Gravitational Sound clips produced by the Laser Interferometer Gravitational-Wave Observatory (LIGO) and the Massachusetts Institute of Technology (MIT) are considered within the particular context of data reduction. It is shown that these types of signals can be approximated at high quality using much less elementary components than those required within the standard orthogonal basis framework. Furthermore, a measure a local sparsity is shown to render meaningful information about the variation of a signal along time, by generating a set of local sparsity values which is much smaller than the dimension of the signal. This point is stressed further by recourse to a more complex signal, generated by Milde Science Communication to divulge Gravitational Sound in the form a ring tone.

Routines for implementing the approach are available on http://www.nonlinear-approx.info/examples/node05.html