Acoustic device including a member extending transversely of its thickness
and capable of sustaining bending waves at least over an intendedly consequentially
acoustically active area of the transverse extent of said member, the member having,
by reason of orderly design methodology disclosed and claimed, a distribution of
resonant modes of its natural bending wave vibration at least over said area that
is dependent on values of particular parameters of said members, including geometrical
configuration and directional bending stiffness(es), which values have been selected
to predetermine said distribution of natural resonant modes being consonant with
required achievable acoustic action of said member for operation of said device
over a desired operative acoustic frequency range.
