Generally, in a non-destructive test application, a compressed representation of an acoustic echo signal acquired by a non-destructive test (NDT) probe assembly can be received, such as via a network. The compressed representation can include data indicative of changes in phase values of the acoustic echo signal. Using the compressed representation, a time-domain representation of an instantaneous phase signal can be constructed from the compressed representation. The constructed instantaneous phase signal can be used in constructing at least one of an uncompressed acoustic echo signal representation or an image. As an illustration, amplitude values of sampled acoustic echo signals can be suppressed in the compressed representation, reducing data volume associated with transmitting a representation of the acquired acoustic echo signal.