By then, the voice work had already been recorded for the film, so the name change to "Mrs. Brisby" necessitated a combination of re-recording some lines and, because John Carradine was unavailable for further recordings, careful sound editing had to be performed, taking the "B" sound of another word from Carradine's recorded lines, and replace the "F" sound with the "B" sound, altering the name from "Frisby" to "Brisby".