  The memory effect, in the context of gravitational-waves (GWs), manifests
itself in the permanent relative displacement of test masses when they
encounter the GWs. A number of works have explored the possibility of detecting
the memory when the source and detector are separated by large distances. A
special type of memory, arising from BMS symmetries, called ``black-hole
memory'', has been recently proposed. The black hole memory only manifests
itself in the vicinity of its event horizon. Therefore, formally observing it
requires placing a GW detector at the horizon of the BH, which prima-facie
seems unfeasible. In this work, we describe a toy model that suggests a
possible way the black hole memory may be observed, without requiring a
human-made detector near the event horizon. The model considers a binary black
hole (BBH), emanating GWs observable at cosmological distances, as a proxy for
an idealized detector in the vicinity of a supermassive Schwarzschild black
hole that is endowed with a supertranslation hair by sending a shock-wave to
it. This sudden change affects the geometry near the horizon of the
supertranslated black hole and it induces a change in the inspiraling orbital
separation (and hence, orbital frequency) of the binary, which in turn imprints
itself on the GWs. Using basic GW data analysis tools, we demonstrate that the
black hole memory should be observable by a LISA-like space-based detector.
