Telemarketers talk so much they've been making themselves sick, a new study says.

Researchers have found a link between vocal health and overall health among staff working in the pressure-cooker environment.

The findings could help the $13.7 billion industry find ways of improving call centers to boost the health and productivity of the 220,000 telemarketers employed across Australia.

The study looked at the health of nearly 600 people working in 14 call centers across the UK and Ireland, News.com.au reported.

Sickness levels among call center staff were found to be abnormally high. They worked in stressful environments with excessive background noise and constant sales targets, the study says.

Longer shifts led to workers suffering strained and sore vocal chords, which then impacted their overall health and performance.

In a period over six months, only 31 percent of call center staff in the study had not taken time off work for a voice-related condition, the study says.

Report author Dr. Diane Hazlett, head of communication for the University of Ulster, says the link between vocal health and overall wellbeing should be taken seriously as an occupational health and safety issue for the industry.

One factor contributing to the high rate of sick leave was the employees' perception of their health.

"When someone had perhaps light strain in their voice it appeared as if they felt they were getting a throat infection or they were getting a cold,'' Hazlett said.

"In a sense they overestimated the difficulties they were having to some extent. This was much more likely to perpetuate them taking time off work,” Hazlett said.

The findings were presented at Speech Pathology Australia's national conference held in Melbourne this week.

Hazlett hopes the study can help call centers develop better training for recruits, from using warm-up vocal exercises, limiting background noise and encouraging staff to drink plenty of water.

Call center staff under these conditions are then more likely to be happy, she says, leading to fewer sick days and better results for the company.

While vocal programs have been developed for call centers in the past, voice expert Jenny Oates of LaTrobe University says such initiatives are not standard in the industry.

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