Structured pre-form bodies as panel lining for wide-band sound absorption
are made of an open-cell foam material having a rigid framework
co-vibrating in a resonant manner at low frequencies. The pre-form bodies
have a base layer and a columnar structure positioned directly in front of
or on the base layer. The columnar structure has a non-symmetrical
distribution of height and cross-section, thereby forming a wide-band
tuned moderator gap and the columnar height corresponds approximately to
the density of the base layer. The columnar structure has a framework
resonance adjustable as a function of parameters of the base layer.
