Australia Model Code of Practice Managing Noise and Preventing Hearing Loss at Work 6.4-CONTROL: Control acoustic shock in headset work: high-quality headsets with acoustic shock protection, prompt repair of damaged equipment and network faults, proper fitting, use and maintenance of headsets, reduced background noise through room and workstation design, absorption, barriers, quiet conduct, relocated office machines and managed hot-desk changeovers, training to detect warning sounds and remove headsets, turning volume down after changeover, managing psychosocial hazards, keeping mobile phones out of call centres, and baseline audiometry at commencement

What does 6.4-CONTROL require?

Acoustic incidents are sudden, unexpected loud sounds heard through a telephone headset: crackles, hisses, whistles, shrieks or high-pitched tones. They originate in faulty or damaged networks, phones or headsets, broadband or narrowband interference, mobile phones or fax machines used inside call centres, misdirected fax and modem tones, or at the caller's end from cordless phone feedback, alarms, receivers slammed down or dropped, or noises made right at the mouthpiece. Acoustic shock is the body's reaction to the abrupt jump in level rather than to loudness, since telephone output is electronically capped at a 123 decibel peak; only a small share of incidents produce it. Loud rooms raise the risk because operators turn their headsets up, and tension or middle-ear inflammation may add to it. Symptoms span immediate ear fullness, burning or sharp pain, numbness or tingling down the face, neck or shoulder, nausea, dizziness and tinnitus; then headaches, fatigue, imbalance and anxiety; then hypersensitivity to ordinary sounds and hypervigilance, with anger, withdrawal or psychological injury in some people, though hearing loss is rare. The controls: supply high-quality headsets fitted with acoustic shock protection; attend promptly to damaged equipment and network faults, with the supplier or an acoustic specialist where needed; see that headsets are fitted, used and maintained properly; cut background noise by reviewing room and workstation design and layout, reducing outside and building-service noise, damping reverberation with absorbent materials, placing acoustic barriers around and between workstations, discouraging loud talk near operators, siting fax machines, photocopiers and printers away from them, controlling radios and mobile phones, and managing hot-desk changeovers quietly with space to move; train operators to recognise warning sounds (a cordless phone too near its base, for example) and to know when to pull the headset off fast; make hot-desking staff turn the volume down straight after a changeover; manage psychosocial hazards; and keep mobile phones out of the call centre. To help diagnose any later hearing loss, consider having a specialist test every operator's hearing when they start, to set a baseline.