In natural draft wet cooling towers, the dripping of the cooling water into the collecting tank causes a disturbing noise. The frequencies are generally above 500 Hz with the sound pressure level being more than 80 dB(A). The sound pressure level is higher at the air intake.

Fan operated wet cooling towers typically have a fan noise in the frequency range between 30 and 500 Hz and the water noise between 500 Hz to 4 kHz. The total sound pressure level of the wide band noise at the air intake is usually higher than in natural draft cooling towers.

Depending on the required reduction, cooling-tower sound-attenuation measures are divided into sound absorbing walls and splitter silencers. Using these techniques provides reduction up to 12 dB (absorbing walls) and 30 dB (silencers), respectively. The splitter silencers are normally made of seawater resistant aluminum, and BBM Akustik Technologie offer these in lengths as long as 15 m (50 ft).

Due to the required volume of silencers and the corresponding costs, cooling tower silencers have to be optimized regarding their pressure drop and noise reduction.

To obtain acoustic and flow readings, BBM Akustik Technologie has various test-rigs and the latest measuring and analyzing equipment.