How Voice is Made

How Voice is Made

Image credits

Phonationand Speech

Muscular Involvement

Vocal Folds

Exhalation

Inhalation

Respiration

The cycle of breathing in and out

Breath support is crucial for voice production

• Good posture (sitting upright with feet straight on the floor) sets up effective respiration
• As an individual inhales through their nose or mouth, the diaphragm moves down and contracts
• The phrenic nerve allows the diaphragm to work
• Spinal nerves are also important for breathing
• The chest expands and the lungs are filled with air
• Muscles in the ribs (external intercostals) are also activated when inhaling
• Passive breathing (or breathing normally) requires little effort
• Breathing for speech requires more effort and more muscles are involved

Image from: https://ramseyvoice.com/

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Respiration

The cycle of breathing in and out

How can respiration be negatively impacted?

• Poor posture can limit the capacity of the lungs
• Damage to muscles of the neck, back, upper arm and shoulder that are involved in exhalation could cause difficulties with respiration
• Damage to the phrenic nerve or other spinal nerves could impact one's ability to breathe effectively

Learn more about the process of respiration by watching this video.

Image from: https://www.sciencedirect.com/science/article/pii/S2468867319300835

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Exhalation

How does exhalation impact voice production?

• Quiet breathing (passive respiration) when not producing voice uses gravity and recoil to exhale air
• Exhaling to produce voice requires a longer, steadier exhale
• As an individual forcefully exhales air to produce voice, many muscles are involved
• Muscles of the upper limb, thorax, back, and abdomen are all involved in controlled exhalation
• The air is exhaled at a constant flow and goes up to the glottis where the vocal folds are located in the larynx
• Effort is needed during this process of respiration when exhaling air for speech, but not to produce voice
• Do you feel effort when producing voice? You may have a voice disorder.

Image from: https://en.wikibooks.org/

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The Vocal Folds

The vibration of the vocal folds and voice

In this image, the arrow represents the flow of air that goes through the vocal folds as they open and close.

• The vocal folds are closed as air moves up through the trachea to the larynx
• The movement of air pressure causes the vocal folds to open
• After the vocal folds open, lower pressure is created behind the fast moving air particles
• This is called The Bernoulli Effect
• The vocal folds close and begin to vibrate
• Vibration continues until there is complete closure of the vocal folds, which cuts off the flow of air
• A new cycle begins with the first step

Image from: voicefoundation.org

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The Vocal Folds

What happens if there is damage to the vocal folds?

• Overuse or misuse of one's voice may damage their vocal folds, which will change voice production
• Nodules, ulcers, or sores may appear on the vocal folds (the white lines in pictures to the right)
• Specifically, the 2nd layer of the vocal folds can become stiff due to nodules or tumors
• This layer is also called Reinke's space, and fluid can accumulate here (particularly in smokers), which could affect the production of one's voice

Images from: https://www.howitworksdaily.com/

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Muscular Involvement

What muscles are involved in producing voice?

• Muscles must work together to coordinate effective voice production
• Muscles connected to the hyoid bone (located above the larynx) can raise and lower the larynx, which in turn changes the length of the vocal folds and the pitch of the speaker
• The cricothyroid muscle is very important for raising pitch
• Various muscles are important to close and open the vocal folds
• Muscles that close the vocal folds: Lateral Cricoarytenoid, Transverse and Oblique Interarytenoid, Thyromuscularis
• Muscles that open the vocal folds: Posterior Cricoarytenoid
• Paired muscles should act together in a normal layrnx
• This allows for coordinated movements to occur from the muscles to produce voice

Image from: phillyent.com/anatomy

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Muscular Involvement

What happens if there is damage to these muscles?

• An individual may not be able to raise their pitch as much compared to their previous capabilities (e.g., damage to the cricothyroid muscle)
• An individual may be at risk for swallowing difficulties if they are unable to move the larynx up and forward efficiently (e.g., damage to suprahyoid muscles)
• If the vocal folds cannot vibrate together, this could affect one's voice
• For example, if an individual has one vocal fold paralyzed, this could result in difficulties when trying to bring the vocal folds together
• Damage to the muscles and structures involved in respiration can in turn affect one's voice quality

Image from: phillyent.com/anatomy

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Phonation and Speech Production

Producing Speech

• As air passes through the vibrating vocal folds, it is exhaled through the mouth during speech production
• Many factors determine the speech sounds that will be produced and how they will sound
• The place of the articulators (e.g., lips, tongue) in the mouth
• The voicing and freqency of the vocal folds (i.e., if they are vibrating or not and at what rate)
• The manner in which the sounds are produced (e.g., with two lips)
• Speech is then produced and an individual can communicate their message

Image from: http://www.learnlanguagesonyourown.com/

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Phonation and Speech Production

What if I have difficulties with producing speech?

• Many disorders and conditions exist that affect one's ability to produce speech effectively
• Some examples include aphasia, acquired apraxia of speech, and dysarthria
• You may have a voice disorder if you experience a variety of symptoms, including but not limited to those listed below
• abnormal pitch, loudness, resonance, or breathiness of your voice
• your voice may feel strained, strangled, or hoarse
• increased vocal effort when speaking

For more information on voice disorders, visit the link above or contact a speech-language pathologist for more information.

Image Credits

Lungs & Phonation and Speech Icon: FreePik Vocal Folds/Larynx & Muscle Icons: Smashicons