In this episode they screw up with the voice of the voltorb. As pokemon fans know. voltorb voice is something very robotic that made with special sound effects.
Voltorb voice is also need to be higher then electrode.
Anyway. Its a big screw up because the following reasons:
First: The voltorb in this episode sound just like
the voice of electrode (Don't get mistaken. he is still saying its name like any other pokemon)
Second: At the end of the episode when ash and his friends say good bye to voltorb his voice is suddenly without any electronic effects , they just got someone to say: "Voltorb! voltorb!"
with No special sound effect! I guess they was running out of money or they just been lazy but I think its another big screw up that the USA voice actors of pokemon did...