We are continuously beset by sounds. Desired, as well as undesired, sounds affect the quality of our lives. Voices need to be totally intelligible sometimes but not so, or even inaudible, at other times. Noise pollution can cause health problems such as sleep deprivation, stress, high blood pressure and cardiovascular disease. That’s why, in addition to good acoustics, you look for the best sound insulation for an ideal living and working environment. Heraklith wood wool panels contribute to a good sound environment from all these aspects.

Heraklith for sound absorption

Sound absorption material is often used to reduce reverberation in a space or to eliminate specific reflections or echoes. This improves the intelligibility of speech and reduces the level of (disturbing) noise. There are a variety of situations where this is desirable, with Heraklith often used in functional areas such as workshops, factory halls, traffic areas, parking garages, sports facilities, stations, tunnels and balconies. Please refer to our Organic acoustic panels for more aesthetic applications of wood wool panels.
 

In many of the types of spaces mentioned, the objective is not only to control reverberation and noise, but to make a public address system or evacuation system intelligible. There, Heraklith can be used on ceilings and walls.

Heraklith for sound insulation

Sound insulation is achieved in two ways: reduction of the sound level in the emanating space using sound absorption material (see above), and exclusion of sound by means of a separating structure. Heraklith plays a role in both cases, as illustrated in the figure with garage ceiling. A large portion of the incident sound (3) is absorbed by the absorption material (2), a small portion is returned to the room (4), and a small portion is transmitted to the structure or space beyond (1). The total contribution of sound absorption material is often a few dBs to about 10 dB. A substructure is also required to obtain sufficient total sound insulation of, for example, 40, 50 dB or more.

Sound absorption coefficient

The degree of sound absorption is expressed as a value between 0 and 1. The figure with the garage ceiling illustrates that the sound absorption coefficient consists of the ratio of the converted + transmitted energy (1+2) to the total incoming energy (3). In practice, the portion of transmitted sound is negligible (<0.001) and the sound is completely absorbed by the wood wool panels installed in front of the substructure.

The open pore structure of Heraklith wood wool panels with a special acoustically open paint layer ensures optimal absorption of sound energy. Here, the thickness of the panel and any cavity with or without mineral wool determines the pitch at which the sound can be absorbed. To clarify this further, we list sound absorption coefficients for frequency bands from 125 to 4,000 Hz in the tables below. It can be seen that a thicker structure generally performs better with bass tones, while the performance with treble tones hardly changes at all. In addition to the absorption values for different frequency bands, the tables also show single-number ratings that indicate weighted or average values over part of the frequency range: α_w (250-4,000 Hz), NRC (250-2,000 Hz), and SAA (250-2,000 Hz).
 

Do you want to improve the acoustics in an interior? Then take a look at our Organic brand.