations of
sound locations.
Hearing Quiz
1. What is the measuring unit for sound energy?
A. Frequency
C. Audition
B. Decibels
D. Liters
2. Place theory is associated with which membrane?
A. Cochlea’s
C. Cell
B. Hearing
D. Sensory
3. True or False: Hearing loss caused by damage to the mechanical system is sensorineural hearing
loss?
A. True
B. False
4. Long waves have _________ frequency and _______ pitch.
A. High, low
C. Low, low
B. Middle, middle
D. Low, high
5. The middle ear contains which three tiny bones?
A. Hammer, anvil, stirrup
C. Tibia, femur, anvil
B. Fore bone, middle bone, outer bone D. None of the above
6. Audition is _________.
A. A tone’s highness or lowness.
C. Projection of actions and voice.
B. The rate nerve impulses that travel D. What links pitch and area.
up the auditory nerve.
7. What is used to restore hearing for people with nerve deafness?
A. Headphones
C. Hearing transplant
B. Nothing
D. Cochlear implant
8. The National Center for Health Statistics estimates that ______ percent of people are born deaf.
A. 25%
C. 17%
B. 7%
D. 1%
9. Individuals cannot fire neurons faster than 1000 times/ second.
A. True
B. False
Select 2 to discuss
10. Discuss the volley principle and explain how it works.
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
11. Explain the reasoning/ rational behind Helen Keller’s statement that she “found deafness to be a
much greater handicap than blindness… Blindness cuts people off from things. Deafness cuts
people off from people”.
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
12. Why do older people suffer hearing loss of high frequencies?
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
Hearing Quiz Key
13. What is the measuring unit for sound energy?
C. Frequency
C. Audition
D. Decibels
D. Liters
14. Place theory is associated with which membrane?
C. Cochlea’s
C. Cell
D. Hearing
D. Sensory
15. True or False: Hearing loss caused by damage to the mechanical system is sensorineural hearing
loss?
B. True
B. False
16. Long waves have _________ frequency and _______ pitch.
C. High, low
C. Low, low
D. Middle, middle
D. Low, high
17. The middle ear contains which three tiny bones?
C. Hammer, anvil, stirrup
C. Tibia, femur, anvil
D. Fore bone, middle bone, outer bone D. None of the above
18. Audition is _________.
C. A tone’s highness or lowness. C. Projection of actions and voice.
D. The rate nerve impulses that travel D. What links pitch and area.
up the auditory nerve.
19. What is used to restore hearing for people with nerve deafness?
C. Headphones
C. Hearing transplant
D. Nothing
D. Cochlear implant
20. The National Center for Health Statistics estimates that ______ percent of people are born deaf.
C. 25%
C. 17%
D. 7%
D. 1%
21. Individuals cannot fire neurons faster than 1000 times/ second.
B. True
B. False
22. Discuss the volley principle and explain how it works.
The volley principle is like soldiers who alternate firing so that some can shoot while others reload, aq
group of neural cells that can alternate firing. By firing in rapid succession, they can achieve a
combined frequency above 1000 times per second.
23. Explain the reasoning/ rational behind Helen Keller’s statement that she “found deafness to be a
much greater handicap than blindness… Blindness cuts people off from things. Deafness cuts
people off from people”.
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
24. Why do older people suffer hearing loss of high frequencies?
People suffer hearing loss for high frequencies because of nerve degeneration near the beginning of
the basilar membrane.