Hoarseness: Voice Risks for Call Centre Staff and Teachers

Who is affected by occupational hoarseness?

If a voice that is clear on Monday morning is hoarse by Friday evening and comes back after resting at the weekend, the problem most likely lies in the work itself. Occupational hoarseness is seen in workers who use their voice intensively and for long periods:

• Call centre workers: Talk almost continuously throughout the shift, often in a noisy room and with a headset.
• Teachers and trainers: Raise their voice in crowded, echoing classrooms and in back-to-back lessons; physical education teachers teach outdoors by shouting.
• Other voice professions: Sales advisers, tour guides, coaches, workers making announcements and supervisors giving verbal instructions in noisy production areas.

The voice is produced by the vibration of the vocal cords in the larynx. When the vocal cords are overused and strained, swelling and irritation begin on their surfaces. As this is repeated, permanent changes can develop; the best known of these is the vocal cord nodule. A nodule is a hardening that usually forms where the two vocal cords strike each other, causing the voice to become deeper, rough and quickly tired.

Vocal fatigue, nodules and other findings

Being able to distinguish the symptoms is a precondition for workers and supervisors to take early action:

Nodules can only be distinguished from other vocal cord diseases when the larynx is visualised by an ear, nose and throat specialist. The American Academy of Otolaryngology's clinical practice guideline on hoarseness recommends examination of the larynx for hoarseness that does not resolve within four weeks, or regardless of duration if a serious cause is suspected.

Call centre vocal fatigue: environment and work organisation

Most of the factors that increase call centre vocal fatigue are not within the worker's control. People raise their voices without realising it in a noisy environment; when everyone in a crowded call room speaks a little louder, background noise rises and the cycle grows. Measures should therefore start with the environment:

1. Acoustic layout: Sound-absorbing panels between desks, acoustic materials on ceilings and walls and desks not facing each other reduce background noise. For noise reduction methods at source, see our article on reducing noise at source.
2. Headset and microphone: An adjustable binaural headset with a noise-cancelling microphone makes it easier for workers to hear their own voice and reduces the need to shout. Headset volume should also be assessed separately for hearing health.
3. Breaks and work allocation: Art. 7 of the Regulation on Display Screen Equipment requires the employer to plan periodic breaks or changes of activity for work with display screen equipment. In a call centre, these breaks should be organised as breaks in which the voice also rests; the regulation does not set a limit in minutes, and the interval is determined by the risk assessment and the workplace physician. For details, see our article on working with display screen equipment.
4. Performance targets: Targets that leave no gap between calls remove breathing and water breaks. Voice load should also be taken into account when setting targets; for the relationship between workload and stress, see our article on sources of work stress and measures.
5. Air quality: Air dried by air conditioning irritates the vocal cords. Humidity and temperature complaints should be taken seriously, and workers should be allowed to keep a lidded water container at their desk.

Teacher voice health: classroom conditions

The most important factor determining teacher voice health is the classroom itself. In an echoing, crowded classroom exposed to outside noise, teachers have to raise their voice throughout the lesson. Practical measures for school management and the employer are:

• Classroom acoustics: Acoustic material on ceilings and walls in hard-walled, echoing classrooms, felt pads on desk legs and window arrangements against outside noise.
• Voice amplification: Use of portable microphones and speakers in large classrooms, sports halls and outdoors.
• Timetable: Placing tasks that do not require the voice between lessons rather than giving the same teacher many consecutive lessons.
• Break duty: Methods that do not require the voice, such as whistles or hand signals, instead of shouted warnings in a crowded playground.
• Periods of illness: A teacher with an upper respiratory tract infection should not strain their voice.

Following the Constitutional Court ruling, the postponement of the specialist and physician obligation for public institutions and less hazardous workplaces with fewer than 50 workers has also ended; public schools, like private schools and courses, are within the scope of this obligation. For topics specific to private schools and courses, see our article on OHS in private schools and courses.

