is there a way to lip synch a character to a sound file so its lips are moving whil sound is playing and not moving when there is a pause in the sound so it looks like the character is talking?
Do it the way the professionals do it - Either record the voice while the animation is playing, or record the voice and animate the animation to go with the voice. Or you can do what a lot of games do and make the character mouth go "Blah blah blah blah blah blah..." like anime style while they talk.
If you want to do some advanced animation stuff (like lipsynching) get Macromedia Flash. Combining Flash movies with MMF using the ActiveX Shockwave Flash Player object works like a charm. If you know a bit of Actionscript you'll be able to squeeze all Flash movies into one and load them using URL parameters.
Though it wont look completly realistic, it will accomplish alot more then just a mouth opening & closing. Try making say 3-4 different mouth positions. Like 1 wide open, 1 circled, 1 semi open with the teeth showing & basicly stare at yourself in the mirror & pay close attention to how these different positions show & effect how you talk. Then use these in your voice recordings. Like saying "oh" makes your mouth sort of circled, saying "No" tends to start out with your mouth open with your teeth showing as you make the 'n' sound & then it ends with the circle for the 'oh' sound. Hope this helps, works great for cartoons.
I actually tried to use timer and animation sinc.. it didn't work... use macromedia flash, but make sure the audio is streaming. then export the MOV or MPEG and import into flash project