ATERIAL_COEFFICIENTS</h3>
              <div class="symbol-detail-labels"><span class="label label-static"><small>static</small></span></div>
              <p class="type-signature">Object</p>
              <p>Pre-defined frequency-dependent absorption coefficients for listed materials. Currently supported materials are:</p>
              <ul>
                <li>'transparent'</li>
                <li>'acoustic-ceiling-tiles'</li>
                <li>'brick-bare'</li>
                <li>'brick-painted'</li