Ключевые слова: absorb, absorbers, abstract, anechoic, anechoic chamber, attenuation, audio, broadband, electromagnetic, electromagnetic compatibility, emc, emi, engineering, environment, foam, free space, frequency, green, hybrid, lab, laboratory, magnetic, material, microwave, military, nobody, pattern, pyramidal, pyramidal absorbers, pyramids, radio, research, rf, science, scientific, shielding, silent, sound, spikes, technology, testing, wave propagation,