Download A.1.3.1StudentResourceSheet

Activity 1.3.1 Student Resource Sheet
Part I: The Physics of Sound
Sound, like electricity and light, is a form of energy that travels in waves. When a
pebble is thrown into a pond, you will notice that the waves of water ripple out from
the center. Think of sound waves as these ripples of water. Sound is generated by
vibrations. The vibrations act as the pebble and push the molecules of air around
them outward. These molecules then bump into their neighboring molecules,
creating waves.
Every sound has two main characteristics, pitch and intensity. Pitch is determined by
a sound’s frequency, or how rapidly the sound waves vibrate each second.
Frequency is measured in vibrations per second, or Hertz (Hz). The higher the
frequency of the sound, the more frequently the waves vibrate, and the higher the
sound’s pitch is. Sound intensity is determined by a sound’s amplitude, or the
amount of energy in the wave. The more energy the sound wave has, the higher the
amplitude, and the louder the sound seems. Sound intensity is commonly referred to
as loudness.
Sound intensity is measured as decibels (dB). The decibel scale begins at 0 dB,
which is the intensity of the sound that is least perceptible by a normal human ear.
Because the range of intensity that a human ear can register is so large, the decibel
scale is a logarithmic scale. For example, a sound of 20 decibels is one hundred
times louder than 0 decibels; a sound of 30 decibels is one thousand times louder
than 0 decibels. A whisper has an intensity of around 40 dB; whereas, the music at a
rock concert has an intensity around 140 dB. Frequent or prolonged exposure to
sounds with intensities above 85 dB can damage hearing receptors and cause
permanent hearing loss.
Part II: Hearing Loss Case Studies
Patient One:
Patient One is a 45-year-old machine operator at a local factory. Lately, he has been
complaining of a constant ringing in his ears and has noticed that he has a difficult
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Medical Interventions Activity 1.3.1 Student Resource Sheet – 1
time following conversation. His wife convinced him to get his hearing tested, and an
audiologist found that he has noise-induced hearing loss with moderate to severe
sensorineural hearing loss in both ears at frequencies around 4000 Hz and mild
sensorineural hearing loss in both ears at frequencies around 8000 Hz. The hearing
loss is accompanied by tinnitus.
Patient Two:
Patient Two is a six-year-old male. He has been experiencing chronic middle ear
infections (also known as chronic otitis media) since he was six months old.
Because he has a very narrow, short Eustachian tube in his right ear, he is
susceptible to bacterial infections. He has had ear tube surgery twice, where a small
tube was placed in the eardrum to ventilate the area behind the eardrum, keep the
pressure equalized and reduce infection. This surgery had little success. The last
two ear infections resulted in a perforated eardrum with a pus-like drainage from his
ear. Lately, his teacher informed his parents that his performance in school has
declined, and suggested he be tested for hearing loss. An audiologist found that he
has mild to moderate conductive hearing loss in his right ear.
Patient Three:
Patient Three is a 24-year-old female who was born with a cochlear abnormality in
her left ear. This abnormality causes her to experience a difficult time understanding
lower-pitch noises; often she has difficulty following conversation in a crowded room.
She has been diagnosed with moderate low-to-mid frequency sensorineural hearing
loss in her left ear.
Patient Four (Sue Smith):
Patient Four is an 18-year-old college freshman who just recovered from a bacterial
meningitis infection. She has not noticed any difficulties hearing, but was referred to
an audiologist by her primary care physician. An audiologist found that she has mild
low frequency sensorineural hearing loss in both ears.
Patient Five:
Patient Five is a 71-year-old female. She began noticing that she had a difficult time
understanding and hearing speech when she was in her early sixties. Lately, the
condition has gotten worse. Hearing tests confirmed that she has presbycusis, a
hearing loss caused by the natural aging of the human body, and as a result has
severe mid-to-high frequency sensorineural hearing loss in both ears.
Patient Six:
Patient Six is a 44-year-old female. She was recently diagnosed with Meniere’s
Disease, an abnormality of the inner ear associated with a change in fluid volume
within the labyrinth. She constantly experiences episodes of severe vertigo (a feeling
of spinning), imbalance, nausea, and severe low frequency sensorineural hearing
loss in both ears. Sometimes the episodes are infrequent and other times occur
more frequently.
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Medical Interventions Activity 1.3.1 Student Resource Sheet – 2
Patient Seven:
Patient Seven is a 38-year-female rock star who just finished her twentieth
international tour. Lately, she has noticed that she has trouble distinguishing
between certain sounds and has a difficult time hearing the higher voices of women
and children. An audiologist has confirmed that she has moderate high frequency
sensorineural hearing loss in her left ear.
Patient Eight:
Patient Eight is a 68-year-old male who recently was treated for an upper respiratory
viral infection which caused inflammation of the labyrinth, the part of the inner ear
that helps control balance (a condition called labyrinthitis). This condition has caused
vertigo, a feeling of dizziness and spinning, as well as a moderate sensorineural loss
in his left ear at low frequencies and a mild sensorineural hearing loss in his left ear
at medium frequencies. The audiologist also confirmed a mild sensorineural hearing
loss in the patient’s right ear.
Patient Nine:
Patient Nine is a 21-year-old male staff sergeant who just finished a tour of duty
overseas. Since he has been back, he has experienced a constant buzzing sound in
his left ear. Hearing tests show a mild sensorineural hearing loss in his left ear with
Tinnitus.
Patient Ten:
Patient Ten is a 24-year-old female. She has otosclerosis, an inherited disorder in
which an abnormal sponge-like bone grows in the middle ear. Her mother also had
otosclerosis and became deaf by the time she was 45. Both of Patient Ten’s ears
have been affected by the disorder and an audiologist confirmed that she has
progressive mild to moderate conductive hearing loss in both ears.
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Medical Interventions Activity 1.3.1 Student Resource Sheet – 3