Text: Erik Bouwer

For a short period of time in 2001 there was some commotion in the call centre world. The media made mention of the fact that the British unions were preparing for dozens of claims of call centre employees. The claims were related to ‘acoustic shock’, contracted by working with headsets.
The London lawyer’s office Simpsom Millar acts since the start of the nineties for people claiming to have contracted acoustic shock. In the UK an understanding has been reached for about 300 people with their employer for a total amount of 250.000 euro’s. British Telecom has paid out 90.000 euro’s in one case. In 2006 the Dutch labour inspection received for the first time a complaint of an employee suffering from ringing ears, one of the symptoms of  acoustic shock.

Sound stress
Sound stress occurs in two ways: first of all by the intensity of the stress (the sound level) and secondly by the duration of the exposure to the noise. Noise up to a level of 85 dB is considered as safe. The higher the noise level, the more important it is to shorten the exposure duration. With a sudden noise peak it is possible that, despite the short duration, hearing damage occurs. Most countries know a legislation that sets the maximum allowed sound peak of appliances at 140 dB. Apart from that there are also agreements about the average stress during a workday – an average of 85 dB in a period of eight hours. Every increase with 3 dB shortens the safe exposure duration by half.

Acoustic shock
Acoustic shock is caused when sudden loud noises penetrate the ear. These loud noises have a high intensity and sound like a bang. Also the headset of an agent can be the source of sound for this. Experts say that it is difficult to measure auditory stress in the ear, but the allowed daily limit of 80 dB can be exceeded very easily. But on the other hand, the limit for sudden noises (140 dB) is difficult to exceed with a headset, according to experts. The consequences of overload (peak stress as well as long-term stress) can lead to damage in the inner ear, deafness, (head)ache, nausea, dizziness and tiredness. People can also become oversensitive to louder noises after a peak stress that was too heavy.

Risk factors
Especially people working in a noisy environment, are inclined to set their headset to a hard level; something that was revealed by an important research, done by Jacqueline Patel (attached to the Health & Safety Laboratory in England). The research dates from 2002 and concerned measurements of the noise level of the headsets of 150 British call centre agents, from 15 different British call centres. Most agents participating in the research had turned their volume to maximum strength and were thus exposed to volumes varying from 65 dB to 88 dB. When the present environmental noise (varying between 57 dB and 66 dB) was louder, there were more complaints about not being able to hear the caller well.
The research also showed that there are other risks for the hearing of call centre agents. The dangers lie in fax beeps (that occur less nowadays), tones of mobile phones and beeps when put on hold. These noises appear to be higher than 85 dB in most cases. Also with VoIP connections of a high quality the sound intensity easily reaches a higher level. Another source of problems discovered by the research is the fact that connections of mobile phones are not always optimal. When there’s a bad connection, agents increase the sound volume and thus the chance for peak volumes also increases.

Chance that damage will occur is small
And still Patel concluded her research by claiming that the chance for hearing damage when working at a call centre is very small. She does suggest using headset with a protection module that filters all sudden loud noises. Headsets in England need to stop peak noises above 188 dB. Patel also indicates that it is very important for call centre employees to learn how to use the headset properly: adjusting it right, wearing it in the right way and not increasing the volume. Headsets can be found as external and (semi) internal models and in some cases the headset sounds are intensified by a separate unit. In many cases the headset volume can be adjusted via the telephone, sometimes also via the unit and in some cases via the headset itself. It is very important to keep reminding employees several times a year about the possibilities to adjust the headphones. Headsets should not be shared so that every headset can keep the individual settings and adjustments of its owner.