The acoustical product of the present invention comprises an acoustical
product including a matrix of calcium sulfate dihydrate crystals and
expanded perlite distributed throughout the matrix. The expanded perlite
has a particle size distribution with at least 10% of the perlite having
a particle diameter of 700 microns or more, and the amount of expanded
perlite to calcium sulfate dihydrate is about 35% to about 75% by weight,
based upon the dry weight of the calcium sulfate dihydrate. A dispersing
agent and glass fibers having a particle length of about 1/4 inch to
about 1 inch are dispersed throughout the gypsum matrix.