As acousticians, we often see that noise in the workplace is downplayed until employees start complaining about tinnitus or chronic fatigue. Below you will find hard data based on European directives and Polish law, without unnecessary "fluff".

Workplace noise standards - hard numbers (NDN)

In the context of OHS regulations and acoustics, the key concept is NDN, i.e., the Maximum Permissible Intensity. Based on Directive 2003/10/EC of the European Parliament, which harmonizes regulations across all member states, workplace noise standards are strictly defined for three parameters:

1. Steady noise at daily exposure level (8h): The limit is 85 dB.

2. Maximum A-weighted sound level (LAmax): It must not exceed 115 dB.

3. Peak C-weighted sound level (LCpeak): It must not exceed 135 dB.

It is worth knowing that permissible workplace noise standards also provide for so-called "action thresholds." Already at 80 dB, the employer must provide access to hearing protectors, and at 85 dB, wearing them becomes mandatory, and the workstation must be marked.

Noise intensity in the workplace and your health

Why does the European Union take these values so restrictively? Studies by the European Agency for Safety and Health at Work (EU-OSHA) indicate that noise intensity in the workplace above 80 dB causes not only the risk of permanent hearing damage.

It is also a powerful whole-body stressor. Even if noise at the workstation is not "painful," long-term exposure raises cortisol levels, increases the risk of cardiovascular diseases, and drastically reduces concentration. In open-space offices, where informational noise (conversations) dominates, the problem is not decibels but speech intelligibility, which distracts our attention.

Workplace noise measurement – how do we do it?

To determine whether standards are exceeded, a professional workplace noise measurement is necessary. As acousticians, we do not use phone apps for this (which often have an error margin of +/- 10 dB), but calibrated integrating sound level meters, class 1 or 2.

The procedure is as follows:

• We measure noise directly at the employee's ear (using dosimeters) or in the work zone.

• We analyze noise in the work environment, taking into account the duration of individual tasks.

• We calculate LEX,8h - that is, the averaged noise dose an employee "receives" throughout the entire shift.

What is noise? (A brief theory at the end)

Now that you know the limits and risks, it is worth clarifying the fundamentals. The physical definition of noise is any sound of any acoustic character that, under given conditions, is undesirable, harmful, or burdensome to health.

Interestingly, from a psychoacoustic perspective, even a quiet sound (e.g., a dripping tap or a squealing coil in a monitor) can be considered noise if it prevents concentration, even though OHS standards are not exceeded.

Remember: Hearing is a sense that has no "eyelid" - we cannot close it. That is why taking care of acoustics in a company is not only a legal obligation but also an investment in team efficiency.