“…The recommended voice for this type of professional activity is with a comfortable volume, adequate projection, balanced intonation and speech rate, clear articulation, and preferably a vocal quality without any specific markers or hoarseness. Nevertheless, several factors can affect voice production, for instance, lack of necessary vocal health care, required productivity with intense voice use, as well as environmental aspects, such as dust, background noise, air conditioning, lack of hydration and so on (3,8,13) . In 2005, approximately 5% of the US population worked in call centers, compared to 2% in the United Kingdom and 1.5% in Sweden, with a tendency of progression.…”