How'd they do Soundwave's voice?
All of the voices on the show were altered to make them sound more robotic and less human. The process they used is called flanging, which means that a stereo recording was made of the voice actors, and then one channel of the sound was slightly delayed in a random fashion to produce that "robot" sound in all their voices. You can download a shareware sound-editing program called "Cool Edit" which has a flanging feature to play with.
For Soundwave in particular, the voice recording was given some extra processing. According to Kendrick, a long-departed ATT god, the recording was sent through an analog synthesizer to remove "all the tonality but none of the enunciation or cacophonous sounds." The removed tones were then replaced artificially by someone on the voice processing team to produce the cool-sounding voice we all know and love. Don’t ask me what that all means, though, because I don’t have a clue.
When performing Soundwave, Frank Welker used his basic growling villain voice. You can hear practically the same voice coming out of Dr. Klaw on "Inspector Gadget". Occaisionally, through mistakes on the part of the TF production team, bits of Welker’s unaltered voice ended up in the cartoon. In "Roll For It", when Ravage brings Chip and some vital info to Soundwave, he says "Excellent, Ravage" in a Dr. Klaw voice. This also occurred in "Webworld", when Soundwave reports that Ratbat has found something on a nearby asteroid. In addition, in "Fight or Flee" Soundwave ended up speaking with Shrapnel's characteristic repetition of his last word.
Cool Edit, sound clip editor with flanging feature:
http://www.shareware.com,
http://www.download.com,
etc.
Maar er zit nu iemand met mij mee te biedden... damn 
