Slide presentation by Margaret Johnson to Samford students on the importance of protecting your hearing.

1. The ear, the pathway to
sound, and the protection
of hearing
Samford University
Music Department
Margaret L. Johnson
February, 2014

2. What is Sound?
• ... a sound is any disturbance of air
that could cause a displacement of
the eardrum which, after
transmission by the bone chain,
could affect the liquid in the inner
ear in such a way that the auditory
nerves are stimulated.”
– “Ladefoged, Elements of Acoustic Phonetics, pp. 2-3”

3. How sound travels
• “The source of sound causes
movements of the air particles in its
immediate neighborhood; these
movements cause disturbances in the
air a little farther away from the
source; these air particles in their
turn affect their neighbors which are
still farther away from the source;
and so the disturbance spreads
outward.”

4. Just another sound: the human
voice
• voice: fluctuations of air pressure > caused by
rapid opening and closing of vocal folds
• pressure rises to a maximum, then falls
steadily to a minimum before rising again to
repeat the cycle, all within a small fraction of a
second

5. The Path of Sound
• external canal
• vibrates eardrum
• vibration moves through
ossicles
– mallet (malleus), anvil
(incus), stirrup (stapes)
• stapes vibrates oval
window of cochlea
• creates pressure wave in
the fluid inside

6. The Ear
• outer ear
– protection
– transmission of sound
• middle ear
– transformation into and
transmission of mechanic
vibrations
• inner ear
– transformation of vibrations
into neural impulses

7. The Outer Ear
• Pinna / auricle
– protects the entrance to the ear canal
– contributes to our ability to locate
sounds, esp. at higher frequencies
• Meatus/outer ear canal
– pathway for the acoustic signal
– protection of the inner ear
– tube resonator, i.e. favors transmission
of high-frequency sounds (2000-4000
Hz) and generally between 500 and
4000 Hz

8. The Middle Ear
• the ossicles pick up the
mechanical movement of the
eardrum and convey it to the
inner ear/oval window
• transformation of air pressure
variation into equivalent
mechanical movements
• contraction between anvil and
stirrup can reduce amplitude
(protection for inner ear)

9. The Middle Ear Cont‘d
• Eustachian tube:
– narrow tube connecting pharynx
and middle ear
– equalizes air pressure differences
between outer and middle ear
– Oval window:
– interface between middle and
inner ear
– transmits mechanical movement

10. Damage to the middle ear
• Loud impulse noises can perforate the
eardrum, dislodge the 3 tiny bones in the
ear
• This can cause what we know as a
conductive hearing loss; with some cases,
the hearing loss can be repaired

11. The Inner Ear
• cochlea
– coil-like structure terminating
in a window with a flexible
membrane at each end
– internally divided by two
membranes, filled with
cochlear fluid
– converts mechanical
movements into neural signals

12. The Inner Ear Cont‘d
• Organ of Corti:
– attached along the basilar
membrane
– hair cells which get moved
and excited
– responsible to transform
membrane displacement into
neural signals
– 1. inner hair cells
– 2. outer hair cells
– 3. tunnel of Corti
– 4. basilar membrane

13. The Inner Ear Cont‘d -Hair Cells
• ~16,000 in each cochlea
– located on the basilar membrane
– do not regenerate
– inner (~ 3,500) hair cells vs.
outer hair cells (~
20,000)
– stimulated by bending of the
basilar membrane (length of
wave on the basilar membrane
depends on frequency of sound
– amplitude
• lower & medium
amplitudes affect outer hair
cells,
• higher amplitudes affect
inner hair cells

14. Damage to the Inner Ear
• When excessively loud noises enter the inner ear, permanent
sensorineural hearing loss can occur
• A sensorineural loss is one where the ability to transmit sound
to the brain in order for the sound to be understood is damaged
in some manner
• Severity of the hearing loss depends on how many of the hair
cells in the inner ear are damaged
• These hair cells do not regenerate and cannot be repaired.

