Ghost in the Machine, by Jonathan Morris

Continuing my intention of blogging Big Finish audios as I listen to them: this is a story with Katy Manning doing Jo Grant, investigating a dangerous entity which exists only as sounds. This is a classic audio story set-up and if anything it's a bit surprising that it hasn't been done to death - I can think of only the early (and fairly successful) Big Finish audio Whispers of Terror, and the Tenth Doctor's excellent final outing Dead Air. Anyway, although I started a little irritated with the initial as-you-can-see-now audio scene setting, once Jo and the Doctor get into the confrontation with the audio creature, helped by the final survivor of the base whose end they are investigating (excellent performance from Damian Lynch), I found myself liking it a lot, particularly the portrayals of different characters from the two cast members; Manning is always at her most effective when pushed to do several things at once.