Noise issues in industrial environments

The Issue

According to the “noise at work” regulation, when the employee is exposed to a level of 85 dB(A) over a period of 8 hours, hearing protection must be worn because this level of noise presents a medium/long-term risk to hearing.

The employer is forced to reduce the noise to the lowest reasonable level and can consult Metravib for this purpose.

To reduce noise levels and propose adapted solutions, Metravib teams will first have to determine what kind of noise has to be considered:

• Airborne noise generated by sources that do not transmit vibrations to the host structure. Noise is then propagated by air.
• Structure-borne noise generated by sources that are related to the industrial equipment transmitting vibrations to the host structure. This type of noise is generated by the vibration of the equipment.

In most cases, it is a combination of airborne and structure-borne noise.

The Solution

Noise characterization is achieved with suitable equipment:

• Airborne noise: Measurements with acoustic antennas, intensity probes, sound level meters…
• Structure-borne noise: Accelerometers, laser vibrometers, transmissibility characterization with shock hammer or shaker.

According to the identified noise, configuration of the industrial equipment and customer’s requirements, Metravib will suggest different noise reduction solutions (anti-vibration devices, dynamic absorbers, soundproof cabin or curtains, shielding, acoustic correction…)