Hearing frequency spectrum – definition and significance in noise protection
The hearing frequency spectrum describes the frequency range in which the human ear can perceive acoustic signals. It typically ranges between 20 Hz and 20,000 Hz (20 kHz). Within this spectrum, our ears are particularly sensitive to certain frequencies – for example, between 500 Hz and 4,000 Hz, which is where speech and everyday noises lie.
Why is the hearing frequency spectrum relevant in noise protection?
- Targeted sound insulation: Materials such as those from Cellofoam are developed to be particularly effective at dampening frequencies that are critical to human hearing.
- Health protection: Constant exposure to sound in the audible frequency range – especially at high levels – can lead to stress, concentration problems and hearing damage.
- Application optimisation: In industry, vehicle construction and building services engineering, particular attention is paid to attenuating those frequencies that are perceived as disturbing or harmful to health.
Technical implementation at Cellofoam
Cellofoam relies on acoustically optimised foams and non-woven materials, which enable high sound absorption across a wide frequency range thanks to their structure and material combination. These products achieve effective noise reduction, particularly in the mid-range hearing range.
For effective attenuation of low frequencies – below 500 Hz, for example – Cellofoam offers special product solutions that go beyond classic foams:
- Cello® BBA: This broadband absorber consists of multi-layer composite panels with heavy foil and PUR foam. The combination acts as a resonance absorber and is particularly effective at low frequencies.
- Cello® 521: A convoluted foam with excellent airborne sound absorption across all frequency ranges – even in the low frequency range.
- Cello® 471: PUR acoustic foam with an air-permeable sealed surface, which achieves good absorption values even at lower frequencies thanks to its structure.
Through targeted material combinations – for example with heavy foil or convoluted foam – resonance effects are used to absorb low-frequency sound. The products are often modular in design and can be adapted to suit the application.
