In need of champion sounds/voices to create a soundboard.

Hello, I'm currently in the middle of developing a soundboard and Iv ran into a wall. I need access to every LoL Champion sounds/voice they make. So that's when they are attacking they might blurt something out or when they are moving.

I am aware that http://leagueoflegends.wikia.com/wiki/Category:Champion_audio has every champions sound. But I have found out that it does not have every sound and is difficult to download each sound. For example, Singed is missing many sounds and I want my soundboard to have every sound.

So I am wondering where can I access the sound files? Iv looked hard in my Riot Games > League of Legends > xxx> xxx> xxx> folders and have not found anything.

So I am assuming they are archived or League of Legends only grabs the sounds from their server when needed so people can not access them for whatever reason.

Thank you, any help is appreciated :)