15. The Auditory Nerve
• Auditory nerve:
– picks up the neural signals from the organ
of Corti
– sends signals to the brain where the
information is processed and interpreted

16. Noise Exposure
• Any kind of sound is
known as “noise”
• Prolonged exposure
to any sound/noise
over 85 dB can cause
irreversible hearing
loss
• 30 dB = whisper
• 50 dB – moderate rain
• 60 dB = average
conversation
• 70 dB = freeway traffic
• 80 dB = Alarm Clock (bells)
• 90 dB = Blender, blow dryer,
a subway
• 100 dB = MP3 players at full
volume; lawnmowers
• 110 dB = Rock concerts,
sporting events, power tools
• 120 dB = jet planes taking
off
• 130 dB = sirens, race cars,
jackhammers
• 140 dB = guns, fireworks

17. What do we know?
• Acute hearing and perception are essential for
all musicians
• Noise induced hearing loss is preventable
• Musicians have a personal responsibility to
protect their hearing
• Sound level management is critical

18. What are the variables?
• Sound level variation
• Performance and rehearsal settings
• Distance from sound
• Length of exposure

19. Solo vs. Ensemble(s)
• Obviously, the solo performer has the
advantage over ensemble
• Ensemble practice (whether vocally or
instrumentally) can average greater than
the preferred 85dB.
• The key to solving this problem is
measurement of sound

20. Sound level measurement
• Sound level meters
• Dosimeters
• Range in price from $20.00 to $2000

21. Ear Protection
• Earplugs
• Earmuffs
• Acoustical sound shields
• All of these can be made specifically for
musicians

22. How do I protect myself?
• Avoid noisy/loud situations for prolonged periods of time
• Stay away from noisy activities unless you are well protected
• Maintain your distance from noise
• When using in the ear earphones, make sure that the levels
are safe
• Attend to your noise exposure throughout the day
• Take a break from noisy environments

23. Vocal Health for musicians
Samford University
February, 2014

24. The vocal tract
• Larynx – where the vocal
folds are located
• Pharynx – 3 portions
– Laryngopharynx
– Oropharynx
– Nasopharynx
• Trachea – pathway to lungs
• Spinal Column – support
• Diaphragm – respiratory
support

25. Vocal folds vs. cords
• Folds is the more appropriate term
• Vocal cords came from the thinking that these
layers of tissue were stretched across the
trachea, like strings on a piano
• Now we know that these are multilayered
folds of tissue that are continuous with other
tissues in the pharyngeal cavity

26. Terms to be aware of
• Phonation – the act of voicing
• Dysphonia – poor vocal quality; “breathy,
hoarse, raspy”
• Mucosa – the tissue that lines the entire
inside of our oral and pharyngeal cavity. It is
soft and wet, and prefers to stay that way

27. Abduction & adduction
• Abduction – movement away from the center
– the folds are abducted when we are
breathing and not talking
• Adduction – movement toward the center –
the folds are adducted when they are together
and are creating voice; even when we whisper,
our vocal folds are adducting

28. Vocal fold vibration and pitch
Slow vibratory
pattern
Rapid vibratory
pattern
494
The term for vibration, or cycles, per second is Hertz (Hz)

29. Men vs. women in pitch and cycles
per second
• Men = average of 115
Hz per second
• Women = average of
200 Hz per second
• Sopranos = 246.9 Hz
• Mezzo-Soprano = 196
Hz
• Contralto = 174.6 Hz
• Tenor = 164.8 Hz
• Baritone = 123.5 Hz
• Bass = 98.0 Hz

30. Causes of vocal injury or illness
The following list is not inclusive of all things that can cause vocal issues,
but rather a general list of “frequent offenders”
• Vocal abuse: (can result in nodules, polyps, hemorrhaging, general
irritation and laryngitis)
– Yelling, screaming, hollering (especially cheerleading– a common source of
adolescent vocal problems)
– Forceful singing; extended singing
– Throat clearing and coughing
– Loud talking (especially in loud settings like sporting events, restaurants, parties, etc.)
– Whispering! This can put great strain on the larynx

31. Causes of vocal injury/illness
• Vocal overuse (can have the same effects as
vocal abuse by the general “wear and tear” of
the vocal folds)
– Singing for too long (this can especially occur
during long rehearsals like choral festivals)
– Talking for too long (cell phones - especially while
in the car, reunions, visiting with friends late at
night, etc…) ** low-pitched talking can be
especially detrimental

32. Nodules
• Nodules (also called “nodes”): A common injury that
is essentially a small growth found on one or more
commonly, both of the folds (nodules are much like a
callus on the hand or foot); Nodules keep the folds
from fully closing, resulting in a harsh/breathy voice

33. Polyps
• Polyps are like nodules in that they are also a growth on the folds
that keep the folds from closing, but are more like a soft lesion
than a hard callus
• Polyps may be on either just one fold or both (typically on just
one side); both abusive phonation and smoking are common
reasons for polyps

