Room acoustics

Noise, even of low intensity, can disturb concentration and well-being in rooms significantly – particularly when performing mental activities.

Sound sources located within a room or outside of it influence the acoustic climate of a room in connection with the room’s acoustic properties, particularly sound absorption of floors, walls and ceiling as well as objects located within the room.

Sound sources perceived as disruptive can be machines of all types, e.g. office appliances or components of ventilation and air conditioning installations – but also electrical equipment such as luminaires.

Usually, the cause of noise in luminaires is one of the following:

• humming control gear units in luminaires for fluorescent lamps with magnetic control gear (LLCG);

• humming LED control gear with pulse-width modulation (PWM), typically in the PWM frequency range (ca. 500 Hz, see chapter "Flicker and stroboscopic effects")

• so-called diffuser clicking upon switching on diffuser luminaires, which can be resolved or reduced by treating diffuser fasteners with wax as needed;

• vibrations of luminaire components or unstable ceiling systems, which usually indicates construction defects in the product; or

• flow noise in ventilated luminaires as described in section .