Code-excited linear prediction

Code-excited linear prediction (CELP) is like a singing game where you try to guess what your friend is going to sing. When you sing, your voice changes in different ways, like going up and down or getting louder or softer. All these changes can be grouped together and called "parameters". But we don't want to send all the parameters to our friend because it takes too much time and computer power.

And that's where CELP comes in. It is a way to compress speech data so that it takes up less space and can be sent faster. First, the speech is analyzed and some of the parameters are chosen as the most important. Then these parameters are matched to a pre-defined set of parameters called "codebooks". The codebooks have a bunch of options for each parameter, so we can match the chosen parameters with the closest matching option in the codebook.

After matching, we "code" the matched parameters along with other information like the volume of the speech and the silence between words. Then we can send this coded information as a smaller file. Once our friend receives the information, they can use the same codebook to decode the information back into understandable speech.

So, the idea behind CELP is to reduce the amount of speech data that we send but still keep enough information that we can understand what is being said. It's like telling a story but only using the most important words and leaving out the extra ones that don't add much to the story.