Hearing loss at call centres

Noise-induced hearing loss is the second most common occupational disease. For years it was believed that being a call-centre operator was a low-risk occupation. But personal-injury claims from call-centre workers are on the rise.

In 2012 – 13, Professor Setsuo Maeda of Kindai University*, Japan carried out research at a call centre on the island of Okinawa. Dr Maeda compared the noise-exposure risks and speech intelligibility of traditional headsets with those of the latest bone-conducting devices, using technology from Brüel & Kjær.

Challenge

No scientific, controlled acoustic experiments had been conducted with actual call-centre workers to compare the two leading headset technologies. There was a need to establish baseline measurements and to conduct carefully monitored changes in hearing. This required a carefully designed experiment coupled with highly sensitive measurement equipment.

Solution

Using a Head and Torso Simulator (HATS), measurements were made over a six-day period. To evaluate the relative merits and dangers of the two alternative systems, incoming call signals were divided between two headsets used in parallel by HATS and workers making real calls. A Personal Noise Dose Meter Type 4448 was also used.

Results

“My conclusion is that hearing damage could occur at levels above 90 dB(A),” says Dr Maeda. He has also reported: “bone conducting devices help to prevent hearing loss.” This has since been confirmed by studies carried out at the University of Southampton in the United Kingdom – to the benefit of call-centre workers the world over.

* Formerly Kinki University