The robot in GAT is a small homage to the famous singing robot played by Ellen McLain in Portal; GlaDos. This post will take you through the process of creating the robot voice in the Game Audio Tutorial using Melodyne.
(Warning Contains Spoiler )
The dialogue line has been performed in a very monotone staccato manner as to try replicate a robot type voice. It was recorded with a Neumann u87 into an Audient ASP8024 and MOTU 24 I/O.
Charlotte Fotheringham - robot voice actor
The first stage of creating the robot voice is to correct the pitch in Melodyne this snaps the word or part of a word to the nearest note. Listen to the corrected sample
The next stage is to constrain the pitch modulation of the dialogue line this stops the pitch of the dialogue modulating giving it a very synthesised feel.
The penultimate stage is to adjust the dialogue line's formants up two tones. Formants are groups of harmonics present in the dialogue by shifting these up the fundamental pitch remains the same but the harmonics become stretched out, again making the line sound more synthesised.
The last process is where I wanted to differentiate the character from GlaDos slightly. I wanted the character to sound slightly comedic rather than menacing so rather than leaving the pitch constant I pitched individual words up and down by a couple of semi-tones to give the character a jerky musical quality.