The OASES-OASSP module is the time domain equivalent of the OASS reverberation model. However, in contrast to OASS which directly generates expectation values for the scattered field correlation, OASSP generates timeseries using realizations of the environmental perturbations. Earlier versions of OASSP allowed for rough interfaces with Gaussian or power law power spectra. Version 2.2 and later in addition allows for generating field realizations for scattering from volume inhomogeneities in fluid layers with or without sound speed gradients, based on the theoretical developments of LePage and Schmidt [24]. OASSP is used in conjunction with OASP, which is used for computing the mean, coherent field, which is driving the scattering. The data files for OASSP are very similar to those of OASP, and OASSP generates a transfer function file in the same format, which is post-processed and plotted using PP. As is the case for all the other modules, both stresses and particle velocities can be computed.