  Listening to echoes has long been a way to estimate distances, a technique
whose backbone is the time delay. The gravitational field also creates a time
delay, called Shapiro time delay, that helps us extract some information from
the field and is indeed due to the photon journey through the field. Here, the
ability of the Shapiro effect to distinguish naked singularities from non-naked
ones (black holes) is discussed. It is also inferred that this time delay may
be hired to compare the various types of singularities with different
dimensions. Besides them, the possibility of detecting the rotation of the
assumed objects through surveying the gravitational time delay is also
addressed.

General Relativity and Quantum Cosmology