system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] Why didn't the trade federation recognize that Palpatine and Sidious had the same voice?

Wouldn't this have made it obvious that they were the same person. They heard both voices.
gpt
Sidious was a master manipulator. He could talk right to your face about some deep dark secret, and you would walk away thinking of the opera that he *just* told you about. The force let him effect it to an even greater extent.

Also, by the point that you were able to realize that they were the same voice, you'd be already in pretty deep. At that point, they probably knew, but were wise enough not to say anything.