Communication takes many forms in our daily lives, such as body language, text, picture, and speech. Due to its rich dimensions of character, speech is forever considered as the most effective form among those forms. The rich dimensions include a speaker's gender, emotion, attitude, health status, and identity in extra to the speech text (words). It is very important to have such information for effective communication. Signal processing considers speech from the perspective of the signal transporting information provided by the message. In practical applications, the waveform has proven to become one most useful interpretations of speech. Figure 1.1 shows the three main types of data that can be obtain from speech signals. They are Speech Text, Language, and Speaker Identification.