34. Hemorrhage
• A hemorrhage is where a blood vessel
“explodes” due to excessive pressure; (think
extended overuse)

35. Laryngitis
• Laryngitis is the inflammation of the vocal folds
• It may be the result of reactions to allergies, bacterial or fungal
infections, or the result of vocal overuse
• With laryngitis, the vocal folds often swell too much to correctly
close, resulting in the lack of phonation (dysphonia)

36. Treatment
• For treatment of nodules, polyps, laryngitis, hemorrhaging: A
DOCTOR should be consulted!
• In general, total vocal rest (NO talking, singing or whispering for
an extended period) is the first line of defense, and in some cases,
can help cure some of the above conditions; increased hydration
may also be beneficial; in general, resting the voice is important
whenever it feels strained or if the sound is not normal
• Surgery may be required in some cases

37. Acid Reflux as irritant
• Reflux (backflow of stomach acid) can cause significant irritation,
burning or swelling on vocal folds/larynx; Two types:
– “GERD”: Gastroesophageal reflux disorder– is when acid backflows into
esophagus (food pipe)
• Symptoms: Heartburn, regurgitation; occurs while laying down
– “LPR”: Laryngopharyngeal reflux– is when acid backflows into
larynx/pharynx
• Symptoms: Too much mucous in throat, need to clear throat often, sour taste
in mouth, hoarse voice, feeling of a “lump” in the throat

38. More on Reflux
• Reflux is best treated by a gastroenterologist; The GI may also
refer you to an ENT
• Preventing reflux from occurring is the best medicine; the
following can help to do so:
– Diet: avoid very spicy foods, alcohol/caffeine (both rob
body of moisture), highly acidic foods (citrus fruits and
tomatoes), carbonated drinks, chocolate, dairy products,
fatty foods
– Eat at least 3 hours prior to going to bed
– Exercise/lose weight (if overweight)

39. Keys to vocal health
• The larynx is very much a finely tuned musical instrument
and should be taken care of like a fine violin (plus, the
vocal folds can NEVER be replaced!)
• Hydration is key! Water is the best fluid for the body. Try
to drink at least 64 oz. a day (about ½ gallon)
the vocal cords need
constant lubrication while
singing

40. More on hydration…
• The body should produce about 1 liter of
mucous a day! However, it needs lots of
water to do so; in order to keep the mucous
“thin”, much water is needed
• Foods like grapes, melons, cucumbers have a
lot of water and are quite beneficial
• Alcohol, caffeine, smoking and
antihistamines all dry the body/vocal folds
• A humidifier in dry areas or your bedroom
may also be beneficial

41. Vocal health
• Try not to sing forcefully or for long periods of
time; let your choral director know if you are
experiencing vocal fatigue
• Try to avoid singing hard glottal attacks (where
the voice is initiated quickly with force– as on
words like “Go”); this can be helped by
beginning the breath/airflow before the pitch is
phonated– especially on vowels

42. Vocal health
• Warm up! The larynx should get increased blood flow and
stretching before singing; it is also a good idea to cool down
gently after long/taxing rehearsals
• Light, downward glides are some of best “first” warm up
exercises (go from stretched cords to relaxed)
• Lip buzz/lip trills
• There are 3 groups of muscles that are involved:
– (1) Breathing muscles
– (2) Phonation muscles
– (3) Pitch Change Muscles

43. Bodily Health:
Exercise is key component!
• Exercise: Frequent exercise can
help promote a strong circulatory
system, efficient lungs and good
immunity toward sickness
• Try to get 8 hours of sleep!
• Don’t grunt when lifting weights!
It creates dramatic pressure
against the folds

44. Vocal health cont’d…
• When talking on the phone, hold
the phone with your hand, not with your shoulder as the
position can put a lot of strain on the larynx and neck
muscles
• The singing voice should last for hours without much
discomfort; if hoarseness, discomfort or lack of
range/phonation occur, it is an indication of a problem with
the voice, or an issue with singing technique

45. More on vocal health…
• Smoking can cause dramatic changes to
the tissues in and around the vocal folds
and is the primary cause of laryngeal
cancer;
• It robs the vocal folds of full flexibility
because of it’s drying effects. Singers
should not be smokers.

46. Summary
• The voice is a wonderful instrument; man has made
nothing like it! Singing is a great privilege and the
vocal folds should be treated with care and
protection
• The tips in this presentation can help you maintain
your voice for years to come, but in the event of any
vocal problem, the advice of a doctor/laryngologist is
the most important action you can take