Scott Arthur

 voiced several characters for Big Finish Productions.

Bernice Summerfield

 * Paradise Frost - Yukon 9

Gallifrey
As Lukas (from the Regenerators' timeline)
 * Emancipation
 * Evolution
 * Extermination (also as Outsider)

As Lukas (from N-Space)
 * Ascension
 * Intervention Earth