question: Why does a cold cause your voice to get deeper?
comment: Swelling of the vocal folds makes them heavier and that causes them to vibrate at lower (deeper) frequencies. If you look at a guitar or any string instrument you will notice the thicker strings are the lower notes.
passages: BULLET::::- "air humidity" - dry air is thought to increase the stress experienced in the vocal folds, however, this has not been proven
  
  BULLET::::- "hydration" - dehydration may increase effects of stress inflicted on the vocal folds
  
  BULLET::::- "background noise" - people tend to speak louder when background noise is present, even when it isn't necessary. Increasing speaking volume increases stress inflicted on the vocal folds
  
  BULLET::::- "pitch" - Using a higher or lower pitch than normal will also increase laryngeal stress.
   Section::::Clinical significance.:Reinke’s edema.
  
  A voice pathology called Reinke’s edema, swelling due to abnormal accumulation of fluid, occurs in the superficial lamina propria or Reinke’s space. This causes the vocal fold mucosa to appear floppy with excessive movement of the cover that has been described as looking like a loose sock. The greater mass of the vocal folds due to increased fluid lowers the fundamental frequency ("f") during phonation.
  
  Section::::Clinical significance.:Wound healing.
   BULLET::::- "voice quality" - Using a vocal quality which differs from that habitually used is thought to increase laryngeal stress.
  
  In addition, smoking and other types of air pollution might have a negative effect on voice production organs.
  
  Section::::Symptoms.
   Signs that consolidation may have occurred include:
  
  BULLET::::- Expansion of the thorax on inspiration is reduced on the affected side
  
  BULLET::::- Vocal fremitus is increased on the affected side
  
  BULLET::::- Percussion is dull in the affected area
  
  BULLET::::- Breath sounds are bronchial
  
  BULLET::::- Possible medium, late, or pan-inspiratory crackles
  
  BULLET::::- Vocal resonance is increased. Here, the patient's voice (or whisper, as in whispered pectoriloquy) can be heard more clearly when there is consolidation, as opposed to the healthy lung where speech sounds muffled.
  
  BULLET::::- A pleural rub may be present.
   Section::::Notes.
  
  BULLET::::- Burgess Meredith later in 1968 portrayed the character of Elvis Presley's father Charlie Lightcloud in the MGM comedy film "Stay Away, Joe".
  
  BULLET::::- Burgess Meredith and Cesar Romero were the most frequent "guest villains" as The Penguin and The Joker, respectively. In fact, whenever Meredith was in town the producers had a script waiting for him. He had given up smoking for years when he was cast in the role of The Penguin. The squawk in his voice came from the way the cigarette smoke affected his lungs and throat.
   The facial bones begin to grow as well. Cavities in the sinuses, the nose, and the back of the throat grow bigger, thus creating more space within the head to allow the voice to resonate. Occasionally, voice change is accompanied by unsteadiness of vocalization in the early stages of untrained voices. Due to the significant drop in pitch to the vocal range, people may unintentionally speak in head voice or even strain their voices using pitches which were previously chest voice, the lowest part of the modal voice register.
  
  Section::::History.
   Vocal fold cysts cause the properties of the vocal folds to change. When a cyst is present on a vocal fold, the cover of the vocal fold becomes more stiff and increases in mass. The increased mass and stiffness tends to result in hyperkinetic muscular movement during phonation. Hyperkinetic movement is characterized by increased rigidity in the affected vocal fold(s). This hyperkinetic movement results in the voice being perceived as hoarse. (see Signs and Symptoms) Specifically, the presence of a vocal fold cyst leads to an asynchronous mucosal wave of the vocal folds during phonation.
  
  Section::::Causes.
   Secondly, an increase in the hoarseness and strain of a voice can often be heard. Unfortunately, both properties are difficult to measure objectively, and only perceptual evaluations can be performed.
  
  Section::::Voice care.
   BULLET::::- "sac-like" appearance of the vocal folds
  
  BULLET::::- Hoarseness and deepening of the voice
  
  BULLET::::- Trouble speaking (Dysphonia)
  
  BULLET::::- Reduced vocal range with diminished upper limits
  
  BULLET::::- Stretching of the mucosa (Distension)
  
  BULLET::::- Shortness of breath (Dyspnoea)
   A key aspect of preventing vocal fold cysts is good vocal hygiene. Good vocal hygiene promotes the healthy use of the vocal apparatus and the avoidance of phonotrauma. Good vocal hygiene practices involve the avoidance of:
  
  BULLET::::- Shouting
  
  BULLET::::- Whispering loudly or for long periods of time
  
  BULLET::::- Large quantities of talking over loud background noise
  
  BULLET::::- Talking while yawning
  
  BULLET::::- Continual clearing of the throat
  
  BULLET::::- Speaking in an unnatural voice (i.e. too high or low)
  
  BULLET::::- Talking with a cold or laryngitis
  
  BULLET::::- Smoking tobacco or marijuana
  
  BULLET::::- The consumption of alcohol and coffee
   Normally, the sound of the patient's voice becomes less distinct as the auscultation moves peripherally; bronchophony is the phenomenon of the patient's voice remaining loud at the periphery of the lungs or sounding louder than usual over a distinct area of consolidation, such as in pneumonia. This is a valuable tool in physical diagnosis used by medical personnel when auscultating the chest.
   Staying hydrated decreases the pressure that the vocal folds exert on one another by ensuring sufficient lubrication by mucosa, increasing the efficiency of vocal fold oscillation during speech, and promoting a healthy voice quality. Consumption of caffeine in large quantities is dehydrating and is therefore implicated in an increased risk of vocal fold nodules.
  
