Voice Damage from Vocal Overload: Prevention and Essential Care
The voice is an essential work tool for many professions. Learn to identify risks, warning symptoms, and ways to prevent damage from vocal overload.
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The voice is the sound produced by the vibration of the vocal cords, located in the larynx, when air passes from the chest cavity. The larynx is composed of a set of cartilages, ligaments, and membranes that support the bands of muscular tissue called vocal cords. The tension, elasticity, height, width, length, and thickness of the vocal cords can vary, resulting in different sound effects.
The Phonation Apparatus
The phonation apparatus consists of the various organs involved in speech articulation, such as the larynx, oral cavity, lips, tongue, palate, jaw, and nasopharyngeal cavity. It is composed of three groups of differentiated organs:
- Respiratory organs: lungs, bronchi, and trachea.
- Phonation organs: larynx, vocal cords, and resonators (nasal, oral, and pharyngeal).
- Articulation organs: palate, tongue, teeth, lips, and glottis.
There are three phases in the origin of the voice:
- First phase: Generation of an airstream from the lungs that ascends through the bronchi and trachea. In this phase, the diaphragm, chest cavity, abdominal muscles, and back fundamentally act.
- Second phase: Occurs in the vocal cords. These must be closed, and the passage of air through them produces turbulence that transforms the air into sound.
- Third phase: The sound is sent through the throat, nose, and mouth.
The voice has different acoustic qualities:
- Timbre
- Intensity
- Pitch
- Duration
Timbre is the characteristic sound of each sound source and what allows us to distinguish a person by their voice.
Intensity is the power with which air passes through the larynx and vibrates the vocal cords. It is measured in decibels (dB) and varies between 30 and 120 dB. According to intensity, we can differentiate between low voice (less than 50 dB), conversational voice (between 50 and 65 dB), projected voice (between 65 and 80 dB), and shouting (between 90 and 110 dB).
Pitch is the elevation of the voice that results from the frequency of vocal cord vibrations. It allows the sound to be classified on a tonal frequency scale, from higher to lower.
Duration is the time used to emit sounds.
At-Risk Population and Vocal Demands
Anyone who, in the performance of their professional activity, uses their voice intensively, having it as a work tool, is at risk of vocal overload and of developing voice-related diseases. In teaching, the voice is the main work tool and cannot be replaced. There are also other professionals who depend on their voice, such as singers, actors, telemarketing operators, among others.
The professional use of the voice can be classified based on two characteristics that determine its performance in each job: its acoustic quality (the beauty of the voice) and its resistance capacity to fatigue. For example, for a teacher, acoustic quality is not as crucial as a high resistance to fatigue, while for a singer or actor, acoustic quality is predominant. Thus, each profession demands different properties from the voice.
Risk Factors
Environmental Factors
- Humidity level (dust, excessive dryness).
- Excessive cold or heat.
- Ventilation (drafts, air conditioning, poor ventilation).
- Exposure to irritants or other environmental contaminants (chemical, biological contamination, and mineral particles such as chalk, plaster, soil, etc.).
- Environmental noise.
- Acoustic quality of the place (sound conditioning of the place, poor acoustics).
Organizational Factors
- Work overload.
- Absence of breaks (after 2 hours of speaking or reading aloud, laryngeal signs of fatigue may appear. Breaks of 30 to 45 minutes are recommended).
- Lack of training in voice use and prevention of voice disorders.
Personal Factors
- Physical constitution and health (age, sex, physical constitution, dysphonia in childhood, vocal dysfunctions, pharyngitis, rhinitis, allergies, musculoskeletal anomalies of the cervical spine and shoulders, gastroesophageal reflux, endocrine disorders).
- Toxic habits (tobacco smoke, alcohol).
- Diet.
- Medication.
- Stress.
- Others (oral aerosols, lozenges, and substances derived from menthol and eucalyptus with a rebound effect).
Health Effects: Dysphonia and Aphonia
Health damage includes all situations where an acoustic modification of the voice is observed, causing an alteration of its basic qualities (timbre, pitch, and intensity). It can affect communication and prevent the normal development of daily activities. These changes are called dysphonia. The total absence of voice is called aphonia.
Dysphonia is classified as:
- Functional dysphonia: Alterations in voice qualities where only function is affected, with no identifiable lesion. They result from improper use of the voice and cease with the correction of organ use.
- Organic dysphonia: Arising from laryngeal alterations or an adjacent organ that alter the basic qualities of the voice. They can result from congenital alterations (malformations or membranes) or acquired ones (tumors, laryngitis, neurological diseases).
- Mixed dysphonia: Lesions resulting from incorrect and persistent use of the voice, causing changes in the microcellular structure of the vocal cords, which affect biomechanical characteristics. They can regress if vocal abuse is eliminated.
In people who use their voice as a work tool and present dysphonia that does not disappear with rest, it is crucial to rule out possible laryngeal lesions. The most known forms of presentation are nodules, polyps, and edema.
Nodules are a thickening of the vocal fold tissues. With continuous abuse of the vocal cords, their tissues can harden and transform into lesions called nodules. The longer the vocal abuse, the larger and harder the nodules become. They tend to appear on both vocal cords.
Polyps can have different shapes and appear on one or both vocal cords. They can resemble inflammation similar to a nodule or a blister-like lesion. Most polyps are larger than nodules and can also be referred to as Reinke's edema or polypoid degeneration.
Occupational diseases, such as vocal cord nodules, which result from the continuous use of the voice, for example in certain sectors of activity, must be properly prevented and monitored within the scope of occupational health.
Warning Symptoms
Regardless of the origin of the dysphonia, warning symptoms include:
- Hoarseness.
- Need to clear the throat or cough.
- Abundant secretions.
- Sensation of a foreign body in the throat or tingling.
- Sensation that the voice does not come out or that effort is needed to produce it.
- Lack of control of voice intensity or pitch.
- Pain and neck tension.
- Stinging in the anterior or lateral part of the neck.
- Rapid voice fatigue when speaking or voice weakness.
- Broken voice.
- Hoarse voice.
- Difficulty maintaining voice at the end of the day.
- Difficulty being understood.