Mono-a-Mono is an audio enhancement program designed to remove scratches and tape or surface noise from stereo recordings of mono sources. It can be used to enhance digital recordings of old records (78, 45, or 33 rpm, shellac, acetate or vinyl), and even audio tapes (reel-to-reel or cassette).

It uses a simple muting algorithm to remove the most obvious clicks, and then filters the signal to remove any components which are not present in both left and right channels. In this way, almost all the audible surface noise is removed, and there are very few cases where any significant artefacts are introduced.