DHX Media and WGBH Boston have entered production on season four of animated preschool series Martha Speaks.

With the new commission, the co-pro will see its first eps delivered this December to air on PBS Kids in winter 2012, bringing the total number of available eps to 80 half-hours.

Martha Speaks reaches an average of 4.5 million Americans each week and another 745,000 online in the US each month.

DHX Media reps the worldwide television and home entertainment rights outside the US.