Millions of workers at call and dispatch centers use headsets during most of
their workday. They mainly include dispatchers, medical transcriptionists, air
traffic control specialists, customer service representatives, switchboard
operators, reservationists, and bill collectors. Many work in high-pressure,
stressful environments with noisy surroundings and poor ergonomic conditions.

Background noise in the workplace (radios played by other workers,
conversations, noise from heating and air conditioning systems) or from the
callers' locations may cause workers to turn up the headset volume, resulting
in sudden increase in noise levels transmitted into their ears. Some
communication systems may experience feedback or interference that could cause
spikes or squeals from the headset. Some workers complain of fluctuations in
noise levels in the headset or having little control over headset volume.

The The Us-American National Institute for Occupational Safety and developed
recommendations for prevention.

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AplusA-online.de - Source: National Institute for Occupational Safety and Health (NIOSH)