Ayres was hired after he sent producer John Nathan-Turner a demonstration video containing music he had written to accompany Remembrance of the Daleks.
Ayres was also involved in the last days of the BBC Radiophonic Workshop, cataloguing and archiving their recordings for future use.
Ayres compiled and produced the CD Who Is Dr Who, released in 2000 by Cherry Red Records division RPM.
He has also contributed to the DVD commentaries for several releases of the BBC's Doctor Who range (Planet of Giants, Terror of the Zygons, Paradise Towers, Dragonfire, The Greatest Show in the Galaxy and Ghost Light).
Ayres composed a new musical score for the colourised "blockbuster edit" of The Daleks, released in 2023.