Speech recognition is the process of understanding the words that are spoken by humans. The speech signals are captured using a microphone and the system tries to understand the words that are being captured. Speech recognition is used extensively in human computer interaction, smartphones, speech transcription, biometric systems, security, and so on.

It is important to understand the nature of speech signals before we analyze them. These signals happen to be complex mixtures of various signals. There are many different aspects of speech that contribute to its complexity. These things include emotion, accent, language, noise, and so on.

Hence it becomes difficult to robustly define a set of rules to analyze speech signals. But humans are really good at understanding speech even though it has so many variations. We seem to do it with relative ease. If we want our machines to do the same, we need to help them understand speech the same way we do.

Researchers work on...