Voice Over is the first part of the 10th episode in season 4 of Dexter's Laboratory, which first aired on September 19, 2003. In this episode, Computer suffers from a voice malfunction, and Dexter tries to find a replacement voice for her.
In the morning, Computer powers up the laboratory just as Dexter gets out of bed for the day. The boy genius goes around doing his morning duties, and goes to prepare for work. As Computer loads up her voice chip, she gets an error upon doing so and communicates to Dexter by writing out messages on her screen. Dexter orders her to fix her voice, and soon changes his mind when Computer shows him how long it would take. He then takes matters into his own hands, and goes inside Computer's motherboard. There, Dexter wrenches the bolt on Computer's voice chip and comes out shortly after.
For the first test, Computer starts telling jokes with a new voice, which cracks Dexter up. As Dexter is working, Computer's jokes start getting corny and makes an insult towards Dexter. Dexter heads back inside the motherboard and wrenches the voice chip some more. After the second test, he goes back to work. As Dexter works, Computer's voice starts making him very nervous. He wrenches as fast as he can as Computer talks away about information. He heads back inside the motherboard and wrenches the voice chip some more.
For the third test, Computer's new voice orders Dexter to input the number of an invention he's working on. Shortly after, Dexter gets annoyed and goes to wrench the voice chip once more. After Dexter leaves, Dee Dee's voice rings into the system, causing Dexter to go back inside. Later, Computer starts sounding like Michael Buffer as Dexter works on his invention. He changes the voice chip into a Spanish voice, which Dexter has a hard time understanding.
On the last voice, Dexter starts coughing and goes back to work with earmuffs in his ears. After a long day, he leaves the lab and goes to bed. The next day, Computer's voice is back to normal. Dexter enters the lab and tells her he has laryngitis. He then goes back to working on his invention.