Wong Seng Mun, Principal Speech Therapist from the Speech Therapy Department at Singapore General Hospital (SGH) shares four common factors that can cause a loss of voice.
When people say they’ve lost their voice, they usually mean that their voice has changed or doesn’t come out as easily. The voice may sound hoarse, lower or higher in pitch than usual, or even disappear on and off in a sentence.
"People who have lost their voice may experience strain and effort in producing and projecting the voice, or tightness in the throat," says Wong Seng Mun, Principal Speech Therapist from the
Speech Therapy Department at
Singapore General Hospital (SGH), a member of the
SingHealth group. Some may feel out of breath when talking. These symptoms may be short-lived, such as during a cold or flu, or may persist over a longer period.
As losing one’s voice can be quite annoying, let’s examine the most common factors that explain the phenomenon.
What could cause you to lose your voice
Lifestyle and vocal demand
On average, the vocal folds of an adult male vibrate about 120 times per second. Interestingly, this vibration frequency is roughly doubled in adult female speakers. Imagine how many cycles of vibration that represents, when you talk for hours at a stretch! Due to their professional, personal or recreational activities, some people place a heavy strain on their vocal fold muscles. Loud, intensive speech, or long sessions of singing all take their toll.
Insufficient hydration may also cause less efficient vibration of the vocal folds and increase throat irritation. Noisy or polluted environments as well as smoking can also lead to excessive vocal strain and irritation of the vocal fold tissue.
Certain types of workers or professionals have the habit of using excessive muscular effort to speak, to project their voice or to sing. This leads to excessive tension in areas such as: the larynx (voice box) where the vocal folds are located; the neck; the upper chest; the tongue or the jaw. Habitual shallow breathing during speech may also reduce the air supply needed to power the voice.
Speakers or singers with inadequate vocal technique may thus experience vocal fatigue and strain. Some may compensate by placing even greater tension on the larynx to produce their voice, therefore aggravating the problem.
Stress and emotion
Our tone of voice conveys our emotions. During periods of extreme stress, negative feelings are sometimes vented through shouting, screaming and other behaviours that may cause injury to the vocal folds.
Other speakers may react to stress by “holding back” and not expressing their feelings. This may lead to a build-up of tension around the larynx. So, even in the absence of excessive voice use, voice production can be impaired.
Stomach acid reflux to the larynx can cause swelling and irritation to the vocal fold tissue, altering the voice quality. Other medical disorders that affect the respiratory system or the larynx may also result in voice problems. A common example would be acute laryngitis.
When assessing the voice, it is important to consider the interaction between all these factors. A unique combination of factors is at play in each individual presenting with a voice problem.
To summarise, a lost voice may be attributed to changes in the structure or functioning of the three subsystems of voice production – respiration, vibration of the vocal folds and resonance/amplification of the voice.