  Section::::Prevention.:Lifestyle changes.
   Section::::Profile.
  
  The profile begins with Sinatra in a sullen mood at a private Hollywood club. Stressed about all the events in his life, Sinatra, and many of his staff, are in a poor mood because Sinatra is afflicted by the common cold, hampering his ability to sing. The significance of the cold is expressed by Talese in one of the story's most famous passages:
   BULLET::::- great lung volumes are used,
  
  BULLET::::- it is accompanied by larger facial movements, though these do not aid as much as sound changes
  
  These changes cannot be controlled by instructing a person to speak as they would in silence, though people can learn control with feedback.
  
  The Lombard effect also occurs following laryngectomy when people following speech therapy talk with esophageal speech.
  
  Section::::Mechanisms.
   Vocal loading
  
  Vocal loading is the stress inflicted on the speech organs when speaking for long periods.
  
  Section::::Background.
  
  Of the working population, about 13% have professions where their voice is their primary tool. That includes professions such as teachers, sales personnel, actors and singers, and TV and radio reporters. Many of them, especially teachers, suffer from voice-related medical problems. In a larger scope, this involves millions of sick-leave days every year, for example, both in the US and the European Union. Still, research in vocal loading has often been treated as a minor subject.
  
  Section::::Voice organ.
   Section::::Physiological process.
  
  In the modal register, the length, the tension, and the mass of the vocal folds are in a state of flux which causes the frequency of vibration of the vocal folds to vary. As pitch rises, the vocal folds increase in length and in tension, and their edges become thinner. If a speaker or singer holds any of the three factors constant and interferes with the progressive state of change, the laryngeal function of the voice becomes static and eventually breaks occur resulting in obvious changes in vocal quality.
   Section::::Themes.
  
  In his never-to-be-finished 1885 novel "Sława" (Fame), Prus excoriates his countrymen:
   Section::::Production.
   For individuals who work with their voice (e.g., singers, actors, teachers, stock brokers) voice training that includes vocal function exercises (VFEs) may help to reduce undue vocal strain. Furthermore, recommendations for voice professionals include warm-up and cool-down exercises for the voice to reduce strain. Additionally, using amplification devices, such as speakers or microphones, is recommended for individuals who speak to large, and even small groups or in the presence of background noise.
  
  Section::::Prevention.:Hydration.
   BULLET::::- Vocal abuse: Vocal abuse is the misuse or overuse of the voice in an unhealthy fashion such as clearing the throat, yelling, screaming, talking loudly, or singing incorrectly.
  
  BULLET::::- Clearing the throat: Clearing the throat removes or loosens phlegm but the vocal cords hit together causing inflammation and therefore more phlegm.
  
  BULLET::::- Yelling/screaming: Yelling and screaming both cause the vocal cords to hit against each other causing inflammation and phlegm.
  
  BULLET::::- Nodules: Excessive yelling, screaming, and incorrect singing as well as other vocal abusive habits can cause vocal nodules. See vocal fold nodule for more information on nodules.
   BULLET::::- The use of antihistamines, aspirin, steroids, tricyclic antidepressants, or any substance that alters perception (i.e. sleeping pills)
  
  BULLET::::- Foul air
  
  In addition, good vocal hygiene involves getting enough rest and drinking lots of water. It is important to keep the vocal fold tissue healthy and hydrated, and when possible to limit the quantity of speaking in order to avoid damage.
  
  Section::::Treatment.
   Section::::Signs and symptoms.:Aerodynamic signs.
  
  If the nodules affect the closure of the vocal folds, airflow levels during speech may be increased in comparison to the speaker's habitual levels. However, airflow levels may still fall within the upper limits of the normal range. The degree to which an individual's airflow levels increase seems to depend on the severity of the injury. Subglottal pressure, the air pressure that is available below the glottis and in the trachea to produce speech, may be increased as well.
  
  Section::::Causes.
   Laryngitis can be infectious as well as noninfectious in origin. The resulting inflammation of the vocal folds results in a distortion of the sound produced there. It normally develops in response to either an infection, trauma to the vocal folds, or allergies. Chronic laryngitis may also be caused by more severe problems, such as nerve damage, sores, polyps, or hard and thick lumps (nodules) on the vocal cords.
  
  Section::::Causes.:Acute.
  
  Section::::Causes.:Acute.:Viral.
   At the beginning, patients hear their own voice or its echo from inside. They describe it as being amplified and unpleasant. Patients frequently avoid speaking and retire in a rising solitude. Lying head down may help since it increases venous blood pressure and congestion of the mucosa.
  
  Section::::Causes.
   Aside from a hoarse-sounding voice, changes to pitch and volume may occur with laryngitis. Speakers may experience a lower or higher pitch than normal, depending on whether their vocal folds are swollen or stiff. They may also have breathier voices, as more air flows through the space between the vocal folds (the glottis), quieter volume and a reduced range.
  
  Section::::Causes.
  