Question

absorbing sounds
attenuation coefficients are a measure of
how well a material absorbs waves. these
values range from 0 to 1, with 1
representing complete absorption of
compressional waves. review the
information in the table and the images in
the gallery and answer the question.

1. what kind of feature makes for a good

sound - absorbing material?
acoustic foam

material\tattenuation at 500hz
concrete\t0.3 - 0.4
wood\t0.06 - 0.1
acoustic foam\t0.7

Explanation:

Looking at the attenuation values, acoustic foam has the highest coefficient (0.7, closest to 1 which is full absorption). Acoustic foam has a porous, cellular structure that traps sound waves, converting their energy into small amounts of heat rather than reflecting them back. This porous, soft, and non-rigid structure is the key feature that makes it an effective sound absorber, unlike dense, rigid materials like concrete or wood which reflect more sound.

Answer:

A porous, soft, cellular (non-rigid) structure that can trap and dissipate sound wave energy, rather than reflecting it, makes for a good sound-absorbing material (exemplified by acoustic foam's structure).