Vocal hygiene: practical advice for workers

Vocal hygiene is the set of daily habits that protect the voice. The following advice can be covered in induction or job-specific risk training:

• Drink water regularly throughout the day; the vocal cords are strained less when they stay moist.
• Do not shout, but do not whisper either; whispering also strains the voice. Speak in a normal, comfortable tone.
• Instead of clearing your throat forcefully, swallow or take a sip of water.
• Talk less during breaks; do not turn the lunch break into a loud meeting.
• Stay away from smoking and cigarette smoke.
• If you have heartburn or reflux, tell your doctor; reflux can irritate the vocal cords.
• Do not strain your voice when you are ill, and inform your supervisor.
• Only do voice exercises and warm-ups on the recommendation of an ear, nose and throat specialist or voice therapist.

What does the workplace physician do? Symptoms requiring referral

The workplace physician's role is not to treat hoarseness as normal "because of the job", but to identify complaints systematically:

1. Pre-employment examination: For voice professions, a voice history is taken: previous voice complaints, ear, nose and throat treatment, smoking and reflux.
2. Periodic examination: Voice complaints and the duration and frequency of hoarseness are recorded; if more than one worker in the same team has complaints, the environment and work organisation are examined.
3. Referral: For hoarseness lasting more than four weeks and symptoms requiring urgent assessment, the worker is referred to an ear, nose and throat specialist.
4. Fitness for work and adjustment: During treatment, it may be recommended that the worker is temporarily given work requiring less speaking or that their voice load is reduced.
5. Suspected occupational disease: Law No. 6331 on Occupational Health and Safety defines occupational disease as a disease arising from exposure to occupational risks. Which diseases count as occupational diseases is determined by the Annex 2 list of the Regulation on Procedures for Determining Loss of Working Capacity and Loss of Earning Capacity in Occupation; the assessment is made by authorised health boards and the Social Security Institution (SGK). The workplace physician's duty is to record the suspicion and start the process; for the steps, see our article on the physician's role when occupational disease is suspected.

Workers' health information is confidential; for the limits on sharing, see our article on employee health information and the Personal Data Protection Law (KVKK). At call centres, schools and courses in Bursa and the surrounding provinces, we carry out the examination and follow-up of voice complaints as part of our workplace physician and health surveillance services. For other sector-specific topics, see our office and retail page.

Checklist for employers

• Is voice load included as a separate hazard for voice professions in the risk assessment?
• Have acoustic measures been assessed in the call room or classroom?
• Are headsets and microphones suitable for the work, personal to each worker and well maintained?
• Are breaks and work allocation planned to allow the voice to rest?
• Can workers easily access water at their desk or in the classroom?
• Is vocal hygiene covered in training?
• Are voice complaints asked about and recorded at periodic examinations?
• Is there a written procedure for referral and temporary work adjustment in cases of prolonged hoarseness?

You can plan periodic examination dates with the OHS calendar.

Frequently Asked Questions

Is a vocal cord nodule considered an occupational disease?

Whether a disease counts as an occupational disease is determined according to the list of occupational diseases in the regulation and the assessment of authorised health boards and the SGK. The workplace physician records a vocal cord disease suspected to be work-related and refers the worker.

How often should voice breaks be given in a call centre?

The legislation does not set a break length in minutes. The Regulation on Display Screen Equipment requires periodic breaks or changes of activity to be planned; the interval is determined by the risk assessment and the workplace physician, taking call volume and voice load into account.

When does hoarseness require a visit to the doctor?

An ear, nose and throat assessment is needed for hoarseness lasting more than four weeks, or for symptoms such as sudden loss of voice, shortness of breath, coughing up blood, difficulty swallowing and swelling in the neck.

Does using a microphone really make a difference for teachers?

In large classrooms, sports halls and outdoors, a voice amplification system allows the teacher to be heard without straining their voice. It is more effective when used together with improving classroom acoustics and adding voice breaks to the timetable.