In the answer to question no. 14488 there is a fatwa of the Standing Committee which states that it is haraam to act the part of any of the Companions of the Prophet (blessings and peace of Allah be upon him) in movies, plays and so on.
In those answers it also says:
There is no difference between voice acting and acting that is seen.
There is no difference of opinion among the scholars that acting which involves indecency, free mixing or any haraam content or actions is haraam.
None of the scholars permit acting in general terms; rather they have stipulated conditions and guidelines.
It is not appropriate to do a great deal of permissible acting -- according to those who say that it is permissible -- even if that is for the sake of calling people to Allah.
After searching a great deal, we did not find any fatwa by any of our senior scholars that speaks specifically of voice acting. What seems to be the case is that there is no difference between voice acting on the radio and acting that is seen, as it is all acting, whether the view is that it is permissible or that it is forbidden. But there is no doubt that acting that is seen is more serious in terms of fitnah and causes more corruption, because temptation caused by a living, visible image is not the same as temptation caused by a voice that is merely heard. But we are speaking of acting in and of itself, regardless of what other things may accompany it.
And Allah knows best.