Temporal changes in the subsurface seismic velocity structure reflect the physical processes that modulate the properties of the media through which seismic waves propagate. These processes, such as healing of the surface damage zone and deep crustal deformation, are described by similar functions and operate on similar timescales, making it difficult to determine which process drives the observed changes. We examine earthquake-induced velocity changes using the measured lag-time time series () of the repeating earthquake sequences since the 2004 M 9.2 Sumatra and 2005 M8.6 Nias earthquakes. The -coda velocity changes (, equivalent to ) recover steadily during the 2005−2015 period. The Rayleigh wave velocity changes (, or ) undergo transient recovery, followed by a strong reduction in late 2007. recovery is most likely driven by deep processes, whereas the temporal breaks in recovery in 2007 reflect surface damage and healing induced by the strong ground motions of the 2004 M 9.2, 2005 M 8.6, 2007 M 8.4 and M 7.9 Bengkulu, and 2008 M 7.3 Simeulue earthquakes. The observed differences between the temporal variations in and can distinguish deep processes from healing of the surface damage zone.