Jump to main content
Jump to site search

Issue 4, 2017
Previous Article Next Article

Optimal sound-absorbing structures

Author affiliations


The causal nature of the acoustic response dictates an inequality that relates the two most important aspects of sound absorption: the absorption spectrum and the sample thickness. We use the causality constraint to delineate what is ultimately possible for sound absorbing structures, and denote those which can attain near-equality for the causality constraint to be “optimal.” Anchored by the causality relation, a design strategy is presented for realizing structures with target-set absorption spectra and a sample thickness close to the minimum value as dictated by causality. By using this approach, we have realized a 10.86 cm-thick structure that exhibits a broadband, near-perfect flat absorption spectrum starting at around 400 Hz, while the minimum sample thickness from the causality constraint is 10.36 cm. To illustrate the versatility of the approach, two additional optimal structures with different target absorption spectra are presented. This “absorption by design” strategy would enable the tailoring of customized solutions to difficult room acoustic and noise remediation problems.

Graphical abstract: Optimal sound-absorbing structures

Back to tab navigation

Supplementary files

Publication details

The article was received on 01 Mar 2017, accepted on 15 May 2017 and first published on 16 May 2017

Article type: Communication
DOI: 10.1039/C7MH00129K
Mater. Horiz., 2017,4, 673-680

  •   Request permissions

    Optimal sound-absorbing structures

    M. Yang, S. Chen, C. Fu and P. Sheng, Mater. Horiz., 2017, 4, 673
    DOI: 10.1039/C7MH00129K

Search articles by author