How to create this "sound" in PT...

I have a question about a sound I keep hearing in pop records. I'm trying to figure out how it's done. There's a keyboard sound that I want to incorporate into a song. I know these are the most awful examples ever but I can't find another example quickly: Hot n Cold - Party in the USA - It shows up at the very beginning of the chorus for both these songs. It goes from like a high pitch to a low pitch. Hopefully you can hear what i'm talking about. Is it an actual keyboard sound or an effect applied to a sound? Is there a plugin sound in Xpand! that does this? Any help would be great. Thanks!

Re: How to creat this "sound" in PT... 

Those are two different fundamental sounds. Find the sound you like, put a filter on it and trigger the filter with an LFO or Mod wheel.

Re: How to creat this "sound" in PT... 

Well 1st u definitely have to find a sound that is close but it needs to be a Monophonic instead of Poly sound which u'll be able to hold 1 note & hit others while holding one creating the slide(portamento) thing... We don't know what u have so thatz up to u to find a sound...