The sound velocities and lattice parameters for sample in the under review paper, "Enhanced visibility of subduction slabs by the formation of dense hydrous phase A", submitted to the journal 'Geophysical Research Letters', are published. The high pressure and high-temperature experiment was conducted in the 1000-ton Kawai type large volume apparatus (T-25) installed at the GSECARS beamline 13-ID-D of Advanced Photon Source, Argonne National Laboratory. The datasets were obtained at conditions up to 11 GPa and 1073 K, using interferometry techniques in conjunction with X-radiographic and X-ray diffraction techniques.

The sound velocities and P-V-T datasets were obtained using interferometry techniques in conjunction with X-radiographic and X-ray diffraction techniques. All the data are collected during cooling process at 200 k interval.