Air that is too dry is uncomfortable and dangerous, especially for jobs that involve a great deal of speaking and screen work. All too often, the direct correlation here to the indoor climate is not recognised. Dryness in the throat and larynx, clearing of the throat and a persistent cough are always the first alarm signals. At the latest when the voice becomes hoarse, or is lost altogether, performance on the job suffers.
To maintain good voice function and prevent voice disorders, adequate moistening of the mucous membranes is therefore necessary. For professions involving a great deal of speaking, a minimum humidity of 40% is recommended.
Fewer problems with the voice with optimal humidity
There are many factors that work together to produce problems with the voice: aside from causes specific to individuals (e.g. poor speaking technique), these are mainly factors in the working environment such as loud background noise, a poor indoor climate or an incorrect posture while sitting. The climate, and in particular the humidity of the climate, has a critical influence on the voice: to maintain good voice function and prevent voice disorders, adequate moistening of the mucous membranes is necessary. When we speak, air is pushed out of the lungs through the larynx. This causes the vocal folds to vibrate and, like the strings of a guitar, to produce tones. If the humidity is too low, the mucous membranes of the vocal folds lose their optimum moisture level, and hence their elasticity. The glottis can no longer be fully closed by the vocal folds after breathing in. Additional air finds its way into the vocal tract, leading to irritation, inflammation, and in the worst case loss of the voice.
Research shows, for instance, that over 60% of employees in call centres or customer service departments suffer from voice strain. Common symptoms are dryness of the throat and larynx, more frequent clearing of the throat, and hoarseness. “These symptoms distract the listener from what is being said and cause significant disruption to communication with the customer,” says speech therapist and voice coach Thomas Niemann of Sprechfreunde.de. The potential consequences include loss of quality of discussion and lower closure rates. In addition, voice disorders are often associated with absence rates: respiratory problems, which include hoarseness and laryngitis, are one of the main causes of sick leave at call centres. With the number of staff away sick not infrequently in the double digits, this involves significant costs and loss of performance for companies. To maintain good voice function and prevent voice disorders, adequate moistening of the mucous membranes is therefore necessary. For professions involving a great deal of speaking, a minimum humidity of 40% is recommended. By retrofitting humidification systems, companies can make a major contribution to improved health and quality of conversation in the workplace.
Case studies: Humidification and the voice
Protection of the voice at the coffee specialist Jura